Serum Immunoglobulin A Response to Human Papillomavirus Type 16 Virus-Like Particles in Human Immunodeficiency Virus (HFV)-Positive and High-Risk HIV-Negative Women

Serum samples from 2008 human immunodeficiency virus (HIV)-positive and 551 HIV-negative women were tested for immunoglobulin A (IgA) to human papillomavirus (HPV) type 16 capsids. IgA seropositivity was lower than previously reported IgG seropositivity (7% vs. 51%), but, like IgG antibodies, HPV 16 IgA was associated with sexual behavior, cervicovaginal HPV 16 DNA, and cytological abnormalities. IgA seropositivity was higher in HIV-positive women than in HIV-negative women (7.7% vs. 4.9%; P = .02), but the association was lost after adjustment for HPV 16 cervicovaginal infection. IgA, but not IgG, seropositivity was associated with progression to high-grade cytological abnormalities (relative hazard [RH], 2.2 [95% confidence interval, 1.2-4.2]), raising the possibility that an IgA response to HPV 16, as described for other DNA viruses, may be a marker of persistent viral replication. The risk of incident infection with non-16-related HPV types was increased in IgA seropositive women (RH, 1.8 [95% confidence interval, 1.3-2.6]), compared with seronegative women (RH, 2.2 [95% confidence interval, 0.9-5.4]), but there was no difference in the risk of incident HPV 16 or HPV 16-related infections. This may be evidence of partial type-specific or clade-specific immunity conferred by seropositivity to HPV 16 capsids.