Comparison of HPV neutralizing and IgG antibodies in unvaccinated female adolescents

Aims: To analyze the consistency between HPV neutralizing antibodies and specific total IgG antibodies in unvaccinated females. Materials & methods: Serum samples from 978 unvaccinated Chinese females aged 9-26 years were measured for antibodies against HPV-16 and HPV-18 using simultaneous pseudovirus-based neutralization assay and ELISA. Results: There was a moderate level of consistency between HPV neutralizing antibodies and specific IgG in females aged 18-26 years (Cohen's kappa coefficient for HPV-16 and HPV-18: 0.52 and 0.38) and poor consistency in those aged 9-17 years (Cohen's kappa coefficient <0.05). However, Cohen's kappa coefficient remained almost unchanged in sensitivity analysis when the IgG antibody cut-off value was raised. Conclusion: HPV neutralizing antibodies are a more specific indicator for the evaluation of HPV natural humoral immunity.