HPV genotype distribution in Brazilian women with and without cervical lesions: correlation to cytological data.

Background: Human Papillomavirus (HPV) genotype distribution varies according to the method of assessment and population groups. This study analyzed type-specific HPV infections among women ranging from 14-95 years old, displaying normal and abnormal cytology, from São Paulo and Barretos cities, Brazil.
Methods: Women found positive for High Risk-HPVs DNA by either the Hybrid Capture 2 (HC2) or Cobas HPV Test (n = 431) plus a random sample of 223 negative by both assays and 11 samples with indeterminate results, totalizing 665 samples, were submitted to HPV detection by the PapilloCheck test. Cytological distribution included 499 women with a cytological result of Negative for Intraepithelial Lesion or Malignancy and 166 with some abnormality as follows: 54 Atypical Squamous Cells of Undetermined Significance; 66 Low-Grade Squamous Intraepithelial Lesion; 43 High-Grade Squamous Intraepithelial Lesion and 3 (0.5 %) Invasive Cervical Cancer.
Results: From the 323 samples (48.6 %) that had detectable HPV-DNA by the PapilloCheck assay, 31 were HPV negative by the cobas HPV and HC2 assays. Out of these 31 samples, 14 were associated with HR-HPVs types while the remaining 17 harbored exclusively low-risk HPVs. In contrast, 49 samples positive by cobas HPV and HC 2 methods tested negative by the PapilloCheck assay (19.8 %). Overall, the most frequent HR-HPV type was HPV 16 (23.2 %), followed by 56 (21.0 %), 52 (8.7 %) and 31 (7.7 %) and the most frequent LR-HPV type was HPV 42 (12.1 %) followed by 6 (6.2 %). Among the HR-HPV types, HPV 56 and 16 were the most frequent types in NILM, found in 19.1 and 17.7 % of the patients respectively while in HSIL and ICC cases, HPV 16 was the predominant type, detected in 37.2 and 66.7 % of these samples.
Conclusions: In the population studied, HPV 16 and 56 were the most frequently detected HR-HPV types. HPV 56 was found mainly in LSIL and NILM suggesting a low oncogenic potential. HPV 16 continues to be the most prevalent type in high-grade lesions whereas HPV 18 was found in a low frequency both in NILM and abnormal smears. Surveillance of HPV infections by molecular methods is an important tool for the development and improvement of prevention strategies.