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Prevalence and distribution of cervical high-risk human papillomavirus and cytological abnormalities in women living with HIV in Denmark – the SHADE

Prevalence and distribution of cervical high-risk human papillomavirus and cytological... Background: Women living with HIV (WLWH) are at increased risk of persistent human papillomavirus (HPV) infection, cervical dysplasia and cervical cancer compared with women from the general population (WGP). We assessed the prevalence and distribution of cervical high-risk (hr) HPV infection and cytological abnormalities in WLWH compared with WGP in Denmark. Predictors of HPV and cytological abnormalities were estimated in WLWH. Methods: WLWH consecutively enrolled in the Study on HIV, cervical Abnormalities and infections in women in Denmark (SHADE) in 2011 and were examined for cervical HPV and cytological abnormalities. WLWH were matched on age and prior cytological findings with WGP from an earlier study. HIV demographics were retrieved from the nationwide Danish HIV Cohort Study. Logistic regression was used to estimate predictors of hrHPV and cytological abnormalities. Results: Of 334 included WLWH 26.4 % were positive for hrHPV as opposed to 16.6 % WGP (p< 0.0001). WLWH had a higher number of multiple infections (>1 h genotype present) (38.5 % versus 25.7 %, p= 0.030). Hr genotypes in descending order of frequency were HPV58 (7.1 %), 52 (5.4 %), and 16 (4.8 %) in WLWH versus HPV16 (4.1 %), 52 (2.8 %) and 58 (2.4 %) in WGP. Predictors of hrHPV in WLWH were short duration of HAART (adjusted OR per year 0.90 (95 % CI 0.84-0.96)), AIDS prior to inclusion (adjusted OR 3.61 (95 % CI 1.75-7.46)), ≥5 lifetime sexual partners (adjusted OR 2.20 (95 % CI 1.08-4.49)), sexual debut <16 years of age (adjusted OR 2.05 (95 % CI 1.03-4.10)) and CD4 < 350 cells/μL (adjusted OR 2.53 (95 % CI 1.20-5.40)). Cytological abnormalities were prevalent in 10.4 % vs. 5.2 % (p = 0.0003) of WLWH and WGP. In WLWH with hrHPV, short duration of HAART predicted cervical dysplasia (adjusted OR per year 0.83 (95 % CI 0.71-0.97)). Conclusions: WLWH presented with more cervical hrHPV infections and cytological abnormalities, and a different distribution of hrHPV genotypes compared with WGP. Cervical hrHPV and cytological abnormalities were predicted by short duration of HAART. Keywords: Women living with HIV, High-risk human papillomavirus, Cervical cytological abnormalities, HPV vaccine, Highly active antiretroviral therapy * Correspondence: Kristina.thorsteinsson@gmail.com Department of Infectious Diseases, Hvidovre, Copenhagen University Hospital, Copenhagen, Denmark Department of Infectious Diseases, Hvidovre Hospital, Kettegaards Allé 30, 2650 Hvidovre, Denmark Full list of author information is available at the end of the article © The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 2 of 13 Background Cervical screening in Denmark Human papillomavirus (HPV) is the most common During the study period, The Danish National Board sexually transmitted disease (STD) [1] with a lifetime of Health recommended that women aged 23–49 prevalence of up to 80 % [2]. Essentially, all cases of years received cervical cytological testing every three cervical cancer (CC) are associated with high-risk HPV years and women aged 50–65 years every five years (hrHPV) [3] and worldwide approximately half a million [24]. In HIV guidelines cervical cytology is recom- women develop CC each year [4]. Women living with mended twice the first year after HIV diagnosis and HIV (WLWH) are at increased risk of persistent HPV annually thereafter [25]. infection, cervical dysplasia and CC compared with women from the general population (WGP) [5–9]. The SHADE cohort Comprehensive data on the prevalence and distribu- The SHADE cohort is a multicentre, prospective, obser- tion of HPV genotypes are informative in the planning vational cohort study of WLWH in Denmark. Study of HPV/CC screening tools and with the rollout of HPV procedures have been described previously [23]. In brief, vaccines [10]. The hrHPV genotype distribution in study participants were consecutively enrolled during Denmark [11, 12] and worldwide is well described in their outpatient visits from 1 February 2011 to 1 February WGP and globally HPV16, 18, 52, 31, and 58 predomin- 2012. Inclusion criteria were HIV-1 infection and ≥18 years ate [10, 13, 14]. Most studies suggest a different HPV of age. Exclusion criteria were prior hysterectomy, preg- genotype distribution in WLWH with increased fre- nancy, alcohol and/or drug abuse impeding adherence to quency of non-16/18 HPV genotypes, which are not the protocol. targeted by the 2-and 4-valent HPV vaccines [8, 15, 16]. Though, immune reconstitution induced by highly Interview survey active antiretroviral therapy (HAART) might decrease At entry, an interview including tobacco use, age at the prevalence of HPV and cervical dysplasia, the effect sexual debut, lifetime sexual partners, prior condyloma, of improved immunosurveillance remains controversial HPV vaccination status, and contraceptive use etc. was [6, 7]. The increased longevity gained from HAART [17] performed. The EpiData Entry program was used for may increase risk of exposure to HPV and provide the double manual data entry [26]. time required for progression to cancer. Compared with other Western countries WGP in Registries Denmark have high incidences of HPV and CC [11, 18, Civil Registration System (CRS) 19]. However, the prevalence and distribution of cervical The CRS is a national registry of all Danish residents HPV and dysplasia are unknown in WLWH in Denmark. [27]. A 10-digit personal identification number (PIN) is Denmark offers a unique setting for studies on HPV and assigned to each individual at birth or immigration. The cervical dysplasia because of the well described HPV PIN was used to link the SHADE cohort, the Danish genotype distribution in WGP in Denmark [11, 19] and HIV Cohort Study (DHCS) and the The Danish Pathology the possibility for linkage to nationwide registries on Data Bank (DPDB). HIV and cytology results. The aim of the present study was to assess the preva- Danish HIV cohort study lence and distribution of cervical hrHPV and cytological The DHCS is a prospective, observational, nationwide, abnormalities in WLWH in Denmark. Further, we aimed multicentre cohort study of all PLHIV seen at the at identifying predictors of hrHPV and cytological ab- Danish HIV clinics since 1 January 1995. The cohort has normalities in WLWH in a setting with free access to been described in detail elsewhere [22]. CC screening, healthcare and HAART. The Danish Pathology Data Bank (DPDB) Methods The DPDB contains nationwide records of all pathology Setting specimens [28]. Cytology samples prior to inclusion were Denmark has a population of 5.6 million [20] and an esti- retrieved to assess screening history and cytology results mated HIV prevalence among adults of 0.1 % [21] - one- using the Systemized Nomenclature of Medicine fourth of these being women [22]. Medical care, including (SNOMED) code of cervix uteri: T8x2*, T8x3* and T83*. HAART, is tax-paid and provided free-of-charge to all people living with HIV (PLHIV). Treatment of HIV is Data from the general population (the Horizon Study) restricted to eight specialized centres, of which six (treat- Anonymised data on HPV (from the CLART assay) and ing 97 % of Danish PLHIV) participated in the Study on cytology results from WGP included in the Danish Horizon HIV, cervical Abnormalities and infections in women in Study, Copenhagen, Denmark, were retrieved from the Denmark (SHADE) [23] (see below). authors [11]. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 3 of 13 Cytology using two models: A model where all variables but CD4 Cytological evaluation of SurePath samples was under- at inclusion was included and a model where duration of taken at Department of Pathology, Hvidovre, Copenhagen HAART and AIDS prior to inclusion were replaced by University Hospital (HVH). The outcomes were reported CD4. We only presented the OR of the CD4 count from using the Bethesda 2001 system [29] and classified as nor- the second model. mal, atypical cells of undetermined significance (ASCUS), To account for multiple testing when comparing the low-grade squamous intraepithelial lesions (LSIL), or distribution of genotypes, we applied Bonferoni cor- high-grade squamous intraepithelial lesions (HSIL) includ- rection. Therefore, in analyses of the 13 hrHPV genotypes ing atypical squamous cells - cannot exclude HSIL (ASC- p-values smaller than 0.05:13 (p < 0.0038) were considered H), atypical glandular cells (AGC) and adenocarcinoma in statistically significant. In the remaining analyses p-values situ (AIS), and finally squamous cell-and adenocarcinoma. <0.05 were considered statistically significant. For category variables with more than two outcome categories (df > 1), HPV DNA testing we controlled for repeated testing by estimating the com- Cervical samples were examined by the CLART HPV2 bined p-value. Individuals with missing explanatory values assay (Genomica, Madrid, Spain) at Department of Path- were excluded from the multiple regression analyses. The ology, HVH. PCR amplification of genotype specific validity of the model was tested using the Hosmer and HPV L1 fragments from 35 individual HPV genotypes Lemeshow Goodness-of-Fit Test. was performed including 13 hrHPV: HPV16, 18, 31, 33, SAS statistical software version 9.3 (SAS Institute Inc., 35, 39, 45, 51, 52, 56, 58, 59, and 68 [11]. Samples with Cary, NC, USA) was used for data analysis. The match- invalid outcomes were retested. The second result was ing of study participants and the HPV genotype distribu- considered definitive [11]. tion figures were performed in R 3.2.0 [32]. Statistical analysis Results Continuous variables were summarized as median and Characteristics of the cohort interquartile ranges (IQR) or mean and ranges and com- A total of 334 of the 1392 eligible WLWH in Denmark pared using the Wilcoxon rank sum test. Categorical (in the DHCS) were included. At inclusion, median age variables were reported as counts and percentages and and duration of HIV were 42.5 (IQR 36.8-48.3) and 11.3 compared using the chi-square test or Fisher’s exact test. (IQR 5.9-16.9) years (Table 1). Compared with WLWH For comparison of HPV status, genotype distribution from the DHCS not included, WLWH in SHADE were and cytology results study participants were matched 1:5 more likely to be sexually infected with HIV (p = 0.0015), to WGP on prior screening history in accordance with have higher CD4 counts (p = 0.012), and increased prob- the algorithm used in the Horizon study [11] and age abilities of being on HAART with a suppressed viral load with a tolerance of 2 years (choosing the 5 WGP numer- (p = 0.0042). Moreover, they had a higher uptake of both ically closest to the participant’s age). the annual HIV-and general population CC screening Univariate and multiple logistic regression analyses program (p< 0.0001 and p< 0.0001) and a higher were used for identifying predictors of hrHPV expressed probability of the latest cytology result being normal as odds ratios (OR) and 95 % confidence intervals (CI). (p< 0.0001) (Table 1). Nine candidate predictor variables were chosen a priori due to current knowledge on risk factors of HPV prevalence HPV [6, 30, 31]; age (18–29, 30–50 and >50 years of Of 334 participants, 326 (97.6 %) had a cervical swab age), race, age at sexual debut (<16 versus ≥ 16 years performed. Of these 295 (90.5 %) yielded sufficient DNA of age), HAART duration (years on HAART), AIDS for analysis and were matched at 1:5 with 1475 WGP prior to inclusion, smoking status, number of lifetime from the Horizon study (Fig. 1). sexual partners (<5 versus ≥ 5), use of hormonal contra- Overall HPV prevalence was higher in WLWH versus ceptives, and