Anogenital Human Papillomavirus (HPV) Infection, Seroprevalence, and Risk Factors for HPV Seropositivity Among Sexually Active Men Enrolled in a Global HPV Vaccine Trial.

BACKGROUND: In men, the incidence of human papillomavirus (HPV)-related cancer is rising, but data regarding male HPV infection and seroprevalence are available from only a few countries. METHODS: This analysis of a global HPV vaccine trial evaluated baseline data from 1399 human immunodeficiency virus-negative heterosexual men (HM) and men who have sex with men (MSM). Key objectives included assessment of HPV prevalence and risk factors for seropositivity to 9-valent HPV (9vHPV) vaccine types (6, 11, 16, 18, 31, 33, 45, 52, and 58), and concordance between seropositivity and prevalent HPV type. RESULTS: Overall, 455 of 3463 HM (13.1%) and 228 of 602 MSM (37.9%) were HPV DNA positive for any 9vHPV vaccine type at baseline. Infection prevalence and seroprevalence (≥1 9vHPV vaccine type) were 13.2% and 8.1%, respectively, among 333 HM from Europe, and 37.9% and 29.9%, respectively, among 335 MSM from Europe or North America. Among men with baseline infection, MSM had higher seroprevalence for concordant HPV types (39.5% vs 10.8% in HM). The seropositivity risk (irrespective of baseline infection status) was higher among MSM versus HM (age-adjusted odds ratio, 3.0 [95% confidence interval, 2.4-6.4]). Among MSM, statistically significant seropositivity risk factors included younger age at sexual debut, higher number of receptive anal sex partners, and less frequent condom use. No factors assessed were associated with seropositivity in HM. CONCLUSIONS: Higher proportions of MSM than HM were HPV DNA positive and seropositive, and concordance between HPV DNA positivity and seropositivity, a potential marker of true infection versus carriage, was higher in MSM. Most MSM and HM were seronegative for all 9vHPV vaccine types, suggesting the potential benefit of catch-up vaccination after sexual debut.Clinical Trials Registration. NCT00090285.

Comparison of a VLP-based and GST-L1-based multiplex immunoassay to detect vaccine-induced HPV-specific antibodies in first-void urine.

Vaccine-induced human papillomavirus (HPV) antibodies originating from cervicovaginal secretions were recently shown to be detectable in first-void (FV) urine. This presents a novel opportunity for noninvasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials. With a view towards method optimization, this study compared the measurement of HPV antibodies in FV urine using a multiplex L1/L2 virus-like particles (VLP)-based ELISA (M4ELISA) with previously reported results using a glutathione S-transferase (GST)-L1-based immunoassay (GST-L1-MIA). We tested 53 paired FV urine and serum samples from 19- to 26-year-old healthy women, unvaccinated (n = 17) or vaccinated with either the bivalent or quadrivalent HPV-vaccine during adolescence (n = 36). HPV6/11/16/18 antibodies were measured using M4ELISA and compared with GST-L1-MIA results. Inter-assay and inter-specimen correlations were examined using the Spearman's rank test (rs). As expected, lower HPV antibody concentrations were found in FV urine than in serum. Vaccinated women had significantly higher HPV6/11/16/18 antibody levels in both FV urine and serum compared with those unvaccinated (M4ELISA; FV urine P = .0003; serum P ≤ .0001). HPV antibody levels in FV urine and serum showed a significant positive correlation (M4ELISA anti-HPV6/11/16/18, rs = 0.85/0.86/0.91/0.79, P ≤ .001). Despite assay differences, there was moderate to good correlation between M4ELISA and GST-L1-MIA (FV urine anti-HPV6/11/16/18, rs = 0.86/0.83/0.89/0.53, P ≤ .0001; serum anti-HPV6/11/16/18, rs = 0.93/0.89/0.94/0.75, P ≤ .0001). FV urine HPV antibody detection is comparable with both assays, further supporting this noninvasive sampling method as a possible option for HPV vaccine assessment. Approaches to improve the sensitivity and larger studies are warranted to determine the feasibility of FV urine for vaccine-induced HPV antibody detection.

