Variants of human papillomavirus type 16 predispose toward persistent infection

A cohort study of 292 Chinese women was conducted to determine the relationship between human papillomavirus (HPV) type 16 variants and persistent viral infection. Enrolled patients were HPV16 positive and had both normal cytology and histology. Flow-through hybridization and gene chip technology was used to identify the HPV type. A PCR sequencing assay was performed to find HPV16 E2, E6 and E7 gene variants. The associations between these variants and HPV16 persistent infection was analyzed by Fisher's exact test. It was found that the variants T178G, T350G and A442C in the E6 gene, as well as C3158A and G3248A variants in the E2 gene were associated with persistent HPV16 infection. No link was observed between E7 variants and persistent viral infection. Our findings suggest that detection of specific HPV variants would help identify patients who are at high risk for viral persistence and development of cervical neoplasia.