Comparative study on two chemiluminescence immunoassay systems in detecting carbohydrate antigen 19-9

Objective To compare the results carbohydrate antigen 19-9(CA19-9)determined by two different chemiluminescence immunoassay(CLIA)systems(A:Cobas 411,B:Beckman Dxi800).Methods Referring to the EP9-A2document,40serum samples from different patients were collected and CA19-9levels were tested by the 2 different CLIA systems respectively.The collected data were processed by statistical analysis.A system was use as standard system to evaluate the acceptability of B system.Results There were no significant different between two different CLIA systems in rank sum test(P0.05).Linear regression equations that B system for Asystem were YB =1.0812 XA-4.848 4,r2=0.962 2.In Specified concentration 25U/mL and 250U/mL of CA19-9,B relative bias is 11.28%and 6.00%.By CA19-9biological variation in the best total allowable error(TEa)22.1%for the standard. System B was completely acceptable.Conclusion There is comparability of two CLIA systems in the evaluation of clinical acceptability of CA19-9and the difference between them is acceptable.