COMPARISON OF SELF-OBTAINED AND PHYSICIAN-OBTAINED CERVICAL SWAB SAMPLES FOR DETECTION OF HUMAN PAPILLOMAVIRUS (HPV) DNA IN WOMEN INFECTED WITH HIV

F Coutlée, C Hankins, S Walmsley, D Money, K Pourreaux, P Forest, J-O Shu, Canadian Women’s HIV Study Group
Centre Hospitalier de l’Université de Montréal; Direction de la santé publique de Montréal; Department of Epidemiology and Biostatistics, McGill University; Toronto General Hospital, Toronto; Oak Tree Clinic, Vancouver

Background: HPV causes precancerous and cancerous cervical lesions in HIV-infected women. Standard HPV screening requires a gynaecological examination. Non-invasive sampling methods could facilitate screening for genital HPV infection.
Objectives: To compare self-obtained vaginal swab samples (SOVS) and cervical swab samples obtained by a physician (CSSP) for the detection and typing of HPV DNA in a cohort of HIV-infected women.
Methods: Paired swab samples obtained at the same visit were processed and tested for b-globin for specimen accuracy. b-globin-positive lysates were amplified for HPV DNA with PGMY09-PGMY11 and amplicons were typed for 27 HPV genotypes (18 high-risk and 9 low-risk) using the Line blot assay.
Results: Of 173 paired samples, one sample in each of 8 pairs tested negative for b-globin, leaving 165 pairs from 140 different women for comparison. Paired samples were obtained at 3 visits for 7 women, at 2 visits for 10 and at one visit for 123. The sensitivity and specificity of SOVS compared to CSSP for HPV DNA detection reached 97.8% (87 of 89 HPV-positive samples) and 72.4% (55 of 76 HPV-negative samples), respectively. Results from 142 (86.1%) paired samples were concordant for HPV DNA detection (Kappa value of 0.74). Considering only high-risk types, concordant results were obtained for 142 sample pairs (73 positive, 69 negative) and discordant results were obtained for 23 sample pairs (22 positive SOVS and 1 positive CSS) (Kappa of 0.73). Although a high level of concordance was obtained for HPV-16 and HPV-33 (93.7% and 100%, respectively), results for some important high risk types were less frequently concordant (58% for HPV-18, 20% for HPV-45).
Conclusions: Self-obtained vaginal samples demonstrate a high degree of sensitivity for the detection of HPV infection. The relationship between vaginal HPV detection and progression of cervical dysplasia in HIV infected women needs to be further studied.