Alternative antibody for the detection of CA125 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access OV Monitor assay on the UniCel Dxl 800 Immunoassay System.
BACKGROUND
Cancer antigen CA125 is known as a valuable marker for the management of ovarian cancer.


METHODS
The analytical and clinical performance of the Access OV Monitor Immunoassay System (Beckman Coulter) was evaluated at five different European sites and compared with a reference system, defined as CA125 on the Elecsys System (Roche Diagnostics).


RESULTS
Total imprecision (% CV) of the OV Monitor ranged between 3.1% and 8.8%, and inter-laboratory reproducibility between 4.7% and 5.0%. Linearity upon dilution showed a mean recovery of 100% (SD + 8.1%). Endogenous interferents had no influence on OV Monitor levels (mean recoveries: hemoglobin 107%, bilirubin 103%, triglycerides 103%). There was no high-dose hook effect up to 27,193 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access OV Monitor and Elecsys CA125 (R = 0.982, slope = 0.921, intercept = +1.951). OV Monitor serum levels were low in healthy individuals (n = 267, median = 9.7 kU/L, 95th percentile = 30.8 kU/L), higher in individuals with various benign diseases (n = 549, medians = 10.9-16.4 kU/L, 95th percentiles = 44.2-355 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 12.4-445 kU/L; 95th percentiles = 53.4-4664 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the OV Monitor was found for ovarian cancer [area under the curve (AUC) 0.898]. Results for the reference CA125 assay were comparable (AUC 0.899).


CONCLUSIONS
The Access OV Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with Elecsys CA125. The best diagnostic accuracy for the OV Monitor was found in ovarian cancer. Our results also suggest a clinical value of the OV Monitor in other cancers.
Holdenrieder
Stefan
S
Institut für Klinische Chemie, Klinikum der Universität München, Munich, Germany.
Molina
Rafael
R
Gion
Massimo
M
Gressner
Axel
A
Troalen
Frédéric
F
Auge
Jose Maria
JM
Zancan
Matelda
M
Wycislo
Matthias
M
Stieber
Petra
P
D000906:Antibodies / Q000097:blood*; D018394:CA-125 Antigen / Q000032:analysis*; D005060:Europe; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D010051:Ovarian Neoplasms / Q000175:diagnosis*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000906:Antibodies; D018394:CA-125 Antigen