CD4 count at inclusion (<200, ≥200-349 WGP (26.4 % versus 16.6 %, p < 0.0001) (Table 2). Fur- and ≥350 cells/μL). ther, WLWH had a higher number of multiple infections Predictors of ASCUS or worse (ASCUS+) were esti- with more genotypes diagnosed per sample (p= 0.030 mated by including the aforementioned variables, pres- and p= 0.047) (Table 2). Median age of WGP was due to ence of cervical hrHPV and adherence to the general the age matching criteria close to that of WLWH (stated population CC screening program in the analysis. A above); 43.0 (IQR 37.0-49.0) years. The hrHPV preva- subgroup analysis was performed in WLWH with lence according to age is shown in Fig. 2. ASCUS+ and cervical hrHPV only. More WGP would have been protected by the 4-valent Duration of HAART, AIDS prior to inclusion and CD4 HPV vaccine than WLWH (p= 0.030), whereas both count are dependent covariates and where calculated groups of women would receive a similar degree of Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 4 of 13 Table 1 Characteristics of included and not included women living with HIV (WLWH) in Denmark from the Danish HIV Cohort Study (DHCS) WLWH WLWH p-value included in the study not included in the study Number of individuals 334 (24.0) 1,058 (76.0) NA Follow-up (years), median (IQR) 11.3 (5.9-16.9) 10.6 (5.5-15.9) 0.097 Follow-up time, total (person-years) 3,853 11,183 NA Age at inclusion (years), median (IQR) 42.5 (36.8-48.3) 42.0 (35.5-48.2) 0.22 Race, n(%) White 141 (42.6) 398 (39.5) 0.041 Asian 44 (13.3) 114 (11.3) Black 143 (43.2) 461 (45.7) Other 3 (0.9) 35 (3.5) (missing) (3) (50) Place of HIV transmission, n(%) Denmark 114 (37.8) 326 (34.8) 0.11 Europe + US 27 (8.9) 77 (8.2) Africa 128 (42.4) 416 (44.4) Asia 33 (10.9) 101 (10.8) Other 0 (0) 17 (1.8) (missing) (32) (121) Mode of transmission, n(%) Heterosexual 294 (91.6) 799 (83.6) 0.0015 IDU 16 (5.0) 106 (11.1) Other 11 (3.4) 51 (5.3) (missing) (13) (102) Age at sexual debut (years), mean (range) 17.3 (6–37) - NA Lifetime sexual partners, n(%) < 5 99 (29.6) - NA 5–14 135 (40.4) 15–25 45 (13.5) > 25 53 (15.9) Does not wish to respond 2 (0.6) (missing) (0) CD4 count at inclusion (cells/μL), n(%) < 200 12 (3.9) 79 (9.1) 0.012 200–350 51 (16.5) 138 (15.9) > 350 247 (79.7) 650 (75.0) (missing) (24) (191) HAART at inclusion, n(%) Yes 317 (94.9) 866 (81.8) <0.0001 No 17 (5.1) 192 (18.2) (missing) (0) (0) On HAART with Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 5 of 13 Table 1 Characteristics of included and not included women living with HIV (WLWH) in Denmark from the Danish HIV Cohort Study (DHCS) (Continued) HIV RNA < 40 copies/mL, n(%) Yes 250 (83.6) 576 (75.5) 0.0042 No 49 (16.4) 187 (24.5) (missing) (18) (103) Cervical cytology within the past 1 year, n(%) Yes 124 (37.1) 225 (21.3) <0.0001 No 210 (62.9) 833 (78.7) (missing) (0) (0) Cervical cytology within the past 3/5 years – depending on age for women age 23–65 years, n(%) Yes 227 (67.7) 429 (40.6) <0.0001 No 96 (28.7) 555 (52.5) Outside target age group 11 (3.3) 74 (7.0) (missing) (0) (0) Last cytology result, n(%) Normal 242 (72.5) 513 (48.5) <0.0001 Abnormal 9 (2.7) 21 (2.0) No prior cytology obtained 83 (24.9) 524 (49.5) HPV vaccination prior to inclusion, n(%) Yes (4-valent HPV vaccine) 4 (1.2) - NA Yes (2-valent HPV vaccine) 0 (0) Yes (do not know name of vaccine) 1 (0.3) No 329 (98.5) (missing) (0) IDU intravenous drug user, NA not applicable, HAART Highly active antiretroviral therapy, HPV Human papillomavirus a b There was no difference in distribution of race between groups if the category “other” was removed from the “Race” variable (p = 0.45), No information c d available, As recommended in women living with HIV (we studied the past year + a 3-month grace period), As recommended in the general population, where women aged 23–49 years were invited for cervical cancer screening every third year and women aged 50–65 years every fifth year (we studied the past 3/5 years + a 3-month grace period) protection from the 9-valent HPV vaccine based upon WLWH had a higher risk of HPV58 and 56 compared their HPV genotype distribution (p= 0.14) (Table 2). with WGP (p < 0.0001 and p = 0.0023) (Fig. 3), while no significant differences in hrHPV genotype distribution HPV genotype distribution were found between White and Asian WLWH com- Figure 3 shows the prevalence of hrHPV genotypes with pared with WGP (Fig. 3). respect to race: i) overall, ii) in WLWH and WGP with normal cytological findings, and iii) WLWH and WGP HPV genotype distribution in women with normal with ASCUS+. Overall, the six most frequent high-risk cytology genotypes in WLWH were HPV58 (n = 21, 7.1 %), 52 In women with normal cytology the hrHPV preva- (n = 16, 5.4 %), 16 (n = 14, 4.8 %), 51 (n = 12, 4.1 %), lence was 22.0 % in WLWH versus 13.0 % in WGP 18 (n = 10, 3.4 %) and 33 (n =10, 3.4 %) versus 16 (n =60, (p = 0.0004). HPV58 (n = 13, 5.1 %), 52 (n =11, 4.3 %), 4.1 %), 52 (n = 41, 2.8 %), 58 (n = 35, 2.4 %), 31 (n =32, 51 (n = 8, 3.1 %) versus HPV16 (n = 49, 3.5 %), 58 (n =30, 2.2 %), 51 (n = 28, 1.9 %) and 33 (n = 26, 1.8) in WGP 2.2 %) and 52 (n = 30, 2.2 %) predominated in (Fig. 3, Additional file 1: Table S1). WLWH and WGP, respectively (Fig. 3, Additional file 2: Table S2). HPV genotype distribution according to race There was no difference in prevalence of hrHPV in HPV genotype distribution in women presenting with WLWH of White, Asian and Black race (26.6 %, 16.2 % ASCUS+ and 29.0, (p = 0.30)). We compared genotype distribution In WLWH and WGP with ASCUS+ 61.8 % versus in WLWH of different races and found that Black 49.0 % were hrHPV-positive (p = 0.25). Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 6 of 13 Fig. 1 Flowchart of women living with HIV (WLWH) from the SHADE cohort and women from the general population (WGP) from the Horizon study matched 1:5 on prior screening history and age Table 2 Prevalence of high-risk human papillomavirus (HPV) in women with sufficient DNA for analyses in women living with HIV compared to women matched (1:5) on prior screening history and age from the general Danish population Women living with HIV Women from the general population p-value 295 1,475 High-risk HPV positive, n(%) Yes 78 (26.4) 245 (16.6) <0.0001 No 217 (73.6) 1,230 (83.4) Number of genotypes, mean (range) 1.54 (1–4) 1.38 (1–5) 0.047 Number of infections, n(%) Single 48 (61.5) 182 (74.3) 0.030 Multiple (>1) 30 (38.5) 63 (25.7) All high-risk genotypes present targeted by the 4-valent HPV vaccine , n(% of the HPV positive patients) Yes 8 (10.3) 52 (21.2) 0.030 No 70 (89.7) 193 (78.8) All high-risk genotypes present targeted by the 9-valent vaccine , n(% of the HPV positive patients) Yes 42 (53.9) 155 (63.3) 0.14 No 36 (46.1) 90 (36.7) Presence of ≥1 high-risk genotypes targeted by the 4-valent vaccine , n(% of the HPV positive patients) Yes 21 (26.9) 76 (31.0) 0.49 No 57 (73.1) 169 (69.0) Presence of ≥1 high-risk genotypes targeted by the 9-valent vaccine , n(% of the HPV positive patients) Yes 61 (78.2) 194 (79.2) 0.85 No 17 (21.8) 51 (20.8) Targeting HPV6, HPV11, HPV16 and HPV18. HPV6 and HPV11 are low-risk genotypes and not included in this analysis Targeting HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58. HPV6, and HPV11 are low-risk genotypes and not included in this analysis Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 7 of 13 Fig. 2 Prevalence of high-risk human papillomavirus (HPV) according to age group in women living with HIV (WLWH) and women from the general population (WGP) Distribution of genotypes in descending order in Predictors of cytological abnormalities WLWH and WGP presenting with ASCUS+ were HPV58 HrHPV predicted ASCUS+ (adjusted OR 6.91 (95 % CI (n=8,23.5%), 16 (n = 7, 20.6 %) and 56 (n=5,14.7%) 2.91-16.42)) (Additional file 4: Table S4). However, in versus HPV52 (n = 11, 14.1 %), 16 (n = 10, 12.8 %) and 45 the subgroup of WLWH with hrHPV short duration of (n = 9, 11.5 %) (Fig. 3, Additional file 3: Table S3). HAART predicted ASCUS+ (adjusted OR 0.83 (95 % CI 0.71-0.97)) (Additional file 5: Table S5). Predictors of HPV In all adjusted analyses we checked the effect of miss- Short duration of HAART (adjusted OR per year 0.90 (95 ing values on outcome by adding an extra category with % CI 0.84-0.96)), AIDS prior to inclusion (adjusted OR missing values. This had no impact on the estimates. 3.61 (95 % CI 1.75-7.46)), ≥5 lifetime sexual partners (adjusted OR 2.20 (95 % CI 1.08-4.49)), sexual debut Discussion <16 years of age (adjusted OR 2.05 (95 % CI 1.03-4.10)) In this multicentre, cross-sectional cohort study of and CD4 < 350 cells/μL(adjusted OR 2.53 (95%CI WLWH in Denmark, we found a higher prevalence of cer- 1.20-5.40)) predicted prevalent hrHPV (Table 3). vical hrHPV in WLWH compared with WGP matched on prior screening history and age. Further, WLWH had a Cervical cytological abnormalities higher number of hrHPV genotypes and more carried Five (1.5 %) of the 332 cytology samples received from multiple hrHPV infections. Presence of ≥1 genotypes WLWH were inadequate for evaluation leaving 327 for in- covered by the 9-valent HPV vaccine was higher in terpretation. These were matched with cytology results WLWH and a higher number of WGP had all present from 1635 WGP (Fig. 1). ASCUS+ was prevalent in 34 genotypes covered by the 4-valent HPV vaccine. (10.4 %) versus 85 (5.2 %) WLWH and WGP, (p = 0.0003). WLWH had a different distribution of hrHPV genotypes Cytological abnormalities in WLWH and WGP were and this difference was mainly attributed to WLWH of distributed as follows: ASCUS: 8 (2.5 %) versus 42 (2.6 %), Black race. There was a higher risk of ASCUS+ in (p = 0.90); LSIL: 20 (6.1 %) versus 23 (1.4 %), (p < 0.0001) WLWH, due to a higher prevalence of LSIL. Finally, cer- and HSIL: 6 (1.8 %) versus 20 (1.2 %), (p =0.38). No vical HPV and ASCUS+ were predicted by short duration WLWH or WGP presented with carcinoma. of HAART. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 8 of 13 Fig. 3 (See legend on next page.) Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 9 of 13 (See figure on previous page.) Fig. 3 Cervical high-risk human papillomavirus (HPV) genotype distribution in women living with HIV (WLWH) compared to women from the general population (WGP); i) overall, ii) in women with normal cervical cytology, and iii) women with atypical cells of undetermined significance (ASCUS) or worse. Distribution is presented i) overall, ii) comparing WGP to WLWH of White race, iii) comparing WGP to WLWH of Black race and iv) comparing WGP to WLWH of Asian race. Please notice the different scale on the y-axis in the “ASCUS or worse” plots HPV prevalence with HIV infection probably contribute to the HPV Prevalent HPV infection is dependent on age with a pathogenesis by preventing spontaneous clearance of peak prevalence in women in the early 20s followed by a HPV [6]. A recent study found that in WLWH every steady decline and a second, but smaller peak in women month on HAART reduced the detection risk of any ≥45 years of age attributed to either new acquisition or cervical HPV infection by 9 % [30]. Likewise, short viral persistence [2, 14]. Therefore, we chose to match duration of HAART predicted HPV in the current WLWH and WGP on age and prior cytology/histology study. Moreover, sexual behavior such as early sexual results. The overall hrHPV prevalence in WLWH of debut and ≥5 lifetime sexual partners predicted preva- 26.4 % was lower than the hrHPV prevalence found in lent HPV and so did variables associated with a com- the European MACH-1 collaborative group of WLWH promised immune system such as CD4 < 350 cells/μL with a prevalence close to 50 % [15], however partici- and AIDS prior to inclusion. pants in the MACH study were younger (median age: 35 versus 42.5 years), less likely to be on HAART (69.7 % Cytological abnormalities versus 94.9 %) and a different assay (Hybrid Capture II) Overall, WLWH had more