Variant sublineages of human papillomavirus type 16 predispose women to persistent infection characterized by a sequence analysis of the E6, L1, and LCR regions.

Background: One of the precursors of cervical cancer is persistent infection with human papillomavirus (HPV), especially high-risk HPV. The aim of this study was to verify the relationship between HPV16 variants and persistent viral infection.

Methods: Three-hundred and eighty-six Chinese women who had a low-grade squamous intraepithelial lesion (LSIL) or a lesion below LSIL with normal cellular morphology were selected and enrolled in this study. Flow-through hybridization and gene chip technology were applied to identify the HPV type, and a PCR-sequencing assay was performed to detect HPV16 E6, L1, and long control region (LCR) gene variants. The relationship between HPV16 variants and persistent infection was analyzed using Fisher's exact test.

Results: In this population, 74.09% of HPV16 isolates belonged to the A4 sublineage, 24.87% to the A1/A2 sublineages, and 3.13% to B1/B2 sublineages. In addition, the A4 sublineage T178G (P<0.001) and the A1/A2 sublineages T350G and A442C (P<0.001) were associated with persistent HPV16 infection. L1 and LCR variants were found to be common in this population. Nonetheless, no significant relation was identified between the L1 or LCR variants and the persistence of infection (P>0.05).

Conclusions: HPV16 E6 variants in the Shanghai Pudong District mainly belong to the A4 sublineage, and detection of the specific HPV E6 T178G genotype may be considered a risk factor for viral persistence and progression to other cervical diseases.