Oral human papillomavirus infection in men might contribute to HPV serology

The prospective Finnish Family HPV Study evaluated the dynamics of human papillomavirus (HPV) infection within families. Here, we focused on HPV serology in men. Seroprevalence at baseline, seroconversion and decay of low-risk (LR)-HPV6 and 11, and high risk (HR)-HPV16, 18 and 45 L1 antibodies in 122 men at 12, 24 and 36 months were determined using Luminex-based multiplex HPV serology, and correlated with demographic data. At baseline, seropositivity to HPV6, 11, 16, 18 and 45 was observed in 41.0, 11.5, 23.0, 13.9 and 5.7 % of the men, respectively. In univariate analysis, LR-HPV seropositivity was related to smoking status, history of genital warts and being seropositive to HR-HPV. Oral HR-HPV DNA and baseline LR-HPV seropositivity predicted HR-HPV seropositivity. Seroconversion to HPV6, 11, 16, 18 and 45 antigens during follow-up was found in 24.6, 11.5, 5.7, 5.7 and 0.8 %, respectively. Seroconversion to LR-HPV was negatively related to a higher number of children and oral sex, and positively associated with seroconversion to HR-HPV. In multivariate analysis, the same predictors remained significant except for the number of children. In univariate generalised estimating equations (GEE) for HR-HPV, being seroconverted to LR-HPV was the only predictor, but lost its significance in multivariate analyses. Decay of all HPV L1 antibodies was rare and observed in 0-2 %. The HPV antibody profile in men was dominated by response to HPV6, also showing the highest cumulative seroconversion. Oral HPV infection might affect HPV serology: (1) HPV DNA in oral mucosa is associated with baseline HR-HPV seropositivity and (2) practising oral sex significantly reduces longitudinal seroconversion to HPV6 and/or 11.