Changes in DNA Level of Oncogenic Human Papillomaviruses Other Than Types 16 and 18 in Relation to Risk of Cervical...

Epidemiologic data addressing clinical relevance of viral load fluctuation of oncogenic types other than human papillomavirus (HPV) types 16 and 18 are limited.

A type-stratified set of infections by non-HPV16/18 oncogenic types that were detected at ≥2 visits was randomly selected from women who were enrolled in a clinical trial and followed every 6 months for 2 years for detection of HPV and cervical intraepithelial neoplasia grades 2 and 3 (CIN2/3). Type-specific viral load was measured on both first and last HPV-positive cervical swab samples.

CIN2/3 was initially confirmed at the last HPV-positive visit for 67 of 439 infections. The increase in risk of CIN2/3 was associated with high, relative to low, viral load at both first and last positive visits [OR_adjusted = 3.67; 95% confidence interval (CI), 1.19-11.32] and marginally associated with a change of viral load from low to high levels (OR_adjusted = 3.15; 95% CI, 0.96-10.35) for infection by species group alpha-9 non-HPV16 oncogenic types but not species group alpha-5-7 non-HPV18 oncogenic types. Among women with an initial diagnosis of CIN2/3 at the first positive visit, CIN2/3 was more frequently redetected at the last positive visit for infections with, compared with without, high DNA load of species group alpha-9 non-HPV16 oncogenic types at both visits (P _exact = 0.04).

In agreement with data on baseline viral load, the viral load change-associated risk of CIN2/3 differs by HPV species groups.

These findings underscore the importance of distinguishing species groups in future studies of clinical relevance of HPV DNA load.