Human papillomavirus (HPV) 18 genetic variants and cervical cancer risk in Taizhou area, China

Abstract

Human papillomavirus (HPV) type 18 is predominantly associated with the development of cervical adenocarcinomas, whereas data on HPV18 genetic variability in China are limited. HPV18 genetic variants were formed phylogenetic tree, including lineages A, B, and C. We aimed to evaluate the diversity of HPV18 genetic variants by sequencing the entire E6, E7 and L1 genes. Between 2012 and 2015, a total of 138 (0.8%, 138/17669) women with single HPV18 infection were selected in this study. Finally, we observed 122 HPV18 isolates of the complete E6-E7-L1 sequences, and obtained 36 distinct variation patterns which the accession GenBank numbers as KY457805-KY457840. Except KY457805, KY457813, KY457819, KY457827, KY457829, the rest of HPV18 isolates (81.1%, 31/36) are novel variants. All of HPV18 variants belong to lineage A, while no lineage B, and C was found in our population of Taizhou region, Southeast China. Sublineage A1 was the most common variants (85.2%, 104/122), followed by sublineage A4, A3 and A5, while no sublineage A2 was obtained. Based on the tree topologies, there were three newly identified candidates' sublineages A6-A8. Out of 122 women, 67 (54.9%) had diagnosed by biopsy, including 49 women who diagnosed with cervicitis, 12 with cervical intraepithelial neoplasia (CIN)1, 4 with CIN2/3, and 2 with adenocarcinomas, respectively. Nevertheless, there was no association between HPV18 (sub) lineages and CIN1 or worse (CIN1+) lesions comparing with normal biopsies (P = .469). In conclusion, knowledge of the distribution of geographic/ethnical HPV18 genetic diversity provides critical information for developing diagnostic probes, epidemiologic correlate of cervical cancer risk and design of HPV vaccines for targeted populations.