Prevalence of antibodies to human papillomavirus type 8 in human sera

The epidermodysplasia verruciformis-associated human papillomavirus type 8 (HPV-8) poses a high risk for malignant conversion of skin lesions in patients with epidermodysplasia verruciformis. For seroepidemiological studies, the HPV-8 open reading frames for E1, E2, E4, E6, E7, and L1 were bacterially expressed as beta-galactosidase fusion proteins, which were purified by preparative gel electrophoresis. Cleavage with the protease FXa at the engineered recognition site separated the beta-galactosidase polypeptide part from the viral polypeptide. Western blot analysis of 445 serum samples from a randomly selected population with the entire L1 as antigen revealed HPV-8-specific immunoglobulin G antibodies in 20% of the samples. The percentage of positive sera did not significantly differ in different age groups. In some sera, we could also detect immunoglobulin M antibodies. The use of two shortened L1 polypeptides as antigen indicated that there are at least two reactive epitopes in the case of HPV-8 L1. Several sera contained antibodies to the early proteins E1, E2, E4, and E7. E1 and E7 were predominantly detected by sera which were negative for L1. In one case, we found antibodies to E6. Two of four sera of patients with epidermodysplasia verruciformis reacted with HPV-8 L1. The prevalence of anti-HPV-8-L1 antibodies in patients with malignant melanomas was comparable to that in the normal population (27.8%) but was significantly higher in patients with cervical cancer (37.5%), basaliomas (40%), and squamous cell skin carcinomas (72.7%) and in immunocompromised patients with Hodgkin's disease (47.7%).