Humoral immune response against proteins E6 and E7 in cervical carcinoma patients positive for human papilloma virus type 16 during treatment and follow-up

To investigate the humoral immune response to transforming proteins E6 and E7 of human papillomavirus type 16 before and after treatment and during follow-up, consecutive serum samples from 36 cervical cancer patients whose tumours were found to contain human papillomavirus type 16 DNA by use of the polymerase chain reaction were tested using in vitro translated proteins E6 and E7 in a radioimmunoprecipitation assay and in an E7 synthetic peptide enzyme immunoassay. Antibody levels against E6 and E7 as measured by radioimmunoprecipitation assay showed a nearly identical pattern. Seronegative patients remained seronegative throughout treatment and follow-up. Seropositive patients showed either a decrease in antibody level or stable antibody levels during treatment. In contrast to patients without evidence of disease at the end of the study, the majority of patients with recurrent disease showed increasing antibody levels during the follow-up period. These results indicate that, in patients who are seropositive before treatment antibody levels against E6 and E7 of human papillomavirus type 16 after treatment are closely linked to treatment response. The use of the more sensitive radioimmunoprecipitation assay did not lead to a better correlation of antibody levels with clinical disease status of the patients than the use of the enzyme immunoassay.