Characterization of antibody response in women with naturally acquired HPV 16 infection using pseudovirion‐based neutralization assay

Abstract

Antibody response to HPV16 infection has mainly been studied using Virus‐like Particle (VLP)‐based ELISA assays of serum. Local antibody response at the cervix may be a better indicator of protection. In this study, the pseudovirion–based neutralization assay was adapted to measure antibody titers in response to naturally acquired HPV 16 infection in both serum and cervical mucous samples. Samples were collected from women (n=230) attending colposcopy clinics and matched for age, race and HPV16 DNA status. Results showed that 54.1% of sera and 17.2% of mucous samples had positive antibody titers. Correlation of titers between the matched sera and mucosal samples was poor (ρ= 0.54), with sera being more likely to be positive for an antibody response (κ= 0.25). Univariate analysis of the data showed HPV 16 DNA status was significantly associated with both serum and mucosal antibody titer, but not with HPV 16 viral load or cervical disease. Comparison of the neutralization assay to the standard HPV 16 VLP‐based IgG ELISA also showed a fair correlation (ρ= 0.74) between titers and absorbance. In naturally acquired infections, serum antibodies are a more sensitive measure of exposure than mucosal antibodies. This study was supported in part by the National Cancer Institute's Early Detection Research Network Interagency Agreement Y1‐CN‐0101‐01.