Abstract
To investigate the clinical significance of the enhanced sensitivity of antibody detection by radio immunoprecipitation assays (RIPA), using in vitro translated HPV-16 E6 and E7 proteins, over synthetic-peptide enzyme-linked immunosorbent assay (ELISA), RIPA for HPV-16 E6 and E7 were performed. The results obtained with E6 and E7 RIPA were related to clinico-pathological data from cervical carcinoma patients positive for HPV type 16 DNA in their primary tumour. The data obtained with E6 and E7 RIPA were then compared to the results obtained using the E7/6-35 synthetic-peptide ELISA. The prevalence of antibodies to E6, E7, E6 and/or E7 and E6 and E7, as determined by RIPA, was significantly higher in cervical cancer patients than in both controls and cervical intraepithelial neoplasia patients. Odds ratios, calculated for cervical carcinoma patients versus controls, ranged from 7.4 to 15.4. Antibodies to E6 and/or E7 were largely restricted to patients with HPV DNA in their primary tumour. Analysis of the relation between prevalence of antibodies to E6 and E7 and clinico-pathological parameters was limited to 85 patients positive for HPV-16 DNA. The strongest relation with clinico-pathological data, such as lesion size, lymph node involvement, and prognosis, was found for E7 synthetic-peptide ELISA, whereas E6 and E7 RIPA did not reach significance. The significance of these findings is discussed.