THE E7 PROTEIN OF HUMAN PAPILLOMAVIRUS (HPV) TYPE-16 EXPRESSED BY RECOMBINANT VACCINIA VIRUS CAN BE USED FOR DETECTION OF ANTIBODIES IN SERA FROM CERVICAL-CANCER PATIENTS

Sera from 128 Mexican cervical cancer patients (age 30-80; mean 53.6) and from 47 healthy women (age 25-69; mean 49.2) were investigated usi ng a newly developed assay for the detection of serum antibodies to th e human papillomavirus (HPV) type 16 early protein E7, This test (CIPA ), based upon immunoprecipitation followed by Western blot analysis, u ses the complete E7 protein expressed in HeLa cells infected with reco mbinant vaccinia virus. To determine the sensitivity and specificity o f this assay, these results were compared with previous results of the same sera tested by enzyme-linked immunosorbent assay (ELISA; using s ynthetic peptides derived from HPV 16 E7) and radio-immunoprecipitatio n (RIPA) using in vitro translated HPV 16 E7 protein. CIPA (45% positi ves) demonstrated a significant increase in detection rate compared to the peptide-ELISA (30% positives; P = 0.014, chi(2)-test) and only a slight increase compared to RIPA (38% positives; P = 0.204, chi(2)-tes t). Based on the testing of sera from patients with HPV 16 DNA positiv e tumors the specificity and sensitivity of the CIPA were 0.98 and 0.5 9, respectively.