In our previous study of the etiologic role of oncogenic human papillomavirus (HPV) types other than HPV16 and 18, we observed a significantly higher risk of cervical intraepithelial neoplasia Grades 2-3 (CIN2/3) associated with certain lineages of HPV types 31/33/45/56/58 [called high-risk (HR) variants] compared with non-HR variants. This study was to examine whether these intra-type variants differ in persistence of the infection and persistence-associated risk of CIN2/3. Study subjects were women who had any of HPV types 31/33/45/56/58 newly detected during a 2-year follow-up with 6-month intervals. For each type, the first positive sample was used for variant characterization. The association of reverting-to-negativity with group of the variants and CIN2/3 with length of positivity was assessed using discrete Cox regression and logistic regression, respectively. Of the 598 newly detected, type-specific HPV infections, 312 became undetectable during follow-up. Infections with HR, compared with non-HR, variants were marginally more likely to become negative [adjusted hazard ratio = 1.3; 95% confidence interval (CI), 0.9-1.8]. The adjusted odds ratio associating with the development of CIN2/3 was 3.0 (95% CI, 1.2-7.4) for persistent infections with HR variants for 6 months and 10.0 (95% CI, 3.8-38.0) for persistent infections with HR variants for 12-18 months as compared with the first positive detection of HR variants. Among women with non-HR variants, there were no appreciable differences in risk of CIN2/3 by length of positivity. Findings suggest that the lineage-associated risk of CIN2/3 was not mediated through a prolonged persistent infection, but oncogenic heterogeneity of the variants.
Keywords: cervical intraepithelial neoplasia; human papillomavirus; persistence; variants.
© 2016 UICC.