ABSTRACT
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). CONCLUSION: 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.
ABSTRACT
The study aimed to detect the variants of human papillomavirus (HPV) type 16 E6 and E7 in patients with cervical high-grade squamous intraepithelial lesion (HSIL), and to determine the existence and recurrence of persistent infection after treatment with loop electrosurgical excision procedure (LEEP). Preoperatively collected cervical exfoliated cells from 100 HPV 16 positive HSIL patients enrolled in the study were used to test for E6 and E7 variants. Follow-ups which included TCT, HPV test, and colposcopy were performed every 3 months after the operation, and colposcopic biopsy and endocervical curettage were performed for patients with abnormalities. Patients were followed for 2 years, and recurrence was defined as detecting low-grade squamous intraepithelial lesion (LSIL) or relapse of HSIL in 1 year. In 81% of patients, the E6 variant was the Asian prototype (As.P), 14% of patients had the European variant, 2% had the European prototype (EP), and 3% had the African 1 variant (Af1). The HPV16 could be easily cleared by LEEP in patients with As.P. Persistent infection or recurrence was very rare in this group. The patients with European variants T350G or A442C had a significantly higher incidence of persistent and recurring HPV16 infection. In conclusion, (i) in most cases, As.P caused HSIL. (ii) The European variant E6 T350G/A442C may be associated with higher rates of recurring and persistent HPV16 infection after the LEEP. (iii) The E7 gene mutation may not be a risk factor for recurring HSIL caused by HPV16 or persistent infection. J. Med. Virol. 88:1982-1988, 2016. © 2016 Wiley Periodicals, Inc.
