Safaeian M, et al. - In order to assess the role of antibodies produced after infection with human papillomavirus 18 (HPV-18) and subsequent protection from HPV-18 infection, researchers pooled data from the control arms of the Costa Rica Vaccine Trial and the PATRICIA trial. In this work, high HPV-18 naturally acquired antibodies were noted to be correlated with partial protection from future HPV-18 infections and associated lesions.

Methods

• Data was obtained from the control arms of the Costa Rica Vaccine Trial and the PATRICIA trial.
• Researchers performed a comparison of the risk of newly detected 1-time HPV-18 infection, HPV-18 1-year persistent infection (12MPI), and HPV-18–associated atypical squamous cells of undetermined significance or greater (ASC-US+) lesions between HPV-18 seropositive and seronegative women using Poisson regression.

Results

• Researchers noted high HPV-18 antibodies at enrollment to be associated with reduced subsequent HPV-18 detection (P trend = 0.001; relative rate [RR] = 0.69; 95% confidence interval [CI], 0.47–1.01 for the third quartile; RR = 0.63; 95% CI, 0.43–0.94 for the fourth quartile, compared to seronegative).
• A decreasing trend in the risk of 12MPI was noted with increasing antibodies (P trend = 0.06; RR = 0.72; 95% CI, 0.29–1.77; RR = 0.42; 95% CI, 0.13–1.32 for the third and fourth quartiles, respectively).
• Lastly, a significant decreased risk of HPV-18 ASC-US+ was identified with increasing antibody (P trend = 0.01; RR = 0.46; 95% CI, 0.21–0.97 for the fourth quartile).
• A significant decreased risk of HPV-16 infection, 12MPI, and ASC-US+ was observed with increasing HPV-16 antibody level.