Association between multiple infection patterns of HPV33 and the risk of cervical carcinogenesis

Human papillomavirus 33 (HPV33) is among the five most prevalent HPV genotypes in China and is commonly involved in co-infections. However, the synergistic effects of specific genotype combinations on cervical carcinogenesis remain incompletely understood. This study aimed to characterize HPV33 co-infection patterns and their associated genetic variations in relation to cervical lesion progression.

We enrolled 1,770 HPV33-positive patients from the Obstetrics and Gynecology Hospital of Fudan University between 2018 and 2023, including 852 with HPV33 single infections and 918 with multiple infections. Logistic regression was used to assess associations between co-infection characteristics and cervical histopathological results. In a subset of 90 cases, the full-length L1 gene of HPV33 was sequenced and phylogenetically analyzed to evaluate genomic variation by infection status.

The number of HPV33 co-infecting genotypes was positively correlated with cervical lesion severity (p < 0.05). HPV52, HPV16, and HPV58 were the most frequent co-infecting genotypes and were associated with an increased risk of cervical intraepithelial lesion progression: HPV16 (OR 1.97, 95% CI: 1.17-3.34), HPV52 (OR 2.07, 95% CI: 1.26-3.39), HPV58 (OR 2.83, 95% CI: 1.42-5.64). However, among HPV33 multiple infections (≥3 genotypes), only those that involved HPV16 were directly and significantly associated with an increased risk of cervical lesions, with ORs increasing from 1.72 (95% CI: 1.03-2.85) for LSIL to 3.16 (95% CI: 1.75-5.72) for HSIL or worse. Phylogenetic analysis classified most HPV33 sequences into sublineage A1, with no significant difference in L1 gene mutations between single and multiple infections.

HPV33 co-infection patterns, particularly those involving HPV16, are consistently associated with an elevated risk of high-grade cervical lesions in this Chinese cohort. These findings underscore the differential risks associated with distinct HPV33 co-infection patterns and support genotype-specific risk stratification in cervical cancer screening programs.