Human papillomavirus correlates of high grade cervical dysplasia among HIV-Infected women at a major treatment centre in Nigeria: a cross-sectional study

Introduction Persistent high-risk HPV (hrHPV) infection is higher among women living with HIV/AIDS thus increasing their risk for cervical cancer. We evaluated the virological and immunological correlates of cervical dysplasia in HIV-infected women. Methods A cohort of 220 consenting women attending the antiretroviral clinic of the Federal Medical Centre, Keffi, Nigeria was tested for cervical human papilloma virus (HPV) infection using PCR. The prevalent HPV genotypes were determined by DNA sequencing. CD4+T count and type specific HPV was correlated with cervical cytology. Descriptive and inferential statistical analysis of the data was done using the statistical package for social sciences (SPSS) version 20 (SPSS Inc, Illinois, USA) for analysis after validation Results Overall HPV prevalence was 54.1% while the hrHPV prevalence was 35.9%. Premalignant and malignant lesions were observed among participants with CD4+T counts between 200-300/mm3. A statistically significant association was observed between cervical premalignant lesions and CD4+ count (X2=24.747, P value=0.001) as well as hrHPV infections (X2=46.800, P<0.001). Conclusion Risk stratification with HPV screening among HIV-infected women will help in early case management of cervical precancerous lesions.


Introduction
Human papilloma virus (HPV) is the most common sexually transmitted pathogen in humans and has been implicated in the aetiology of cervical, oropharyngeal and other anogenital cancers [1,2]. More than 100 HPV genotypes have been characterized and classified based on their oncogenic potential into high-risk HPV (hrHPV) and low-risk HPV (lrHPV) genotypes [1,3,4]. Persistent high risk HPV infection is necessary but requires additional co-factors to cause both malignant and premalignant cervical lesions [1]. The immunosuppressive state induced by Human Immunodeficiency Virus (HIV) potentially increases HPV acquisition, persistence, and development of cervical cancer [2]. Globally, an increased risk of HPV infection and cervical squamous intraepithelial lesions (SIL) has been reported among HIV-positive women [2,[5][6][7]. Previous studies among HIV-positive women have reported increased multiple infections with varied hrHPV genotypes [1,2,8]. Although cancer of the uterine cervix is the commonest genital tract malignancy in Northern Nigeria, only a few studies have reported the prevalence of type-specific HPV among HIV-infected women [9,10]. We have previously reported a high burden of HPV 16

Study area and population
The study was carried out at the antiretroviral clinic of Federal Medical

Specimen collection and storage
Rovers ® Cervex-Brush ® cell sampling device (Rovers Medical Devices B.V 5347 KV Oss, The Netherlands) and liquid based cytological processing and preservative reagent (Zeni-Prep ® , Zenith diagnostics, USA) were used for specimen collection and transport. Specimen was obtained by inserting the cytobrush into the cervical canal and rotating it four times to collect all the cervical epithelial cells which adhered to the flat sides of the bristles. The brush was then transferred into the vial containing preservative fluid.

Papanicolaou smear
Cervical smears obtained from each participant was stained using the standard papanicolaou's method in order to assess the presence of cervical premalignant/malignant lesions which was rated according to the 2001 Bethesda system of classification by a cytopathologist.

DNA extraction
HPV testing was done at the DNA Labs, Kaduna, Nigeria. Gel extraction prior to DNA purification for sequencing was done using QIAquick Gel Extraction Kit (QIAGEN Sample & Assay Technologies, Germany). Briefly, HPV DNA was extracted from exfoliated cervical cells using proteinase K-based digestion protocol. Cells were incubated with proteinase K solution (100 µg/ml) for three hours at 55°C. DNA was then further purified by spin column chromatography.

Data analysis
Descriptive and inferential statistical analysis of the data was done  were unemployed and were housewives, while 66 (30%) were selfemployed and the remaining 33 (15%) were employed either in the public or private sector. Majority of the participants 215 (97.7%) were already on HAART while the others were treatment naive.

Analysis of HPV Infection
Overall, HPV DNA was detected in 119 (54.1%) of the participants while high-risk HPV types were detected in 79 (35.9%) samples.
HPV 35 was the most frequent 12 (20.5%), with multiple HPV infections seen in 25 (21.0%) samples. Other observed genotypes are listed in Table 1.

Association between CD4+ count and hrHPV infection
CD4+T counts estimated within six months of sample collection were available for 193 (87.7%) of the participants. Although majority, 91 (47.2%) had CD4+ T values greater than 500 cells/mm 3 , there was no significant statistical association between CD4+T counts and hrHPV infection.

Conclusion
The current study highlights high hrHPV prevalence of 35.  The study therefore justified the need for routine targeted screening and treatment of HIV-infected women to reduce morbidity and mortality from cervical cancer.

Competing interests
The authors declare no competing interests.

Acknowledgements
We  Table 1: frequency distribution of HPV Genotypes among the participants Table 2: association between CD4+ count and cervical cytology