Development of a proficiency testing program for HPV serology assays used to evaluate antibody responses in vaccine trials.

In this study, a proficiency panel was created for evaluation of assay performance and inter- and intra-laboratory assay comparisons, especially the ability to accurately measure negative, low, intermediate, and high levels of HPV type-specific antibodies. Comprised of 80 deidentified samples, this panel is designed for individual labs to evaluate assay performance characteristics on a biennial basis, to promote standardization of methodology and harmonization of data from human papillomavirus (HPV) serology tests in vaccine trials. The proficiency panel was qualified using 2 types of assays (singleplex Enzyme-Linked Immunosorbent Assays [ELISAs] or Multiplex antibody-binding assays and Pseudovirion-based neutralization assays [PBNAs]) in 10 laboratories from 7 countries, monitoring HPV antibody responses for up to 9 HPV types and using 3 different analysis methods. Sensitivity, specificity, and correlations (concordance, accuracy, and precision) were evaluated for each HPV type. In laboratories that tested all 80 samples, results from most (74/80) samples were reported with 100% accuracy across all 9 HPV types. The average sensitivity and specificity for singleplex and multiplex antibody binding assays ranged from 86.7% to 98.3% (sensitivity) and 84.2% to 94.3% (specificity), while the average sensitivity and specificity for the Pseudovirion (PsV)-based neutralization assays (PBNA) ranged from 87.6% to 99.4% (sensitivity) and 52.4% to 94.4% (specificity). This proficiency panel will help with assessing performance characteristics of HPV serology assays used in clinical trial studies and assure the data generated from these assays is harmonized.