HUMAN PAPILLOMAVIRUS-RELATED SEROLOGICAL MARKERS OF INVASIVE CERVICAL-CARCINOMA IN BRAZIL

Masked sera from 194 cases and 217 controls participating in a case-co ntrol study of cervical cancer in Brazil were examined for antibodies to human papillomavirus (HPV) 16 E6 and E7 by radioimmunoprecipitation assay. Radiolabeled full-length E6 and E7 proteins expressed by in vi tro transcription and translation in rabbit reticulocyte lysate were u sed as antigens. The antibody prevalences in cases and controls were: 54.1% versus 6% for E6; 30.4% versus 4.6% for E7; 63.4% versus 10.1% f or either E6 or E7; and 21.1% versus 0.5% for both E6 and E7. The corr esponding odds ratios were 35 ([95% confidence interval (CI)], 15-83), 10 (95% Cl, 4-25), 28 (95% CI, 13-61) and 87 (95% Cl, 10-736). The mo st marked contrast between cases and controls was observed for sera wi th high antibody titers (cpm > 6000) with an odds ratio of 239 (95% Cl , 29-1946) for E6 or E7. Seroreactivity in cases was partially type sp ecific; women who had HPV-16 DNA in the genital tract had higher antib ody prevalence rates than those who were negative for HPV DNA. Reactiv ity to the E6 protein was associated with the stage of disease; the an tibody prevalence was 62.7% in cases with stages II-IV and 31.0% in ca ses with stage I (P < 0.005). HPV-16 serology and HPV polymerase chain reaction were compared as markers for invasive cervical cancer. The s ensitivity and specificity estimates were: 63.4% and 89.9% for HPV-16 serology; 53.8%