[The analysis to data from Chinese Rheumatism Data Center external quality assurance program for autoantibodies in 2021].

ABSTRACT

To evaluate the data obtained from the external quality assurance program initiated by Chinese Rheumatism Data Center (CRDC-QAP) for autoantibodies detection in 2021, so as to assess the consensus and differences in cross-laboratory testing to autoantibodies in China. This is a retrospective study. After collecting data from the first half year (from May 15th to July 10th) and the second half year (from August 15th to November 19th) of CRDC-QAP program for autoantibody detection in 2021, it firstly analyzed the qualitative consensus of the cross-laboratory results. Secondly, it compared the positivity grade of numeric results according to the Sample to cut-off ratio (S/CO ratio) calculation. Finally, the mean and coefficient variation (CV) of numeric results from three major manufacturers were calculated. A total of 303 and 332 clinical labs voluntarily participated in the first half year and the second half year of CRDC-QAP program for autoantibody detection in 2021, respectively. Except for anti-ß2 glycoprotein type I (aß2-GPI) IgM, the cross-laboratory consensus of qualitative results for the other autoantibodies is greater than 96%. As for anti-cyclic citrullinated peptide antibody (anti-CCP) and anti mitochondrial antibody-M2 (AMA-M2), the numeric results from more than 90% laboratories showed the same positivity grade. More than 50% of laboratories used chemiluminescence immunoassay (CLIA) for quantitative evaluation of autoantibody. The CV of numeric results from different manufacturers showed certain differences(P<0.01) with the range from 0 to 238%. Although high consensus can be observed in term of qualitative result for autoantibody detection in cross-laboratory, there are still certain differences in numeric results in term of positivity grade and manufacturer-based CV.