cytological abnormalities, was used for HPV detection. On a global scale the high- due to a higher prevalence of LSIL. A higher prevalence est prevalence of HPV in WGP with normal cytological of LSIL, but not ASCUS and HSIL, in WLWH is also findings is found in Africa (24 %) [14]. Though, the over- reported by others [35]. Most LSILs are transient and all hrHPV prevalence was highest in WLWH of Black resolve within 1–2 years [36], and are most often not race, this difference was not significant. treated according to current Danish guidelines. A high proportion of WLWH included and not included in the HPV genotype distribution study; 28.7 % and 52.5 %, had not been screened for CC Studies of WGP across all continents have repeatedly in the preceding 3 to 5 years. We have previously identified hrHPV16 and 18 - accounting for about 70 % assessed low screening attendance in this cohort of of all CCs [2, 6] – to be among the most prevalent [8]. WLWH and support the idea of cytology as part of an In agreement with others we found HPV58 and 52 to be annual medical HIV review, integration of HIV care and prevailing in WLWH [8, 16]. Though, the numbers were cervical screening in a single clinic setting and targeted small, this higher risk of HPV58 was mainly carried by public health messages aimed at health care profes- women of Black race, as no significant difference in sionals at HIV centres, general practitioners and WLWH genotype distribution, was detected when comparing [37]. However, the low screening attendance does not WGP with WLWH of White and Asian race. While the explain differences in cytological abnormalities between 2-and 4-valent HPV vaccines are anticipated to reduce WLWH and WGP, since women were matched on prior the burden of HPV-related cancers in WGP [13], the screening history. impact of these HPV vaccines in WLWH is less clear. More than 20 % of WGP had all genotypes present Predictors of cervical dysplasia covered by the 4-valent HPV vaccine, whereas only Predictors of cervical dysplasia and CC are those also one-tenth of genotypes were accounted for amongst associated with HPV infection such as smoking, early WLWH. The novel 9-valent HPV-vaccine targeting sexual debut, number of lifetime sexual partners, hormo- HPV6, 11, 16, 18, 31, 33, 45, 52, and 58 has the po- nal contraceptives and STDs other than HPV [6, 7]. We tential to prevent about 90 % of CC cases in WGP if have earlier reported that only a very few of WLWH in administered before sexual onset [33] might be better SHADE presented with STDs other than HPV [23] and suited for the HIV population. therefore this variable was not adjusted for. Not surpris- ingly, hrHPV predicted ASCUS+. Since hrHPV causes Predictors of HPV most cases of dysplasia and basically all cases of CC [6], The molecular mechanisms leading to the increased this variable could blur the effect of other covariates. We risk of HPV in PLHIV are poorly understood [34]. therefore performed a sensitivity analysis in WLWH Tugizov et al. suggested that HIV-proteins enable ini- with hrHPV, and in consistence with our findings tial HPV infection by disrupting the epithelial tight regarding HPV we found that short duration of HAART junctions [34]. Moreover, immune defects associated predicted ASCUS+. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 10 of 13 Table 3 Unadjusted and adjusted odds ratios for predictors of cervical high-risk human papillomavirus (HPV) infection in women living with HIV with sufficient DNA for HPV analysis (n = 295) a b Predictors of HPV HPV-positive group HPV-negative group Unadjusted odds ratios p-value Adjusted odds ratios p-value (n = 78) (n = 151) Age at 1 February 2011 (inclusion), n(%) 18-29 years 9 (11.5) 9 (4.2) 1.00 - 1.00 - 30-50 years 51 (65.4) 161 (74.2) 0.32 (0.12-0.84) 0.02 0.43 (0.14-1.33) 0.14 > 50 years 18 (23.1) 47 (21.7) 0.38 (0.13-1.12) 0.08 0.51 (0.13-1.92) 0.32 (missing) 0 (0) (0) Combined p-value 0.068 0.32 Race, n(%) White 34 (44.7) 94 (44.1) 1.00 - 1.00 - Asian 6 (7.9) 31 (14.6) 0.54 (0.21-1.40) 0.20 0.67 (0.23-1.92) 0.46 Black 36 (47.4) 88 (41.3) 1.13 (0.65-1.96) 0.66 0.38 (0.67-2.87) 0.38 (missing) (2) (4) - - Combined p-value 0.31 0.35 Sexual debut, n(%) ≥ 16 years of age 51 (65.4) 160 (73.7) 1.00 - 1.00 - < 16 years of age 27 (34.6) 57 (26.3) 1.49 (0.85-2.59) 0.16 2.05 (1.03-4.10) 0.042 (missing) (0) (0) - HAART duration, (years) Median (IQR) 4.6 (2.0-10.4) 8.8 (4.6-12.2) 0.91 (0.86-0.96) 0.0013 0.90 (0.84-0.96) 0.0011 (missing) (2) (9) AIDS prior to inclusion, n(%) No 55 (71.4) 191 (88.4) 1.00 - 1.00 - Yes 22 (28.6) 25 (11.6) 0.33 (0.17-0.63) 0.0007 3.61 (1.75-7.46) 0.0005 (missing) (1) (1) Smoking status, n(%) Current smoker/Ex-smoker 33 (42.3) 92 (42.4) 1.00 - 1.00 - Never smoker 45 (57.7) 125 (57.6) 1.00 (0.59-1.69) 0.99 1.31 (0.65-2.63) 0.45 (missing) (0) (0) Number of lifetime sexual partners at inclusion, n(%) < 5 36 (25.0) 54 (36.0) 1.00 - 1.00 - ≥ 5 108 (75.0) 96 (64.0) 1.83 (1.00-3.36) 0.05 2.20 (1.08-4.49) 0.03 (missing) (0) (1) Use of hormonal contraceptives, n(%) 12 (8.3) 9 (6.0) 1.00 - 1.00 - Yes 132 (91.7) 142 (94.0) 0.89 (0.33-2.38) 0.82 1.29 (0.40-4.10) 0.67 No (0) (0) (missing) CD4 count at inclusion (cells/μL), > 350 45 (69.2) 173 (83.2) 1.00 - 1.00 - 200-350 15 (23.1) 28 (13.5) 2.06 (1.02-4.18) 0.045 2.53 (1.20-5.40) 0.015 < 200 5 (7.7) 7 (3.4) 2.75 (0.83-9.06) 0.10 2.70 (0.78-9.33) 0.12 (missing) (13) (9) Combined p-value 0.0496 0.023 HAART = Highly active antiretroviral therapy Two models are shown in the table: Age, race, sexual debut, smoking status, number of lifetime sexual partners and use of hormonal contraceptives were included in both models, whereas HAART duration and AIDS prior to inclusion were included in the first model and replaced by CD4 at inclusion inthe second model, We only presented the ORs of the CD4 count from the second model, The validity of the model was tested using the Hosmer and Lemeshow Goodness-of-Fit Test Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 11 of 13 Strengths and limitations MSM: Men who have sex with men; OR: Odds ratio; PIN: Personal identification number; PLHIV: People living with HIV; SHADE: Study on HIV, We have a very well-described cohort due to the DHCS cervical Abnormalities and infections in women in Denmark; STD: Sexually and DPDB and were able to match on prior cytological transmitted diseases; WGP: Women from the general population; outcomes. Compared to other Western countries Danish WLWH: Women living with HIV women represent a CC high-risk population [18], there- fore comparison to WGP is essential in interpretation of Acknowledgements We are first and foremost grateful to all the women living with HIV for results. participating in the study. We further thank the staff of our clinical Possible limitations are that WLWH included in departments for their continuous support and enthusiasm at the SHADE were more likely to comply with CC screening participating centres in the SHADE cohort: Department of Infectious Diseases, Hvidovre, Copenhagen University Hospital (AM Lebech, K programs and to have a previous normal cytology result. Thorsteinsson); Department of Infectious Diseases, Copenhagen University Therefore estimates regarding cytological abnormalities Hospitals, Rigshospitalet (TL Katzenstein, FF Rönsholt); Department of in WLWH might be conservative. The effect of HAART Infectious Diseases, Odense University Hospital (IS Johansen); Department of Infectious Diseases, Aarhus University Hospitals, Skejby (M Storgaard); duration can be confounded by other time-scales such Department of Infectious Diseases, Aalborg University Hospital (G Pedersen); as duration of HIV. Moreover, racial origin of the WGP Department of Infectious Diseases, Hillerød Hospital (LN Nielsen). Moreover, group was not available for direct comparison to the we are grateful to the study group behind the Horizon Study for providing us with data on women from the general population. SHADE cohort. Furthermore, a higher number of inad- equate HPV samples were collected in the present study Funding compared to ordinary CC screening samples included in This work was supported by the Danish Cancer Society and the AIDS the Horizon study, probably as a consequence of sam- Foundation; the Aragon Foundation; the Foundation of Aase and Ejnar pling by personnel less trained in gynecological routines. Danielsens and the Foundation of Anna and Preben Simonsen. Grant numbers do not apply in a Danish setting. The sponsors of the study had no Finally, this is a cross-sectional study giving information role in study design, data collection, data analysis, data interpretation or on HPV infection at the time of one single sampling. writing of the article. The limitation in this design is that without previous or subsequent sampling results, any HPV infection ob- Availability of data and materials served may be a transient infection. We believe that all data of relevance for the present study is available within the manuscript and in the Additional file 1: Table S1, Additional file 2: Table S2, Additional file 3: Table S3, Additional file 4: Table S4 and Additional file 5: Conclusions Table S5. We are open to collaboration and in involving other researchers in our work. However, we strongly feel that we cannot make a full dataset WLWH had a higher risk of being cervical hrHPV posi- publicly available for the following reasons: We are extremely concerned tive, a higher frequency of multiple infections, a different about confidentiality – since these patients may be identified by genotype distribution and more cytological abnormalities combinations of person-specific characteristics within the database, and the database includes sensitive data such as HIV status, previous diagnosis of than WGP. Cervical HPV and ASCUS+ were predicted by AIDS, data on intravenous drug use and sexual preferences. Further we are short duration of HAART. concerned that public access to our dataset would compromise our ability to publish future articles on WLWH included in the SHADE. Additional files Authors’ contributions Additional file 1: Table S1. Comparison of the overall prevalence KT contributed to conception and design of the study, included patients, of high-risk HPV genotypes in women living with HIV (WLWH) and performed interviews and gynaecological examinations, analysed and age-matched women from the general population (WGP). (DOCX 20 kb) interpreted data, and drafted the manuscript. SL, biostatistician, was involved in analysis and interpretation of data, and critically reviewed the manuscript. Additional file 2: Table S2. Comparison of the prevalence of high-risk MS contributed to conception and design of the study, included patients, HPV genotypes in women living with HIV (WLWH) and women from the performed interviews and gynaecological examinations, and critically general population (WGP) with normal cytological findings. (DOCX 20 kb) reviewed the manuscript. TLK contributed to conception and design of the Additional file 3: Table S3. Comparison of the prevalence of high-risk study, included patients, performed interviews and gynaecological HPV genotypes in women living with HIV (WLWH) and women from the examinations, and critically reviewed the manuscript. FR included patients, general population (WGP) with abnormal cytological findings (ASCUS or performed interviews and gynaecological examinations, and critically worse). (DOCX 20 kb) reviewed the manuscript. ISJ contributed to conception and design of the Additional file 4: Table S4. Unadjusted and adjusted odds ratios for study, included patients, performed interviews and gynaecological predictors of ASCUS or worse (ASCUS+) in women living with HIV with examinations, and critically reviewed the manuscript. GP included patients, adequate cytology samples. (DOCX 27 kb) performed interviews, and critically reviewed the manuscript. LH, performed gynaecological examinations and critically reviewed the manuscript. LNN Additional file 5: Table S5. Unadjusted and adjusted odds ratios included patients and performed interviews, and critically reviewed the for predictors of ASCUS or worse in women living with HIV with manuscript. LN, performed gynaecological examinations in WLWH needing adequate cytology samples and positive for cervical high-risk human follow-up and provided valuable information on gynaecological procedures papillomavirus. (DOCX 26 kb) in Denmark, and critically reviewed the manuscript. JB was in charge of the analyses of HPV, and critically reviewed the manuscript. NO, head of the Abbreviations DHCS, critically reviewed the manuscript. AML, principal investigator, CC: Cervical cancer; CI: Confidence interval; CRS: Civil Registration System; contributed to conception and design of the study, included patients and DF: Degrees of freedom; DHCS: Danish HIV Cohort Study; DPDB: The Danish performed interviews and gynaecological examinations, was involved in Pathology Data Bank; HAART: Highly active antiretroviral therapy; analysis and interpretation of data, and critically reviewed the manuscript. HPV: Human papillomavirus; HVH: Hvidovre, Copenhagen University Hospital; All authors read and approved the final manuscript. