Technical evaluation of three second generation CA 125 assays.
The analytical performance of five CA 125 assays was studied using samples from apparently healthy women (n = 28) and from a group of patients with gynaecological malignancies (n = 260). Investigations were carried out on two homologous sandwich assays using the monoclonal antibody OC 125 (LIA-mat I and IRMA-mat I) and three heterologous assays using the monoclonal antibodies OC 125 and M11, both directed against the carcinoantigen CA 125 (LIA-mat CA 125 II, IRMA-mat CA 125 II, Centocor CA 125 II). The precision of the LIA-mat CA 125 II was better than that of the previously used LIA-mat I, the intra-assay coefficients of variation being 6.5% and 11.6% respectively. Using the new generation CA 125 II assays, only 0.5% of the duplicate measurements had to be rejected. The inter-assay coefficient of variation of the automated LIA-mat CA 125 II ranged from 7.1% to 11.2% while the IRMA-mat CA 125 II inter-assay CV ranged from 11.6% to 13.9%. Serum EDTA or heparin plasma did not give significantly different results. A carry-over of 0.02% was observed using the LIA-mat S 300 system. A high dose hook effect may be observed with concentrations over 20000 kU/l. All assays showed excellent linearity, and there was a good correlation between the assays.
Algemeen Klinisch Laboratorium, Het Nederlands Kanker Instituut/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam, Nederland.
J M
JM
Bonfrer
A W
AW
Baan
E
E
Jansen
D
D
Lentfer
P
P
Kenemans
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D005260:Female; D005833:Genital Neoplasms, Female / Q000175:diagnosis*; D006801:Humans; D015592:Immunoradiometric Assay / Q000379:methods*; D008875:Middle Aged; D012015:Reference Standards; D012044:Regression Analysis; D015203:Reproducibility of Results
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor