Natural history of human papillomavirus type 16 virus-like particle antibodies in young women.

Immunization with a vaccine of human papillomavirus (HPV) type 16 virus-like particles (VLPs) can reduce incidence of HPV-16 infection and its related cervical intraepithelial neoplasia. However, development of detectable antibodies to VLPs does not always occur after natural HPV infection. This study examined prospectively for seroconversion and duration of antibodies to HPV-16 VLPs and their associated host and viral factors. Six-hundred eight subjects were tested for HPV DNA biannually and for IgG and IgA antibodies to HPV-16 VLPs annually for 3 years. Both IgG and IgA antibodies to HPV-16 VLPs were predominantly type specific. Women with cervicovaginal HPV-16 infection were 8-10 times more likely to seroconvert than those with infection of HPV-16-related types. Among subjects who had an incident infection with HPV-16, a maximum of 56.7% became seropositive for IgG within 8.3 months and 37.0% had IgA within 14 months. Detectable seroconversion was a slow process that required sufficient antigenic exposure associated with either a high viral load (relative risk = 5.7 for IgG) or persistent infection of HPV-16 (relative risk = 3.4 for IgA). The median duration for both types of antibodies was approximately 36 months. Antibodies could persist for a long period of time if the initial antibody levels were high or if there was continued antigenic exposure.

Polymer-based enzyme-linked immunosorbent assay using human papillomavirus type 16 (HPV16) virus-like particles detects HPV16 clade-specific serologic responses.

Human papillomavirus type 16 (HPV16) virus-like particles (VLP) were used as antigen in a polymer enzyme-linked immunosorbent assay (ELISA) to measure antibodies to HPV capsid proteins. Serum samples from 575 college women, previously tested for the presence of cervicovaginal HPV DNA, were analyzed. The prevalences of anti-HPV16 VLP antibodies at baseline were 14.1% for immunoglobulin G (IgG) and 6.4% for IgA. The seroprevalences of IgG in women with cervicovaginal HPV16, HPV16-related types, and other HPV types were 55, 33, and 19%, respectively (P < 0.001), compared to the prevalence in women without an HPV infection (10%). HPV VLP IgA seropositivity was associated with high HPV16 VLP IgG optical density values. The seropositivity of IgG antibodies was independently associated with infection with HPV16 or HPV16-related types, increased number of lifetime male partners for vaginal sex, having sex with men >/= 5 years older, history of abnormal PAP smear, older age, and living separately from parents. Use of HPV16 VLP polymer ELISA detects clade-specific responses and suggests an HPV16 VLP vaccine may have broader protection that initially anticipated.

Risk factors for subsequent cervicovaginal human papillomavirus (HPV) infection and the protective role of antibodies to HPV-16 virus-like particles.

A high incidence of initial infection with human papillomavirus (HPV) was previously reported in a cohort of 608 women monitored at 6-month intervals for 3 years. Risk factors for subsequent infections with different HPV types and whether antibodies against HPV-16 virus-like particles (VLPs) protected against these infections were examined. Subsequent infections with HPV are very common. Seventy percent of women acquired a different HPV type within 24 months of the initial infection. Risk factors included being nonwhite, having an increased number of male sex partners, and having had a new male sex partner. Use of oral contraceptive pills was protective. A sustained high level of IgG antibody to HPV-16 VLPs was associated with reduced risk for subsequent infection with HPV-16 and its genetically related types (i.e., HPV-31, -33, -35, -52, and -58).