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 12 of 13 Competing interests 7. Rocha-Brischiliari SC, Gimenes F, de Abreu AL, Irie MM, Souza RP, Santana KT has received research funding from Abbott and honoraria from Janssen- RG, et al. Risk factors for cervical HPV infection and genotypes distribution Cilag, BMS and GlaxoSmithKline/Viiv. JB has in the past served as paid advisor in HIV-infected South Brazilian women. Infect Agent Cancer. 2014;9:6. or advisory board member to Roche Molecular Systems, Genomica SAU, and 8. McKenzie ND, Kobetz EN, Hnatyszyn J, Twiggs LB, Lucci III JA. Women with BD Diagnostics. He has received honoraria from Roche, Qiagen, Hologic, HIV are more commonly infected with non-16 and −18 high-risk HPV types. Genomica and Bd Diagnostics for lectures. HW has received research Gynecol Oncol. 2010;116:572–7. funding and honoraria from Roche Molecular, Hologic, and Novo Nordic. 9. Denslow SA, Rositch AF, Firnhaber C, Ting J, Smith JS. Incidence and TLK has received research funding and/or honoraria from Bristol-Myers progression of cervical lesions in women with HIV: a systematic global Squibb, Merck Sharp & Dohme, GlaxoSmithKline/Viiv, Abbott, Gilead, review. Int J STD AIDS. 2014;25:163–77. and Janssen-Cilag. AML has received research funding from Abbott 10. Ogembo RK, Gona PN, Seymour AJ, Park HS, Bain PA, Maranda L, et al. and honoraria from Bristol-Myers Squibb, Merck Sharp & Dohme, Prevalence of human papillomavirus genotypes among African women GlaxoSmithKline, Boehringer Ingelheim and Janssen-Cilag. SL, MS, with normal cervical cytology and neoplasia: a systematic review and FR, IJ, LH, LNN, LN and NO report no conflicts of interest. meta-analysis. PLoS One. 2015;10:e0122488. 11. Bonde J, Rebolj M, Ejegod DM, Preisler S, Lynge E, Rygaard C. HPV Consent to publish prevalence and genotype distribution in a population-based split-sample Not applicable. study of well-screened women using CLART HPV2 human papillomavirus genotype microarray system. BMC Infect Dis. 2014;14:413–4. doi:10.1186/ 1471-2334-14-413. Ethics approval and consent to participate 12. Kjaer SK, Munk C, Junge J, Iftner T. Carcinogenic HPV prevalence and At entry, written and oral informed consent was obtained from all age-specific type distribution in 40,382 women with normal cervical participants. The study and the DHCS were approved by the Danish Data cytology, ASCUS/LSIL, HSIL, or cervical cancer: what is the potential for Protection Agency (2015-231-0126, 2012-58-0004 and 2012-41-0005). Further, prevention? Cancer Causes Control. 2014;25:179–89. the study was approved by the Danish Regional Committee on Health 13. Saraiya M, Unger ER, Thompson TD, Lynch CF, Hernandez BY, Lyu CW et al. Research Ethics (approval numbers: H-3-2010-119 and H-2-2014-102). US Assessment of HPV Types in Cancers: Implications for Current and 9- Valent HPV Vaccines. J Natl Cancer Inst. 2015;107(6). Meetings where the work has been presented 14. Bruni L, Diaz M, Castellsague X, Ferrer E, Bosch FX, de SS. Cervical human Oral at the 15th European AIDS Conference in Barcelona, Spain, October nd papillomavirus prevalence in 5 continents: meta-analysis of 1 million 21–24, 2015. Oral at the 2 Nordic HIV & Women Meeting, Copenhagen, women with normal cytological findings. J Infect Dis. 2010;202:1789–99. December 9, 2015. 15. Heard I, Cubie HA, Mesher D, Sasieni P. Characteristics of HPV infection over time in European women who are HIV-1 positive. BJOG. 2013;120:41–9. Author details 16. Heard I. Human papillomavirus, cancer and vaccination. Curr Opin HIV AIDS. Department of Infectious Diseases, Hvidovre, Copenhagen University 2011;6:297–302. Hospital, Copenhagen, Denmark. Department of Infectious Diseases, Skejby, 17. Obel N, Omland LH, Kronborg G, Larsen CS, Pedersen C, Pedersen G, Aarhus University Hospital, Aarhus, Denmark. Department of Infectious et al. Impact of non-HIV and HIV risk factors on survival in HIV-infected Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, patients on HAART: a population-based nationwide cohort study. PLoS Denmark. Institute of Clinical Medicine, University of Copenhagen, One. 2011;6:e22698. Copenhagen, Denmark. Clinical Research Center, Hvidovre, Copenhagen 18. Nygard M, Hansen BT, Dillner J, Munk C, Oddsson K, Tryggvadottir L, et al. University Hospital, Copenhagen, Denmark. Department of Infectious Targeting human papillomavirus to reduce the burden of cervical, vulvar Diseases, Odense University Hospital, Odense, Denmark. Department of and vaginal cancer and pre-invasive neoplasia: establishing the baseline for Infectious Diseases, Aalborg University Hospital, Aalborg, Denmark. surveillance. PLoS One. 2014;9:e88323. Department of Obstetrics and Gynaecology, Aalborg University Hospital, Aalborg, Denmark. Department of Infectious Diseases, Nordsjællands 19. Kjaer SK, Breugelmans G, Munk C, Junge J, Watson M, Iftner T. Population- Hospital, Hillerød, Denmark. Department of Obstetrics and Gynaecology, based prevalence, type- and age-specific distribution of HPV in women Hvidovre, Copenhagen University Hospital, Copenhagen, Denmark. before introduction of an HPV-vaccination program in Denmark. Int Molecular Pathology Laboratory, Department of Pathology, Hvidovre, J Cancer. 2008;123:1864–70. Copenhagen University Hospital, Copenhagen, Denmark. Department of 20. http://www.dst.dk/da/Statistik/emner/befolkning-og-befolkningsfremskrivning/ Infectious Diseases, Hvidovre Hospital, Kettegaards Allé 30, 2650 Hvidovre, folketal.aspx. Accessed on 14 Sept 2012. Webpage in Danish. 14-9-2012. Ref Denmark. Type: Internet Communication 21. http://www.ssi.dk/Service/Sygdomsleksikon/H/AIDS%20-%20HIV.aspx. Received: 24 May 2016 Accepted: 24 October 2016 Accessed on September 14th 2012. Webpage in Danish. 14 Sept 2012. Ref Type: Internet Communication 22. Obel N, Engsig FN, Rasmussen LD, Larsen MV, Omland LH, Sorensen HT. Cohort profile: the Danish HIV cohort study. Int J Epidemiol. 2009;38:1202–6. References 23. Thorsteinsson K, Ladelund S, Storgaard M, Ronsholt FF, Johansen IS, 1. Markowitz LE, Dunne EF, Saraiya M, Chesson HW, Curtis CR, Gee J, et al. Pedersen G, et al. Sexually transmitted infections and use of contraceptives Human papillomavirus vaccination: recommendations of the Advisory in women living with HIV in Denmark - the SHADE cohort. BMC Infect Dis. Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2016;16:81. 2014;63:1–30. 24. Screening of cervical cancer - recommendations 2007. The Danish National 2. Juckett G, Hartman-Adams H. Human papillomavirus: clinical manifestations Board of Health. Available from: http://sundhedsstyrelsen.dk/publ/Publ2007/ and prevention. Am Fam Physician. 2010;82:1209–13. PLAN/Kraeft/Anbef_screen_livmoderhals.pdf. Article in Danish. Summary in 3. Walboomers JM, Jacobs MV, Manos MM, Bosch FX, Kummer JA, Shah KV, English. Accessed on 22nd May 2015. 22-5-2015. 22-5-2015. Ref Type: et al. Human papillomavirus is a necessary cause of invasive cervical cancer Internet Communication worldwide. J Pathol. 1999;189:12–9. 25. Kaplan JE, Benson C, Holmes KH, Brooks JT, Pau A, Masur H. Guidelines for 4. Cervical Cancer. Estimated Incidence, Mortality and Prevalence Worldwide prevention and treatment of opportunistic infections in HIV-infected adults in 2012. Globocan 2012. WHO. http://globocan.iarc.fr/old/FactSheets/ and adolescents: recommendations from CDC, the National Institutes of cancers/cervix-new.asp. Accessed on 21 Dec 2015. 21-12-2015. 21-12-2015. Health, and the HIV Medicine Association of the Infectious Diseases Society Ref Type: Internet Communication. of America. MMWR Recomm Rep. 2009;58:1–207. 5. Chaturvedi AK, Madeleine MM, Biggar RJ, Engels EA. Risk of human papillomavirus-associated cancers among persons with AIDS. J Natl Cancer 26. Lauritsen JM & Bruus M. EpiData (version 3.1). A comprehensive tool for Inst. 2009;101:1120–30. validated entry and documentation of data. The EpiData Association, 6. Brickman C, Palefsky JM. Human papillomavirus in the HIV-infected host: Odense, Denmark, 2003–2005. 11-2-2015. Ref Type: Generic. epidemiology and pathogenesis in the antiretroviral Era. Curr HIV/AIDS 27. Pedersen CB. The Danish civil registration system. Scand J Public Health. Rep. 2015;12:6–15. 2011;39:22–5. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 13 of 13 28. Erichsen R, Lash TL, Hamilton-Dutoit SJ, Bjerregaard B, Vyberg M, Pedersen L. Existing data sources for clinical epidemiology: the Danish National Pathology Registry and Data Bank. Clin Epidemiol. 2010;2:51–6. 29. Solomon D, Davey D, Kurman R, Moriarty A, O'Connor D, Prey M, et al. The 2001 Bethesda System: terminology for reporting results of cervical cytology. JAMA. 2002;287:2114–9. 30. Zeier MD, Botha MH, Engelbrecht S, Machekano RN, Jacobs GB, Isaacs S, et al. Combination antiretroviral therapy reduces the detection risk of cervical human papilloma virus infection in women living with HIV. AIDS. 2015;29:59–66. 31. Marks MA, Gupta S, Liaw KL, Tadesse A, Kim E, Phongnarisorn C, et al. Prevalence and correlates of HPV among women attending family-planning clinics in Thailand. BMC Infect Dis. 2015;15:159. 32. R Core Team (2015). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http:// www.R-project.org/. Accessed 24 June 2015. 24-6-2015. 24-6-2015. Ref Type: Internet Communication 33. Serrano B, Alemany L, Tous S, Bruni L, Clifford GM, Weiss T, et al. Potential impact of a nine-valent vaccine in human papillomavirus related cervical disease. Infect Agent Cancer. 2012;7:38. 34. Tugizov SM, Herrera R, Chin-Hong P, Veluppillai P, Greenspan D, Michael BJ, et al. HIV-associated disruption of mucosal epithelium facilitates paracellular penetration by human papillomavirus. Virology. 2013;446:378–88. 35. Micheletti AM, Dutra VF, Murta EF, Paschoini MC, Silva-Vergara ML, Barbosa e Silva, et al. Cervicovaginal cytological abnormalities in patients with human immunodeficiency virus infection, in relation to disease stage, CD4 cell count and viral load. Diagn Cytopathol. 2009;37:164–9. 36. Rodriguez AC, Schiffman M, Herrero R, Wacholder S, Hildesheim A, Castle PE, et al. Rapid clearance of human papillomavirus and implications for clinical focus on persistent infections. J Natl Cancer Inst. 2008;100:513–7. 37. Thorsteinsson K, Ladelund S, Jensen-Fangel S, Katzenstein TL, Johansen IS, Pedersen G, et al. Adherence to the cervical cancer screening program in women living with HIV in Denmark: comparison with the general population. BMC Infect Dis. 2014;14:256. 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Prevalence and distribution of cervical high-risk human papillomavirus and cytological abnormalities in women living with HIV in Denmark – the SHADE

