Human papillomavirus-related serological markers of invasive cervical carcinoma in Brazil.

Masked sera from 194 cases and 217 controls participating in a case-control 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 vitro transcription and translation in rabbit reticulocyte lysate were used 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% for either E6 or E7; and 21.1% versus 0.5% for both E6 and E7. The corresponding odds ratios were 35 ([95% confidence interval (CI)], 15-83), 10 (95% CI, 4-25), 28 (95% CI, 13-61) and 87 (95% CI, 10-736). The most marked contrast between cases and controls was observed for sera with high antibody titers (cpm > 6000) with an odds ratio of 239 (95% CI, 29-1946) for E6 or E7. Seroreactivity in cases was partially type specific; women who had HPV-16 DNA in the genital tract had higher antibody prevalence rates than those who were negative for HPV DNA. Reactivity to the E6 protein was associated with the stage of disease; the antibody prevalence was 62.7% in cases with stages II-IV and 31.0% in cases with stage I (P < 0.005). HPV-16 serology and HPV polymerase chain reaction were compared as markers for invasive cervical cancer.(ABSTRACT TRUNCATED AT 250 WORDS)