Technical and clinical comparison of two fully automated methods for the immunoassay of CA 125 in serum

The sensitivity and precision of two fully automated enzyme immunoassays, a chemiluminescent enzyme immunoassay (CLEIA) and an enzyme-linked immunosor bent assay (ELISA), for the determination of the ovarian carcinoma antigen CA 125 were evaluated by comparison with an immunoradiometric assay (IRMA). Sera were obtained from patients with ovarian carcinoma (N = 28 before tre atment and N = 24 after treatment), digestive system cancer (N = 21 before treatment) and from healthy women (N = 90). The CLEIA showed a good agreeme nt with the IRMA. in terms of the positivity rate, accuracy and assay linea rity, whereas the ELISA gave some false positive results. The mean value of CA 125 in the sera of healthy women was 14, 16 and 20 U/ml determined usin g the CLEIA, IRMA and ELISA procedures with standard deviations (SD) of 6.9 , 7.3 and 8.8 U/ml, respectively. Both the reproducibility and precision of the CLEIA with coefficients of variation (CV) of 4.6% intra-assay and 7.6% inter-assay were better than those of the ELISA with CV of 6.2% intra-assa y and 15.2% inter-assay (N = 16). We conclude that the CLEIA is the prefera ble method for CA 125 determinations and the diagnosis of ovarian carcinoma . (C) 1999 Elsevier Science B.V. All rights reserved.