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Pubmed Central
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© The Author(s). 2016
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1471-2407
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1471-2407
DOI
10.1186/s12885-016-2881-1
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Abstract

Background: Women living with HIV (WLWH) are at increased risk of persistent human papillomavirus (HPV) infection, cervical dysplasia and cervical cancer compared with women from the general population (WGP). We assessed the prevalence and distribution of cervical high-risk (hr) HPV infection and cytological abnormalities in WLWH compared with WGP in Denmark. Predictors of HPV and cytological abnormalities were estimated in WLWH. Methods: WLWH consecutively enrolled in the Study on HIV, cervical Abnormalities and infections in women in Denmark (SHADE) in 2011 and were examined for cervical HPV and cytological abnormalities. WLWH were matched on age and prior cytological findings with WGP from an earlier study. HIV demographics were retrieved from the nationwide Danish HIV Cohort Study. Logistic regression was used to estimate predictors of hrHPV and cytological abnormalities. Results: Of 334 included WLWH 26.4 % were positive for hrHPV as opposed to 16.6 % WGP (p< 0.0001). WLWH had a higher number of multiple infections (>1 h genotype present) (38.5 % versus 25.7 %, p= 0.030). Hr genotypes in descending order of frequency were HPV58 (7.1 %), 52 (5.4 %), and 16 (4.8 %) in WLWH versus HPV16 (4.1 %), 52 (2.8 %) and 58 (2.4 %) in WGP. Predictors of hrHPV in WLWH were short duration of HAART (adjusted OR per year 0.90 (95 % CI 0.84-0.96)), AIDS prior to inclusion (adjusted OR 3.61 (95 % CI 1.75-7.46)), ≥5 lifetime sexual partners (adjusted OR 2.20 (95 % CI 1.08-4.49)), sexual debut <16 years of age (adjusted OR 2.05 (95 % CI 1.03-4.10)) and CD4 < 350 cells/μL (adjusted OR 2.53 (95 % CI 1.20-5.40)). Cytological abnormalities were prevalent in 10.4 % vs. 5.2 % (p = 0.0003) of WLWH and WGP. In WLWH with hrHPV, short duration of HAART predicted cervical dysplasia (adjusted OR per year 0.83 (95 % CI 0.71-0.97)). Conclusions: WLWH presented with more cervical hrHPV infections and cytological abnormalities, and a different distribution of hrHPV genotypes compared with WGP. Cervical hrHPV and cytological abnormalities were predicted by short duration of HAART. Keywords: Women living with HIV, High-risk human papillomavirus, Cervical cytological abnormalities, HPV vaccine, Highly active antiretroviral therapy * Correspondence: Kristina.thorsteinsson@gmail.com Department of Infectious Diseases, Hvidovre, Copenhagen University Hospital, Copenhagen, Denmark Department of Infectious Diseases, Hvidovre Hospital, Kettegaards Allé 30, 2650 Hvidovre, Denmark Full list of author information is available at the end of the article © The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 2 of 13 Background Cervical screening in Denmark Human papillomavirus (HPV) is the most common During the study period, The Danish National Board sexually transmitted disease (STD) [1] with a lifetime of Health recommended that women aged 23–49 prevalence of up to 80 % [2]. Essentially, all cases of years received cervical cytological testing every three cervical cancer (CC) are associated with high-risk HPV years and women aged 50–65 years every five years (hrHPV) [3] and worldwide approximately half a million [24]. In HIV guidelines cervical cytology is recom- women develop CC each year [4]. Women living with mended twice the first year after HIV diagnosis and HIV (WLWH) are at increased risk of persistent HPV annually thereafter [25]. infection, cervical dysplasia and CC compared with women from the general population (WGP) [5–9]. The SHADE cohort Comprehensive data on the prevalence and distribu- The SHADE cohort is a multicentre, prospective, obser- tion of HPV genotypes are informative in the planning vational cohort study of WLWH in Denmark. Study of HPV/CC screening tools and with the rollout of HPV procedures have been described previously [23]. In brief, vaccines [10]. The hrHPV genotype distribution in study participants were consecutively enrolled during Denmark [11, 12] and worldwide is well described in their outpatient visits from 1 February 2011 to 1 February WGP and globally HPV16, 18, 52, 31, and 58 predomin- 2012. Inclusion criteria were HIV-1 infection and ≥18 years ate [10, 13, 14]. Most studies suggest a different HPV of age. Exclusion criteria were prior hysterectomy, preg- genotype distribution in WLWH with increased fre- nancy, alcohol and/or drug abuse impeding adherence to quency of non-16/18 HPV genotypes, which are not the protocol. targeted by the 2-and 4-valent HPV vaccines [8, 15, 16]. Though, immune reconstitution induced by highly Interview survey active antiretroviral therapy (HAART) might decrease At entry, an interview including tobacco use, age at the prevalence of HPV and cervical dysplasia, the effect sexual debut, lifetime sexual partners, prior condyloma, of improved immunosurveillance remains controversial HPV vaccination status, and contraceptive use etc. was [6, 7]. The increased longevity gained from HAART [17] performed. The EpiData Entry program was used for may increase risk of exposure to HPV and provide the double manual data entry [26]. time required for progression to cancer. Compared with other Western countries WGP in Registries Denmark have high incidences of HPV and CC [11, 18, Civil Registration System (CRS) 19]. However, the prevalence and distribution of cervical The CRS is a national registry of all Danish residents HPV and dysplasia are unknown in WLWH in Denmark. [27]. A 10-digit personal identification number (PIN) is Denmark offers a unique setting for studies on HPV and assigned to each individual at birth or immigration. The cervical dysplasia because of the well described HPV PIN was used to link the SHADE cohort, the Danish genotype distribution in WGP in Denmark [11, 19] and HIV Cohort Study (DHCS) and the The Danish Pathology the possibility for linkage to nationwide registries on Data Bank (DPDB). HIV and cytology results. The aim of the present study was to assess the preva- Danish HIV cohort study lence and distribution of cervical hrHPV and cytological The DHCS is a prospective, observational, nationwide, abnormalities in WLWH in Denmark. Further, we aimed multicentre cohort study of all PLHIV seen at the at identifying predictors of hrHPV and cytological ab- Danish HIV clinics since 1 January 1995. The cohort has normalities in WLWH in a setting with free access to been described in detail elsewhere [22]. CC screening, healthcare and HAART. The Danish Pathology Data Bank (DPDB) Methods The DPDB contains nationwide records of all pathology Setting specimens [28]. Cytology samples prior to inclusion were Denmark has a population of 5.6 million [20] and an esti- retrieved to assess screening history and cytology results mated HIV prevalence among adults of 0.1 % [21] - one- using the Systemized Nomenclature of Medicine fourth of these being women [22]. Medical care, including (SNOMED) code of cervix uteri: T8x2*, T8x3* and T83*. HAART, is tax-paid and provided free-of-charge to all people living with HIV (PLHIV). Treatment of HIV is Data from the general population (the Horizon Study) restricted to eight specialized centres, of which six (treat- Anonymised data on HPV (from the CLART assay) and ing 97 % of Danish PLHIV) participated in the Study on cytology results from WGP included in the Danish Horizon HIV, cervical Abnormalities and infections in women in Study, Copenhagen, Denmark, were retrieved from the Denmark (SHADE) [23] (see below). authors [11]. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 3 of 13 Cytology using two models: A model where all variables but CD4 Cytological evaluation of SurePath samples was under- at inclusion was included and a model where duration of taken at Department of Pathology, Hvidovre, Copenhagen HAART and AIDS prior to inclusion were replaced by University Hospital (HVH). The outcomes were reported CD4. We only presented the OR of the CD4 count from using the Bethesda 2001 system [29] and classified as nor- the second model. mal, atypical cells of undetermined significance (ASCUS), To account for multiple testing when comparing the low-grade squamous intraepithelial lesions (LSIL), or distribution of genotypes, we applied Bonferoni cor- high-grade squamous intraepithelial lesions (HSIL) includ- rection. Therefore, in analyses of the 13 hrHPV genotypes ing atypical squamous cells - cannot exclude HSIL (ASC- p-values smaller than 0.05:13 (p < 0.0038) were considered H), atypical glandular cells (AGC) and adenocarcinoma in statistically significant. In the remaining analyses p-values situ (AIS), and finally squamous cell-and adenocarcinoma. <0.05 were considered statistically significant. For category variables with more than two outcome categories (df > 1), HPV DNA testing we controlled for repeated testing by estimating the com- Cervical samples were examined by the CLART HPV2 bined p-value. Individuals with missing explanatory values assay (Genomica, Madrid, Spain) at Department of Path- were excluded from the multiple regression analyses. The ology, HVH. PCR amplification of genotype specific validity of the model was tested using the Hosmer and HPV L1 fragments from 35 individual HPV genotypes Lemeshow Goodness-of-Fit Test. was performed including 13 hrHPV: HPV16, 18, 31, 33, SAS statistical software version 9.3 (SAS Institute Inc., 35, 39, 45, 51, 52, 56, 58, 59, and 68 [11]. Samples with Cary, NC, USA) was used for data analysis. The match- invalid outcomes were retested. The second result was ing of study participants and the HPV genotype distribu- considered definitive [11]. tion figures were performed in R 3.2.0 [32]. Statistical analysis Results Continuous variables were summarized as median and Characteristics of the cohort interquartile ranges (IQR) or mean and ranges and com- A total of 334 of the 1392 eligible WLWH in Denmark pared using the Wilcoxon rank sum test. Categorical (in the DHCS) were included. At inclusion, median age variables were reported as counts and percentages and and duration of HIV were 42.5 (IQR 36.8-48.3) and 11.3 compared using the chi-square test or Fisher’s exact test. (IQR 5.9-16.9) years (Table 1). Compared with WLWH For comparison of HPV status, genotype distribution from the DHCS not included, WLWH in SHADE were and cytology results study participants were matched 1:5 more likely to be sexually infected with HIV (p = 0.0015), to WGP on prior screening history in accordance with have higher CD4 counts (p = 0.012), and increased prob- the algorithm used in the Horizon study [11] and age abilities of being on HAART with a suppressed viral load with a tolerance of 2 years (choosing the 5 WGP numer- (p = 0.0042). Moreover, they had a higher uptake of both ically closest to the participant’s age). the annual HIV-and general population CC screening Univariate and multiple logistic regression analyses program (p< 0.0001 and p< 0.0001) and a higher were used for identifying predictors of hrHPV expressed probability of the latest cytology result being normal as odds ratios (OR) and 95 % confidence intervals (CI). (p< 0.0001) (Table 1). Nine candidate predictor variables were chosen a priori due to current knowledge on risk factors of HPV prevalence HPV [6, 30, 31]; age (18–29, 30–50 and >50 years of Of 334 participants, 326 (97.6 %) had a cervical swab age), race, age at sexual debut (<16 versus ≥ 16 years performed. Of these 295 (90.5 %) yielded sufficient DNA of age), HAART duration (years on HAART), AIDS for analysis and were matched at 1:5 with 1475 WGP prior to inclusion, smoking status, number of lifetime from the Horizon study (Fig. 1). sexual