Human papillomavirus seroprevalence and seroconversion following baseline detection of nine human papillomavirus types in young women.

BACKGROUND: Estimates of the humoral immune response to incident human papillomavirus (HPV) infections are limited. METHODS: In this post hoc analysis of 3875 women aged 16-23 years from a 4-valent HPV vaccine trial (NCT00092482), HPV seroprevalence on day 1 was measured with a 9-valent HPV (HPV 6/11/16/18/31/33/45/52/58) competitive Luminex immunoassay and compared with cervical/external genital HPV detection by polymerase chain reaction. In the control group, among women who were HPV DNA‒negative on day 1, seroconversion following initial HPV detection was estimated using Kaplan-Meier methods. RESULTS: Type-specific HPV seropositivity among women with no day 1 cervical/external genital HPV detection was 0.6%-3.6%. Women with any 9-valent HPV (9vHPV) cervical/external genital detection (796/3875; 20.5%) had concordant seropositivity ranging from 13.4% (HPV 45) to 38.5% (HPV 6). Among women in the control group who were negative for all HPV types on day 1, seroconversion by month 30 after initial detection ranged from 29% (HPV 45) to 75% (HPV 16). CONCLUSIONS: Humoral immune response to HPV is variable and dynamic, depending on type-specific exposure. This longitudinal analysis provides insight into the relationship between incident infection and seropositivity. CLINICALTRIALS: gov; NCT00092482 https://clinicaltrials.gov/ct2/show/NCT00092482.

Non-invasive Assessment of Vaccine-Induced HPV Antibodies via First-Void Urine.

The potential of first-void (FV) urine as a non-invasive method to monitor human papillomavirus (HPV) vaccination has been reported, mainly focusing on urine as a sample to assess HPV DNA. Besides HPV DNA, vaccine-induced HPV antibodies originating from cervicovaginal secretions were recently shown to be detectable in FV urine as well. This presents a novel opportunity for non-invasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials. The simultaneous assessment of both HPV infection and immunogenicity on a non-invasive, readily obtained sample is particularly attractive.

Comparison of antibody responses to human papillomavirus vaccination as measured by three assays.

BACKGROUND: Different assays, including the competitive Luminex immunoassay (cLIA), secreted alkaline phosphatase neutralization assay (SEAP-NA), and virus-like particle-based ELISA, are commonly used to measure antibody responses after human papillomavirus (HPV) vaccination. Direct assay comparisons aid interpretation of immunogenicity data evaluated by different assays. METHODS: We compared cLIA to SEAP-NA and ELISA among 51 HPV16/18-vaccinated women enrolled in the Costa Rica Vaccine Trial. We tested replicate serum samples collected at months 0, 1, and 12 by HPV16/18 cLIA, SEAP-NA, and ELISA. For a subset (N = 10), we further tested month 6, 24 and 36 samples. We calculated seroprevalence estimates and Spearman rank correlation coefficients comparing cLIA to SEAP-NA and ELISA. RESULTS: After one vaccine dose, seroprevalence by SEAP-NA and ELISA was 100% (both HPV16 and HPV18), and by cLIA was 96% (95% CI 87-100%) for HPV16 and 71% (95% CI 56-83%) for HPV18. Seroprevalence was 100% by all assays after three doses. Correlation between assays was high after one vaccine dose [cLIA/SEAP-NA ρ = 0.91 (HPV16) and ρ = 0.86 (HPV18); cLIA/ELISA ρ = 0.84 (HPV16) and ρ = 0.74 (HPV18); all p < 0.001] and remained high through month 36. Ratios of mean antibody levels to seropositivity cutoffs at month 36 were lower for cLIA than for SEAP-NA or ELISA, particularly for HPV18 (HPV18 ratio for cLIA 1.9, SEAP-NA 3.5, ELISA 3.4). CONCLUSION: Though correlation between cLIA and SEAP-NA/ELISA is high and stable after vaccination, the assays differ in scale and sensitivity, with notable differences after one vaccine dose and for HPV18. Our results demonstrate that comparisons of antibody responses to HPV vaccination measured by different assays are approximate, and must consider biological and technical differences between assays.