Kinetics of DNA load predict HPV 16 viral clearance.

ABSTRACT

INTRODUCTION: While high HPV 16 viral load measured at a single time point is associated with cervical disease outcomes, few studies have assessed changes in HPV 16 viral load on viral clearance. OBJECTIVE: To measure the association between changes in HPV 16 viral load and viral clearance in a cohort of Thai women infected with HPV 16. STUDY DESIGN: Fifty women (n=50) between the ages of 18-35 years enrolled in a prospective cohort study were followed up every three months for two years. Women positive for HPV 16 DNA by multiplex TaqMan assay at two or more study visits were selected for viral load quantitation using a type-specific TaqMan based real-time PCR assay. The strength of the association of change in viral load between two visits and viral clearance at the subsequent visit was assessed using a GEE model for binary outcomes. RESULTS: At study entry, HPV 16 viral load did not vary by infection outcome. A >2 log decline in viral load across two study visits was found to be strongly associated with viral clearance (AOR 5.5, 95% CI 1.4-21.3). HPV 16 viral load measured at a single time point was not associated with viral clearance. CONCLUSIONS: These results demonstrate that repeated measurement of HPV 16 viral load may be a useful predictor in determining the outcome of early endpoints of viral infection.