Occurrence of antibodies TO L1, L2, E4 and E7 gene products of human papillomavirus types 6b, 16 and 18 among cervical cancer patients and controls

Sera from 118 women of 33 to over 90 years of age, with or without a history of cervical squamous-cell carcinoma, were examined for the presence of antibodies to HPV-6b, HPV-16 and HPV-18, L1, L2, E4, and E7 gene products by the use of bacterially derived beta-Gal fusion proteins and Western-blot analysis. Among the cervical cancer patients, 29/46 (63.0%) were positive for antibodies to E4 and/or E7 of HPV-16 and/or E7 of HPV-18. In contrast, only 2 of 31 (6.5%) non-genital cancer patients and 4 of 41 (9.8%) healthy individuals were antibody-positive for HPV-16 E4 or E7, while antibodies to the homologous proteins of HPV-18 could not be detected. Prevalence rates of antibodies to the HPV-16/18 late proteins were 25/46 (54.3%) in the cervical carcinoma group, 13/31 (41.9%) among women with non-genital cancer types, and 18/41 (43.9%) among normal, healthy individuals. Antibodies to HPV-6b late gene products ranged between 6.5% and 12.2% in the different patient groups. Antibodies to HPV-6b E4 and E7 were detected only once. By studying an additional control group of 207 women with a different age distribution, age-dependence of antibodies to HPV gene products could be ruled out. Whereas antibodies to late proteins may indicate that, regardless of clinical stage, HPV infections are wide-spread among the female population, the striking difference between the prevalence rates of antibodies to early proteins of HPV-16 and HPV-18 among cervical cancer patients and controls (p less than 0.001) supports the idea of the involvement of these virus types in carcinogenesis of the cervix.