partners (<5 versus ≥ 5), use of hormonal contra- Overall HPV prevalence was higher in WLWH versus ceptives, and CD4 count at inclusion (<200, ≥200-349 WGP (26.4 % versus 16.6 %, p < 0.0001) (Table 2). Fur- and ≥350 cells/μL). ther, WLWH had a higher number of multiple infections Predictors of ASCUS or worse (ASCUS+) were esti- with more genotypes diagnosed per sample (p= 0.030 mated by including the aforementioned variables, pres- and p= 0.047) (Table 2). Median age of WGP was due to ence of cervical hrHPV and adherence to the general the age matching criteria close to that of WLWH (stated population CC screening program in the analysis. A above); 43.0 (IQR 37.0-49.0) years. The hrHPV preva- subgroup analysis was performed in WLWH with lence according to age is shown in Fig. 2. ASCUS+ and cervical hrHPV only. More WGP would have been protected by the 4-valent Duration of HAART, AIDS prior to inclusion and CD4 HPV vaccine than WLWH (p= 0.030), whereas both count are dependent covariates and where calculated groups of women would receive a similar degree of Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 4 of 13 Table 1 Characteristics of included and not included women living with HIV (WLWH) in Denmark from the Danish HIV Cohort Study (DHCS) WLWH WLWH p-value included in the study not included in the study Number of individuals 334 (24.0) 1,058 (76.0) NA Follow-up (years), median (IQR) 11.3 (5.9-16.9) 10.6 (5.5-15.9) 0.097 Follow-up time, total (person-years) 3,853 11,183 NA Age at inclusion (years), median (IQR) 42.5 (36.8-48.3) 42.0 (35.5-48.2) 0.22 Race, n(%) White 141 (42.6) 398 (39.5) 0.041 Asian 44 (13.3) 114 (11.3) Black 143 (43.2) 461 (45.7) Other 3 (0.9) 35 (3.5) (missing) (3) (50) Place of HIV transmission, n(%) Denmark 114 (37.8) 326 (34.8) 0.11 Europe + US 27 (8.9) 77 (8.2) Africa 128 (42.4) 416 (44.4) Asia 33 (10.9) 101 (10.8) Other 0 (0) 17 (1.8) (missing) (32) (121) Mode of transmission, n(%) Heterosexual 294 (91.6) 799 (83.6) 0.0015 IDU 16 (5.0) 106 (11.1) Other 11 (3.4) 51 (5.3) (missing) (13) (102) Age at sexual debut (years), mean (range) 17.3 (6–37) - NA Lifetime sexual partners, n(%) < 5 99 (29.6) - NA 5–14 135 (40.4) 15–25 45 (13.5) > 25 53 (15.9) Does not wish to respond 2 (0.6) (missing) (0) CD4 count at inclusion (cells/μL), n(%) < 200 12 (3.9) 79 (9.1) 0.012 200–350 51 (16.5) 138 (15.9) > 350 247 (79.7) 650 (75.0) (missing) (24) (191) HAART at inclusion, n(%) Yes 317 (94.9) 866 (81.8) <0.0001 No 17 (5.1) 192 (18.2) (missing) (0) (0) On HAART with Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 5 of 13 Table 1 Characteristics of included and not included women living with HIV (WLWH) in Denmark from the Danish HIV Cohort Study (DHCS) (Continued) HIV RNA < 40 copies/mL, n(%) Yes 250 (83.6) 576 (75.5) 0.0042 No 49 (16.4) 187 (24.5) (missing) (18) (103) Cervical cytology within the past 1 year, n(%) Yes 124 (37.1) 225 (21.3) <0.0001 No 210 (62.9) 833 (78.7) (missing) (0) (0) Cervical cytology within the past 3/5 years – depending on age for women age 23–65 years, n(%) Yes 227 (67.7) 429 (40.6) <0.0001 No 96 (28.7) 555 (52.5) Outside target age group 11 (3.3) 74 (7.0) (missing) (0) (0) Last cytology result, n(%) Normal 242 (72.5) 513 (48.5) <0.0001 Abnormal 9 (2.7) 21 (2.0) No prior cytology obtained 83 (24.9) 524 (49.5) HPV vaccination prior to inclusion, n(%) Yes (4-valent HPV vaccine) 4 (1.2) - NA Yes (2-valent HPV vaccine) 0 (0) Yes (do not know name of vaccine) 1 (0.3) No 329 (98.5) (missing) (0) IDU intravenous drug user, NA not applicable, HAART Highly active antiretroviral therapy, HPV Human papillomavirus a b There was no difference in distribution of race between groups if the category “other” was removed from the “Race” variable (p = 0.45), No information c d available, As recommended in women living with HIV (we studied the past year + a 3-month grace period), As recommended in the general population, where women aged 23–49 years were invited for cervical cancer screening every third year and women aged 50–65 years every fifth year (we studied the past 3/5 years + a 3-month grace period) protection from the 9-valent HPV vaccine based upon WLWH had a higher risk of HPV58 and 56 compared their HPV genotype distribution (p= 0.14) (Table 2). with WGP (p < 0.0001 and p = 0.0023) (Fig. 3), while no significant differences in hrHPV genotype distribution HPV genotype distribution were found between White and Asian WLWH com- Figure 3 shows the prevalence of hrHPV genotypes with pared with WGP (Fig. 3). respect to race: i) overall, ii) in WLWH and WGP with normal cytological findings, and iii) WLWH and WGP HPV genotype distribution in women with normal with ASCUS+. Overall, the six most frequent high-risk cytology genotypes in WLWH were HPV58 (n = 21, 7.1 %), 52 In women with normal cytology the hrHPV preva- (n = 16, 5.4 %), 16 (n = 14, 4.8 %), 51 (n = 12, 4.1 %), lence was 22.0 % in WLWH versus 13.0 % in WGP 18 (n = 10, 3.4 %) and 33 (n =10, 3.4 %) versus 16 (n =60, (p = 0.0004). HPV58 (n = 13, 5.1 %), 52 (n =11, 4.3 %), 4.1 %), 52 (n = 41, 2.8 %), 58 (n = 35, 2.4 %), 31 (n =32, 51 (n = 8, 3.1 %) versus HPV16 (n = 49, 3.5 %), 58 (n =30, 2.2 %), 51 (n = 28, 1.9 %) and 33 (n = 26, 1.8) in WGP 2.2 %) and 52 (n = 30, 2.2 %) predominated in (Fig. 3, Additional file 1: Table S1). WLWH and WGP, respectively (Fig. 3, Additional file 2: Table S2). HPV genotype distribution according to race There was no difference in prevalence of hrHPV in HPV genotype distribution in women presenting with WLWH of White, Asian and Black race (26.6 %, 16.2 % ASCUS+ and 29.0, (p = 0.30)). We compared genotype distribution In WLWH and WGP with ASCUS+ 61.8 % versus in WLWH of different races and found that Black 49.0 % were hrHPV-positive (p = 0.25). Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 6 of 13 Fig. 1 Flowchart of women living with HIV (WLWH) from the SHADE cohort and women from the general population (WGP) from the Horizon study matched 1:5 on prior screening history and age Table 2 Prevalence of high-risk human papillomavirus (HPV) in women with sufficient DNA for analyses in women living with HIV compared to women matched (1:5) on prior screening history and age from the general Danish population Women living with HIV Women from the general population p-value 295 1,475 High-risk HPV positive, n(%) Yes 78 (26.4) 245 (16.6) <0.0001 No 217 (73.6) 1,230 (83.4) Number of genotypes, mean (range) 1.54 (1–4) 1.38 (1–5) 0.047 Number of infections, n(%) Single 48 (61.5) 182 (74.3) 0.030 Multiple (>1) 30 (38.5) 63 (25.7) All high-risk genotypes present targeted by the 4-valent HPV vaccine , n(% of the HPV positive patients) Yes 8 (10.3) 52 (21.2) 0.030 No 70 (89.7) 193 (78.8) All high-risk genotypes present targeted by the 9-valent vaccine , n(% of the HPV positive patients) Yes 42 (53.9) 155 (63.3) 0.14 No 36 (46.1) 90 (36.7) Presence of ≥1 high-risk genotypes targeted by the 4-valent vaccine , n(% of the HPV positive patients) Yes 21 (26.9) 76 (31.0) 0.49 No 57 (73.1) 169 (69.0) Presence of ≥1 high-risk genotypes targeted by the 9-valent vaccine , n(% of the HPV positive patients) Yes 61 (78.2) 194 (79.2) 0.85 No 17 (21.8) 51 (20.8) Targeting HPV6, HPV11, HPV16 and HPV18. HPV6 and HPV11 are low-risk genotypes and not included in this analysis Targeting HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58. HPV6, and HPV11 are low-risk genotypes and not included in this analysis Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 7 of 13 Fig. 2 Prevalence of high-risk human papillomavirus (HPV) according to age group in women living with HIV (WLWH) and women from the general population (WGP) Distribution of genotypes in descending order in Predictors of cytological abnormalities WLWH and WGP presenting with ASCUS+ were HPV58 HrHPV predicted ASCUS+ (adjusted OR 6.91 (95 % CI (n=8,23.5%), 16 (n = 7, 20.6 %) and 56 (n=5,14.7%) 2.91-16.42)) (Additional file 4: Table S4). However, in versus HPV52 (n = 11, 14.1 %), 16 (n = 10, 12.8 %) and 45 the subgroup of WLWH with hrHPV short duration of (n = 9, 11.5 %) (Fig. 3, Additional file 3: Table S3). HAART predicted ASCUS+ (adjusted OR 0.83 (95 % CI 0.71-0.97)) (Additional file 5: Table S5). Predictors of HPV In all adjusted analyses we checked the effect of miss- Short duration of HAART (adjusted OR per year 0.90 (95 ing values on outcome by adding an extra category with % CI 0.84-0.96)), AIDS prior to inclusion (adjusted OR missing values. This had no impact on the estimates. 3.61 (95 % CI 1.75-7.46)), ≥5 lifetime sexual partners (adjusted OR 2.20 (95 % CI 1.08-4.49)), sexual debut Discussion <16 years of age (adjusted OR 2.05 (95 % CI 1.03-4.10)) In this multicentre, cross-sectional cohort study of and CD4 < 350 cells/μL(adjusted OR 2.53 (95%CI WLWH in Denmark, we found a higher prevalence of cer- 1.20-5.40)) predicted prevalent hrHPV (Table 3). vical hrHPV in WLWH compared with WGP matched on prior screening history and age. Further, WLWH had a Cervical cytological abnormalities higher number of hrHPV genotypes and more carried Five (1.5 %) of the 332 cytology samples received from multiple hrHPV infections. Presence of ≥1 genotypes WLWH were inadequate for evaluation leaving 327 for in- covered by the 9-valent HPV vaccine was higher in terpretation. These were matched with cytology results WLWH and a higher number of WGP had all present from 1635 WGP (Fig. 1). ASCUS+ was prevalent in 34 genotypes covered by the 4-valent HPV vaccine. (10.4 %) versus 85 (5.2 %) WLWH and WGP, (p = 0.0003). WLWH had a different distribution of hrHPV genotypes Cytological abnormalities in WLWH and WGP were and this difference was mainly attributed to WLWH of distributed as follows: ASCUS: 8 (2.5 %) versus 42 (2.6 %), Black race. There was a higher risk of ASCUS+ in (p = 0.90); LSIL: 20 (6.1 %) versus 23 (1.4 %), (p < 0.0001) WLWH, due to a higher prevalence of LSIL. Finally, cer- and HSIL: 6 (1.8 %) versus 20 (1.2 %), (p =0.38). No vical HPV and ASCUS+ were predicted by short duration WLWH or WGP presented with carcinoma. of HAART. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 8 of 13 Fig. 3 (See legend on next page.) Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 9 of 13 (See figure on previous page.) Fig. 3 Cervical high-risk human papillomavirus (HPV) genotype distribution in women living with HIV (WLWH) compared to women from the general population (WGP); i) overall, ii) in women with normal cervical cytology, and iii) women with atypical cells of undetermined significance (ASCUS) or worse. Distribution is presented i) overall, ii) comparing WGP to WLWH of White race, iii) comparing WGP to WLWH of Black race and iv) comparing WGP to WLWH of Asian race. Please notice the different scale on the y-axis in the “ASCUS or worse” plots HPV prevalence with HIV infection probably contribute to the HPV Prevalent HPV infection is dependent on age with a pathogenesis by preventing spontaneous clearance of peak prevalence in women in the early 20s followed by a HPV [6]. A recent study found that in WLWH every steady decline and a second, but smaller peak in women month on HAART reduced the detection risk of any ≥45 years of age attributed to either new acquisition or cervical HPV infection by 9 % [30]. Likewise, short viral persistence [2, 14]. Therefore, we chose to match duration of HAART predicted HPV in the current WLWH and WGP on age and prior cytology/histology study. Moreover, sexual behavior such as early sexual results. The overall hrHPV prevalence in WLWH of debut and ≥5 lifetime sexual partners predicted preva- 26.4 % was lower than the hrHPV prevalence found in lent HPV and so did variables associated with a com- the European MACH-1 collaborative group of WLWH promised immune system such as CD4 < 350 cells/μL with a prevalence close to 50 % [15], however partici- and AIDS prior to inclusion. pants in the MACH study were younger (median age: 35 versus 42.5 years), less likely to be on HAART (69.7 % Cytological abnormalities versus 94.9 %) and a different assay (Hybrid Capture II) Overall, WLWH had more cytological abnormalities, was used for HPV detection. On a global scale the high- due to a higher prevalence of LSIL. A higher prevalence est prevalence of HPV in WGP with normal cytological of LSIL, but not ASCUS and HSIL, in WLWH is also findings is found in Africa (24 %) [14]. Though, the over- reported by others [35]. Most LSILs are transient and all hrHPV prevalence was highest in WLWH of Black resolve within 1–2 years [36], and are most often not race, this difference was not significant. treated according to current Danish guidelines. A high proportion of WLWH included and not included in the HPV genotype distribution study; 28.7 % and 52.5 %, had not been screened for CC Studies of WGP across all continents have repeatedly in the preceding 3 to 5 years. We have previously identified hrHPV16 and 18 - accounting for about 70 % assessed low screening attendance in this cohort of of all CCs [2, 6] – to be among the most prevalent [8]. WLWH and support the idea of cytology as part of an In agreement with others we found HPV58 and 52 to be annual medical HIV review, integration of HIV care and prevailing in WLWH [8, 16]. Though, the numbers were cervical screening in a single clinic setting and targeted small, this higher risk of HPV58 was mainly carried by public health messages aimed at health care profes- women of Black race, as no significant difference in sionals at HIV centres, general practitioners and WLWH genotype distribution, was detected when comparing [37]. However, the low screening attendance does not WGP with WLWH of White and Asian race. While the explain differences in cytological abnormalities between 2-and 4-valent HPV vaccines are anticipated to reduce WLWH and WGP, since women were matched on prior the burden of HPV-related cancers in WGP [13], the screening history. impact of these HPV vaccines in WLWH is less clear. More than 20 % of WGP had all genotypes present Predictors of cervical dysplasia covered by the 4-valent HPV vaccine, whereas only Predictors of cervical dysplasia and CC are those also one-tenth of genotypes were accounted for amongst associated with HPV infection such as smoking, early WLWH. The novel 9-valent HPV-vaccine targeting sexual debut, number of lifetime sexual partners, hormo- HPV6, 11, 16, 18, 31, 33, 45, 52, and 58 has the po- nal contraceptives and STDs other than HPV [6, 7]. We tential to prevent about 90 % of CC cases in WGP if have earlier reported that only a very few of WLWH in administered before sexual onset [33] might be better SHADE presented with STDs other than HPV [23] and suited for the HIV population. therefore this variable was not adjusted for. Not surpris- ingly, hrHPV predicted ASCUS+. Since hrHPV causes Predictors of HPV most cases of dysplasia and basically all cases of CC [6], The molecular mechanisms leading to the increased this variable could blur the effect of other covariates. We risk of HPV in PLHIV are poorly understood [34]. therefore performed a sensitivity analysis in WLWH Tugizov et al. suggested that HIV-proteins enable ini- with hrHPV, and in consistence with our findings tial HPV infection by disrupting the epithelial tight regarding HPV we found that short duration of HAART junctions [34]. Moreover, immune defects associated predicted ASCUS+. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 10 of 13 Table 3 Unadjusted and adjusted odds ratios for predictors of cervical high-risk human papillomavirus (HPV) infection in women living with HIV with sufficient DNA for HPV analysis (n = 295) a b Predictors of HPV HPV-positive group HPV-negative group Unadjusted odds ratios p-value Adjusted odds ratios p-value (n = 78) (n = 151) Age at 1 February 2011 (inclusion), n(%) 18-29 years 9 (11.5) 9 (4.2) 1.00 - 1.00 - 30-50 years 51 (65.4) 161 (74.2) 0.32 (0.12-0.84) 0.02 0.43 (0.14-1.33) 0.14 > 50 years 18 (23.1) 47 (21.7) 0.38 (0.13-1.12) 0.08 0.51 (0.13-1.92) 0.32 (missing) 0 (0) (0) Combined p-value 0.068 0.32 Race, n(%) White 34 (44.7) 94 (44.1) 1.00 - 1.00 - Asian 6 (7.9) 31 (14.6) 0.54 (0.21-1.40) 0.20 0.67 (0.23-1.92) 0.46 Black 36 (47.4) 88 (41.3) 1.13 (0.65-1.96) 0.66 0.38 (0.67-2.87) 0.38 (missing) (2) (4) - - Combined p-value 0.31 0.35 Sexual debut, n(%) ≥ 16 years of age 51 (65.4) 160 (73.7) 1.00 - 1.00 - < 16 years of age 27 (34.6) 57 (26.3) 1.49 (0.85-2.59) 0.16 2.05 (1.03-4.10) 0.042 (missing) (0) (0) - HAART duration, (years) Median (IQR) 4.6 (2.0-10.4) 8.8 (4.6-12.2) 0.91 (0.86-0.96) 0.0013 0.90 (0.84-0.96) 0.0011 (missing) (2) (9) AIDS prior to inclusion, n(%) No 55 (71.4) 191 (88.4) 1.00 - 1.00 - Yes 22 (28.6) 25 (11.6) 0.33 (0.17-0.63) 0.0007 3.61 (1.75-7.46) 0.0005 (missing) (1) (1) Smoking status, n(%) Current smoker/Ex-smoker 33 (42.3) 92 (42.4) 1.00 - 1.00 - Never smoker 45 (57.7) 125 (57.6) 1.00 (0.59-1.69) 0.99 1.31 (0.65-2.63) 0.45 (missing) (0) (0) Number of lifetime sexual partners at inclusion, n(%) < 5 36 (25.0) 54 (36.0) 1.00 - 1.00 - ≥ 5 108 (75.0) 96 (64.0) 1.83 (1.00-3.36) 0.05 2.20 (1.08-4.49) 0.03 (missing) (0) (1) Use of hormonal contraceptives, n(%) 12 (8.3) 9 (6.0) 1.00 - 1.00 - Yes 132 (91.7) 142 (94.0) 0.89 (0.33-2.38) 0.82 1.29 (0.40-4.10) 0.67 No (0) (0) (missing) CD4 count at inclusion (cells/μL), > 350 45 (69.2) 173 (83.2) 1.00 - 1.00 - 200-350 15 (23.1) 28 (13.5) 2.06 (1.02-4.18) 0.045 2.53 (1.20-5.40) 0.015 < 200 5 (7.7) 7 (3.4) 2.75 (0.83-9.06) 0.10 2.70 (0.78-9.33) 0.12 (missing) (13) (9) Combined p-value 0.0496 0.023 HAART = Highly active antiretroviral therapy Two models are shown in the table: Age, race, sexual debut, smoking status, number of lifetime sexual partners and use of hormonal contraceptives were included in both models, whereas HAART duration and AIDS prior to inclusion were included in the first model and replaced by CD4 at inclusion inthe second model, We only presented the ORs of the CD4 count from the second model, The validity of the model was tested using the Hosmer and Lemeshow Goodness-of-Fit Test Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 11 of 13 Strengths and limitations MSM: Men who have sex with men; OR: Odds ratio; PIN: Personal identification number; PLHIV: People living with HIV; SHADE: Study on HIV, We have a very well-described cohort due to the DHCS cervical Abnormalities and infections in women in Denmark; STD: Sexually and DPDB and were able to match on prior cytological transmitted diseases; WGP: Women from the general population; outcomes. Compared to other Western countries Danish WLWH: Women living with HIV women represent a CC high-risk population [18], there- fore comparison to WGP is essential in interpretation of Acknowledgements We are first and foremost grateful to all the women living with HIV for results. participating in the study. We further thank the staff of our clinical Possible limitations are that WLWH included in departments for their continuous support and enthusiasm at the SHADE were more likely to comply with CC screening participating centres in the SHADE cohort: Department of Infectious Diseases, Hvidovre, Copenhagen University Hospital (AM Lebech, K programs and to have a previous normal cytology result. Thorsteinsson); Department of Infectious Diseases, Copenhagen University Therefore estimates regarding cytological abnormalities Hospitals, Rigshospitalet (TL Katzenstein, FF Rönsholt); Department of in WLWH might be conservative. The effect of HAART Infectious Diseases, Odense University Hospital (IS Johansen); Department of Infectious Diseases, Aarhus University Hospitals, Skejby (M Storgaard); duration can be confounded by other time-scales such Department of Infectious Diseases, Aalborg University Hospital (G Pedersen); as duration of HIV. Moreover, racial origin of the WGP Department of Infectious Diseases, Hillerød Hospital (LN Nielsen). Moreover, group was not available for direct comparison to the we are grateful to the study group behind the Horizon Study for providing us with data on women from the general population. SHADE cohort. Furthermore, a higher number of inad- equate HPV samples were collected in the present study Funding compared to ordinary CC screening samples included in This work was supported by the Danish Cancer Society and the AIDS the Horizon study, probably as a consequence of sam- Foundation; the Aragon Foundation; the Foundation of Aase and Ejnar pling by personnel less trained in gynecological routines. Danielsens and the Foundation of Anna and Preben Simonsen. Grant numbers do not apply in a Danish setting. The sponsors of the study had no Finally, this is a cross-sectional study giving information role in study design, data collection, data analysis, data interpretation or on HPV infection at the time of one single sampling. writing of the article. The limitation in this design is that without previous or subsequent sampling results, any HPV infection ob- Availability of data and materials served may be a transient infection. We believe that all data of relevance for the present study is available within the manuscript and in the Additional file 1: Table S1, Additional file 2: Table S2, Additional file 3: Table S3, Additional file 4: Table S4 and Additional file 5: Conclusions Table S5. We are open to collaboration and in involving other researchers in our work. However, we strongly feel that we cannot make a full dataset WLWH had a higher risk of being cervical hrHPV posi- publicly available for the following reasons: We are extremely concerned tive, a higher frequency of multiple infections, a different about confidentiality – since these patients may be identified by genotype distribution and more cytological abnormalities combinations of person-specific characteristics within the database, and the database includes sensitive data such as HIV status, previous diagnosis of than WGP. Cervical HPV and ASCUS+ were predicted by AIDS, data on intravenous drug use and sexual preferences. Further we are short duration of HAART. concerned that public access to our dataset would compromise our ability to publish future articles on WLWH included in the SHADE. Additional files Authors’ contributions Additional file 1: Table S1. Comparison of the overall prevalence KT contributed to conception and design of the study, included patients, of high-risk HPV genotypes in women living with HIV (WLWH) and performed interviews and gynaecological examinations, analysed and age-matched women from the general population (WGP). (DOCX 20 kb) interpreted data, and drafted the manuscript. SL, biostatistician, was involved in analysis and interpretation of data, and critically reviewed the manuscript. Additional file 2: Table S2. Comparison of the prevalence of high-risk MS contributed to conception and design of the study, included patients, HPV genotypes in women living with HIV (WLWH) and women from the performed interviews and gynaecological examinations, and critically general population (WGP) with normal cytological findings. (DOCX 20 kb) reviewed the manuscript. TLK contributed to conception and design of the Additional file 3: Table S3. Comparison of the prevalence of high-risk study, included patients, performed interviews and gynaecological HPV genotypes in women living with HIV (WLWH) and women from the examinations, and critically reviewed the manuscript. FR included patients, general population (WGP) with abnormal cytological findings (ASCUS or performed interviews and gynaecological examinations, and critically worse). (DOCX 20 kb) reviewed the manuscript. ISJ contributed to conception and design of the Additional file 4: Table S4. Unadjusted and adjusted odds ratios for study, included patients, performed interviews and gynaecological predictors of ASCUS or worse (ASCUS+) in women living with HIV with examinations, and critically reviewed the manuscript. GP included patients, adequate cytology samples. (DOCX 27 kb) performed interviews, and critically reviewed the manuscript. LH, performed gynaecological examinations and critically reviewed the manuscript. LNN Additional file 5: Table S5. Unadjusted and adjusted odds ratios included patients and performed interviews, and critically reviewed the for predictors of ASCUS or worse in women living with HIV with manuscript. LN, performed gynaecological examinations in WLWH needing adequate cytology samples and positive for cervical high-risk human follow-up and provided valuable information on gynaecological procedures papillomavirus. (DOCX 26 kb) in Denmark, and critically reviewed the manuscript. JB was in charge of the analyses of HPV, and critically reviewed the manuscript. NO, head of the Abbreviations DHCS, critically reviewed the manuscript. AML, principal investigator, CC: Cervical cancer; CI: Confidence interval; CRS: Civil Registration System; contributed to conception and design of the study, included patients and DF: Degrees of freedom; DHCS: Danish HIV Cohort Study; DPDB: The Danish performed interviews and gynaecological examinations, was involved in Pathology Data Bank; HAART: Highly active antiretroviral therapy; analysis and interpretation of data, and critically reviewed the manuscript. HPV: Human papillomavirus; HVH: Hvidovre, Copenhagen University Hospital; All authors read and approved the final manuscript. