Prevalence of human papilloma virus in cytological abnormalities: Association of risk factors and cytomorphological findings

Abstract

Background: Previous studies demonstrated the etiological role of human papilloma virus (HPV) in cervical carcinogenesis. Assessing the distribution of HPV may elucidate these observations. Materials and Methods: In total, we examined 3839 specimens, of which 187 abnormally classified cervical smears were immunostained using the p16 [sup]INK4A assay. DNA was extracted from 182 specimens, and polymerase chain reaction (PCR) was performed. Participants' socio-demographics, sexual and reproductive history, HIV status, contraceptive use, and Pap smear history were recorded. Results: Subject ages, number of sexual partners, and age at first sexual encounter ranged from 15 to 49 years, from 1 to 37 partners, and from 13 to 34 years, respectively. P16 immunoreactivity was detected in 60.4% of cases. The distribution of epithelial lesions and P16 overexpression (bracketed) was: 28 (5) atypical squamous cells of undetermined significance (ASC-US), 96 (50) lower grade squamous intraepithelial lesion (LSIL), 9 (7) atypical squamous cells-cannot exclude HSIL (ASC-H), and 54 (51) higher grade squamous intraepithelial lesion (HSIL). Ninety-four percent of HSIL expressed P16. Fifty-two percent of LSIL expressed P16. P16 expression declined from 61% (25-34 year age group) to 5% (45-49 year age group) for different age groups. HPV-DNA by PCR was detected in 94.5% of P16-positive samples. Type- specific PCR (HPV 16 and 18) was found in 12.2% and 14.5% of abnormal lesions, respectively. Younger age at first sexual encounter and HIV infection predominated in HPV type(s) 16 and/or 18 positive subjects. Conclusion: This study reinforced the value of the p16 [sup]INK4A surrogate marker in identifying women with progressive cervical disease