Kinetics of DNA load predict HPV 16 viral clearance

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.