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 12 of 13 Competing interests 7. Rocha-Brischiliari SC, Gimenes F, de Abreu AL, Irie MM, Souza RP, Santana KT has received research funding from Abbott and honoraria from Janssen- RG, et al. Risk factors for cervical HPV infection and genotypes distribution Cilag, BMS and GlaxoSmithKline/Viiv. JB has in the past served as paid advisor in HIV-infected South Brazilian women. Infect Agent Cancer. 2014;9:6. or advisory board member to Roche Molecular Systems, Genomica SAU, and 8. McKenzie ND, Kobetz EN, Hnatyszyn J, Twiggs LB, Lucci III JA. Women with BD Diagnostics. He has received honoraria from Roche, Qiagen, Hologic, HIV are more commonly infected with non-16 and −18 high-risk HPV types. Genomica and Bd Diagnostics for lectures. HW has received research Gynecol Oncol. 2010;116:572–7. funding and honoraria from Roche Molecular, Hologic, and Novo Nordic. 9. Denslow SA, Rositch AF, Firnhaber C, Ting J, Smith JS. Incidence and TLK has received research funding and/or honoraria from Bristol-Myers progression of cervical lesions in women with HIV: a systematic global Squibb, Merck Sharp & Dohme, GlaxoSmithKline/Viiv, Abbott, Gilead, review. Int J STD AIDS. 2014;25:163–77. and Janssen-Cilag. AML has received research funding from Abbott 10. Ogembo RK, Gona PN, Seymour AJ, Park HS, Bain PA, Maranda L, et al. and honoraria from Bristol-Myers Squibb, Merck Sharp & Dohme, Prevalence of human papillomavirus genotypes among African women GlaxoSmithKline, Boehringer Ingelheim and Janssen-Cilag. SL, MS, with normal cervical cytology and neoplasia: a systematic review and FR, IJ, LH, LNN, LN and NO report no conflicts of interest. meta-analysis. PLoS One. 2015;10:e0122488. 11. Bonde J, Rebolj M, Ejegod DM, Preisler S, Lynge E, Rygaard C. HPV Consent to publish prevalence and genotype distribution in a population-based split-sample Not applicable. study of well-screened women using CLART HPV2 human papillomavirus genotype microarray system. BMC Infect Dis. 2014;14:413–4. doi:10.1186/ 1471-2334-14-413. Ethics approval and consent to participate 12. Kjaer SK, Munk C, Junge J, Iftner T. Carcinogenic HPV prevalence and At entry, written and oral informed consent was obtained from all age-specific type distribution in 40,382 women with normal cervical participants. The study and the DHCS were approved by the Danish Data cytology, ASCUS/LSIL, HSIL, or cervical cancer: what is the potential for Protection Agency (2015-231-0126, 2012-58-0004 and 2012-41-0005). Further, prevention? Cancer Causes Control. 2014;25:179–89. the study was approved by the Danish Regional Committee on Health 13. Saraiya M, Unger ER, Thompson TD, Lynch CF, Hernandez BY, Lyu CW et al. Research Ethics (approval numbers: H-3-2010-119 and H-2-2014-102). US Assessment of HPV Types in Cancers: Implications for Current and 9- Valent HPV Vaccines. J Natl Cancer Inst. 2015;107(6). Meetings where the work has been presented 14. Bruni L, Diaz M, Castellsague X, Ferrer E, Bosch FX, de SS. Cervical human Oral at the 15th European AIDS Conference in Barcelona, Spain, October nd papillomavirus prevalence in 5 continents: meta-analysis of 1 million 21–24, 2015. Oral at the 2 Nordic HIV & Women Meeting, Copenhagen, women with normal cytological findings. J Infect Dis. 2010;202:1789–99. December 9, 2015. 15. Heard I, Cubie HA, Mesher D, Sasieni P. Characteristics of HPV infection over time in European women who are HIV-1 positive. BJOG. 2013;120:41–9. Author details 16. Heard I. Human papillomavirus, cancer and vaccination. Curr Opin HIV AIDS. Department of Infectious Diseases, Hvidovre, Copenhagen University 2011;6:297–302. Hospital, Copenhagen, Denmark. Department of Infectious Diseases, Skejby, 17. Obel N, Omland LH, Kronborg G, Larsen CS, Pedersen C, Pedersen G, Aarhus University Hospital, Aarhus, Denmark. Department of Infectious et al. Impact of non-HIV and HIV risk factors on survival in HIV-infected Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, patients on HAART: a population-based nationwide cohort study. PLoS Denmark. Institute of Clinical Medicine, University of Copenhagen, One. 2011;6:e22698. Copenhagen, Denmark. Clinical Research Center, Hvidovre, Copenhagen 18. Nygard M, Hansen BT, Dillner J, Munk C, Oddsson K, Tryggvadottir L, et al. University Hospital, Copenhagen, Denmark. Department of Infectious Targeting human papillomavirus to reduce the burden of cervical, vulvar Diseases, Odense University Hospital, Odense, Denmark. Department of and vaginal cancer and pre-invasive neoplasia: establishing the baseline for Infectious Diseases, Aalborg University Hospital, Aalborg, Denmark. surveillance. PLoS One. 2014;9:e88323. Department of Obstetrics and Gynaecology, Aalborg University Hospital, Aalborg, Denmark. Department of Infectious Diseases, Nordsjællands 19. Kjaer SK, Breugelmans G, Munk C, Junge J, Watson M, Iftner T. Population- Hospital, Hillerød, Denmark. Department of Obstetrics and Gynaecology, based prevalence, type- and age-specific distribution of HPV in women Hvidovre, Copenhagen University Hospital, Copenhagen, Denmark. before introduction of an HPV-vaccination program in Denmark. Int Molecular Pathology Laboratory, Department of Pathology, Hvidovre, J Cancer. 2008;123:1864–70. Copenhagen University Hospital, Copenhagen, Denmark. Department of 20. http://www.dst.dk/da/Statistik/emner/befolkning-og-befolkningsfremskrivning/ Infectious Diseases, Hvidovre Hospital, Kettegaards Allé 30, 2650 Hvidovre, folketal.aspx. Accessed on 14 Sept 2012. Webpage in Danish. 14-9-2012. Ref Denmark. Type: Internet Communication 21. http://www.ssi.dk/Service/Sygdomsleksikon/H/AIDS%20-%20HIV.aspx. Received: 24 May 2016 Accepted: 24 October 2016 Accessed on September 14th 2012. Webpage in Danish. 14 Sept 2012. Ref Type: Internet Communication 22. Obel N, Engsig FN, Rasmussen LD, Larsen MV, Omland LH, Sorensen HT. Cohort profile: the Danish HIV cohort study. Int J Epidemiol. 2009;38:1202–6. References 23. Thorsteinsson K, Ladelund S, Storgaard M, Ronsholt FF, Johansen IS, 1. Markowitz LE, Dunne EF, Saraiya M, Chesson HW, Curtis CR, Gee J, et al. Pedersen G, et al. Sexually transmitted infections and use of contraceptives Human papillomavirus vaccination: recommendations of the Advisory in women living with HIV in Denmark - the SHADE cohort. BMC Infect Dis. Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2016;16:81. 2014;63:1–30. 24. Screening of cervical cancer - recommendations 2007. The Danish National 2. Juckett G, Hartman-Adams H. Human papillomavirus: clinical manifestations Board of Health. Available from: http://sundhedsstyrelsen.dk/publ/Publ2007/ and prevention. Am Fam Physician. 2010;82:1209–13. PLAN/Kraeft/Anbef_screen_livmoderhals.pdf. Article in Danish. Summary in 3. Walboomers JM, Jacobs MV, Manos MM, Bosch FX, Kummer JA, Shah KV, English. Accessed on 22nd May 2015. 22-5-2015. 22-5-2015. Ref Type: et al. Human papillomavirus is a necessary cause of invasive cervical cancer Internet Communication worldwide. J Pathol. 1999;189:12–9. 25. Kaplan JE, Benson C, Holmes KH, Brooks JT, Pau A, Masur H. Guidelines for 4. Cervical Cancer. Estimated Incidence, Mortality and Prevalence Worldwide prevention and treatment of opportunistic infections in HIV-infected adults in 2012. Globocan 2012. WHO. http://globocan.iarc.fr/old/FactSheets/ and adolescents: recommendations from CDC, the National Institutes of cancers/cervix-new.asp. Accessed on 21 Dec 2015. 21-12-2015. 21-12-2015. Health, and the HIV Medicine Association of the Infectious Diseases Society Ref Type: Internet Communication. of America. MMWR Recomm Rep. 2009;58:1–207. 5. Chaturvedi AK, Madeleine MM, Biggar RJ, Engels EA. Risk of human papillomavirus-associated cancers among persons with AIDS. J Natl Cancer 26. Lauritsen JM & Bruus M. EpiData (version 3.1). A comprehensive tool for Inst. 2009;101:1120–30. validated entry and documentation of data. The EpiData Association, 6. Brickman C, Palefsky JM. Human papillomavirus in the HIV-infected host: Odense, Denmark, 2003–2005. 11-2-2015. Ref Type: Generic. epidemiology and pathogenesis in the antiretroviral Era. Curr HIV/AIDS 27. Pedersen CB. The Danish civil registration system. Scand J Public Health. Rep. 2015;12:6–15. 2011;39:22–5. Thorsteinsson et al. BMC Cancer (2016) 16:866 Page 13 of 13 28. Erichsen R, Lash TL, Hamilton-Dutoit SJ, Bjerregaard B, Vyberg M, Pedersen L. Existing data sources for clinical epidemiology: the Danish National Pathology Registry and Data Bank. Clin Epidemiol. 2010;2:51–6. 29. Solomon D, Davey D, Kurman R, Moriarty A, O'Connor D, Prey M, et al. The 2001 Bethesda System: terminology for reporting results of cervical cytology. JAMA. 2002;287:2114–9. 30. Zeier MD, Botha MH, Engelbrecht S, Machekano RN, Jacobs GB, Isaacs S, et al. Combination antiretroviral therapy reduces the detection risk of cervical human papilloma virus infection in women living with HIV. AIDS. 2015;29:59–66. 31. Marks MA, Gupta S, Liaw KL, Tadesse A, Kim E, Phongnarisorn C, et al. Prevalence and correlates of HPV among women attending family-planning clinics in Thailand. BMC Infect Dis. 2015;15:159. 32. R Core Team (2015). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http:// www.R-project.org/. Accessed 24 June 2015. 24-6-2015. 24-6-2015. Ref Type: Internet Communication 33. Serrano B, Alemany L, Tous S, Bruni L, Clifford GM, Weiss T, et al. Potential impact of a nine-valent vaccine in human papillomavirus related cervical disease. Infect Agent Cancer. 2012;7:38. 34. Tugizov SM, Herrera R, Chin-Hong P, Veluppillai P, Greenspan D, Michael BJ, et al. HIV-associated disruption of mucosal epithelium facilitates paracellular penetration by human papillomavirus. Virology. 2013;446:378–88. 35. Micheletti AM, Dutra VF, Murta EF, Paschoini MC, Silva-Vergara ML, Barbosa e Silva, et al. Cervicovaginal cytological abnormalities in patients with human immunodeficiency virus infection, in relation to disease stage, CD4 cell count and viral load. Diagn Cytopathol. 2009;37:164–9. 36. Rodriguez AC, Schiffman M, Herrero R, Wacholder S, Hildesheim A, Castle PE, et al. Rapid clearance of human papillomavirus and implications for clinical focus on persistent infections. J Natl Cancer Inst. 2008;100:513–7. 37. Thorsteinsson K, Ladelund S, Jensen-Fangel S, Katzenstein TL, Johansen IS, Pedersen G, et al. Adherence to the cervical cancer screening program in women living with HIV in Denmark: comparison with the general population. BMC Infect Dis. 2014;14:256. 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