Human papillomavirus type 16 lineage analysis based on E6 region in cervical samples of Iranian women

It is suggested that distinct HPV 16 variants differ in oncogenic potential and geographic distribution. As such, understanding the regional variants of HPV 16 would be of great importance for evolutionary, epidemiological and biological analysis. In this regard, the sequence variations of E6 gene were investigated to characterize more common variants of HPV 16 in normal cells, premalignant and malignant lesions of the cervix. In total, 106 isolates of HPV 16 were analyzed by PCR and sequencing. Overall, two different lineages (A and D) were identified. Lineage D comprised 70.7% of samples and the remaining 29.3% belonged to lineage A. Regarding to cytology/histology, lineage D was dominant in both normal + CIN I-II and CIN III + ICC groups as it was detected in 80% and 66.2% of cases, respectively. The comparison of the lineages between different groups (35 normal + CIN I-II samples and 71 CIN III + ICC samples) revealed that lineage A is more prevalent in cervical cancer cases (7 (20%) vs. 24 (33.8%)) although the difference observed did not reach statistical significance (p = 0.07). In conclusion, our findings confirm that HPV lineages A and D are more prevalent in Iran, with the lineage D as the most dominant in all studied groups.