Characterization of IgA response among women with incident HPV 16 infection

AbstractPrevious studies have characterized the prevalence and duration of serum IgG antibodies to human papillomavirus type 16 (HPV 16) in a well-studied cohort of college women, using viruslike particle- (VLP) based ELISAs. In this study IgA antibodies in cervical secretions and sera were examined using a newly developed capsomer-based ELISA and the patterns observed for serum IgG, serum IgA, and cervical IgA antibodies were compared. The median time to antibody detection from the first detection of HPV 16 DNA was 10.5 months for IgA in cervical secretions and 19.1 months for serum IgA. Serum IgA antibody conversion was observed less frequently and occurred later than IgA conversion in cervical secretions (P = 0.011) or serum IgG conversion (P = 0.051). The median time to antibody reversion, following seroconversion, was 12.0 months for IgA in cervical secretions and 13.6 months for serum IgA, whereas approximately 20% of women with serum IgG antibodies reverted within 36 months. Thus, the duration of IgA in cervical secretions and sera was shorter than the duration of serum IgG (P = 0.007 and 0.001)

Incidence of genital warts among the Hong Kong general adult population

<p>Abstract</p> <p>Background</p> <p>The objective of this study is to estimate the incidence of genital warts in Hong Kong and explore a way to establish a surveillance system for genital warts among the Hong Kong general population.</p> <p>Methods</p> <p>A total of 170 private doctors and all doctors working in the 5 local Social Hygiene Clinics (SHC) participated in this study. During the 14-day data collection period (January 5 through18, 2009), the participating doctors filled out a log-form on a daily basis to record the number of patients with genital warts. The total number of new cases of genital warts presented to private and public doctors in Hong Kong was projected using the stratification sampling method.</p> <p>Results</p> <p>A total of 721 (0.94%) adults presented with genital warts to the participating doctors during the two-week study period, amongst them 73 (10.1%) were new cases. The projected number of new cases of genital warts among Hong Kong adults was 442 (297 male and 144 female) during the study period. The incidence of genital warts in Hong Kong was estimated to be 203.7 per 100,000 person-years (respectively 292.2 and 124.9 per 100,000 person-years for males and females).</p> <p>Conclusions</p> <p>The incidence of genital warts is high among adults in Hong Kong. The study demonstrates the importance of collecting surveillance data from both private and public sectors.</p

Humoral Immune Response Recognizes a Complex Set of Epitopes on Human Papillomavirus Type 6 L1 Capsomers

Although epitope mapping has identified residues on the human papillomavirus (HPV) major capsid protein (L1) that are important for binding mouse monoclonal antibodies, epitopes recognized by human antibodies are not known. To map epitopes on HPV type 6 (HPV6) L1, surface-exposed loops were mutated to the corresponding sequence of HPV11 L1. HPV6 L1 capsomers had one to six regions mutated, including the BC, DE, EF, FG, and HI loops and the 139 C-terminal residues. After verifying proper conformation, hybrid capsomers were used in enzyme-linked immunosorbent assays with 36 HPV6-seropositive sera from women enrolled in a study of incident HPV infection. Twelve sera were HPV6 specific, while the remainder reacted with both HPV6 and HPV11 L1. By preadsorption studies, 6/11 of these sera were shown to be cross-reactive. Among the HPV6-specific sera there was no immunodominant epitope recognized by all sera. Six of the 12 sera recognized epitopes that contained residues from combinations of the BC, DE, and FG loops, one serum recognized an epitope that consisted partially of the C-terminal arm, and three sera recognized complex epitopes to which reactivity was eliminated by switching all five loops. Reactivity in two sera was not eliminated even with all six regions swapped. The patterns of epitope recognition did not change over time in women whose sera were examined 9 years after their first-seropositive visit