Comparison and harmonization assessment of mutual among four different immunoassay systems in CA19-9 test / 中华检验医学杂志

ABSTRACT

Objective To investigate the differences and harmonization of immunoassay systems in detecting CA19-9 and to assess the possibility of mutual recognition in different laboratories.Methods Data were collected and analyzed from External Quality Assessments (EQA) of NCCL(Lots200811-201215) and ZJCCL(Lots080309-120211).120 fresh serum with different concentrations of CA19-9 were collected.The CA19-9 results of healthy people were also collected from September 2010 to March 2012.Four kinds of stable immunoassay systems were involved in our research,including Abbott Architect i2000,Beckman UniCel DxI 800,Roche E170 and Siemens ADVIA Centaur XP.The differences among four system groups were calculated with the EQA data.The fresh serum comparisons were also performed following the guideline of CLSI EP9-A2 The 95％ confidence interval of each immunoassay system was calculated.Comparisons were made by scatter diagrams and weighted regression.Results Both EQA of NCCL and ZJCCL showed better correlation coefficients and larger bias (bw ranged from 1.340 to 4.683) than in fresh serum comparisons.Although the correlation coefficients were all unsatisfactory,the bw were all close to 1 in fresh serum comparisons.When the recommended serum concentration of 27 U/ml was used,the biases were Abbott-Roche-6.41％,Beckman-Roche-5.07％,Siemens-Roche 13.15％,Beckman-Abbott 2.46％,Siemens-Abbott 22.52％ and Siemens-Beckman 39.66％,respectively.Differences of 95％ confidence intervals were statistically significant among parts of the immunoassay systems.Conclusions Only in the lower concentration can CA19-9 results be mutual recognized among four different immunoassay systems,there will be larger differences and risks in the higher concentration.