Performance evaluation of the chemiluminescence immunoassay for mycoplasma pneumonia antibody detecting

Objective Assessing the detection performance of testing mycoplasma pneumonia(MP)type-specific antibodies by Chemiluminescence immunoassay(CLIA), in order to evaluate the feasibility of screening MP infection by CLIA. Methods Total of 280 cases of respiratory disease patients, 20 examples infected mycoplasma pneumonia and 20 cases health volunteers as the control group were enrolled in this study from August 2016 to October 2017 in the Nanfang Hospital, Southern Medical University, testing MP antibodies by CLIA, Enzyme linked immunosorbent assay(ELISA)and Passive agglutination method(PA) respectively. According to the performance evaluation scheme, we evaluate the performance indexs of detecting MP antibodies by CLIA, including lower limit of detection, intra-batch precision, inter-batch precision, linearity range, clinical coincidence rate and consistency compared with ELISA and PA, and the results were analyzed by EXCEL and SPSS version 22.0. Results MP-IgG CLIA reagent: Limit of blank, Limit of detection and Limit of quantitation were 1.9 AU/ml, 4.5 AU/ml and 5.1 AU/ml respectively; Coefficient Variation (CV) of intra-batch precision in high and low concentration levels were 2.98% and 2.45% respectively; CV of inter-batch precision in high and low concentration levels were 6.44% and 6.83% respectively; both the Linear range and Clinical report range are from 2.0 AU/ml to 253.0 AU/ml; the linear regression equation R2≥0.990 0, 0.85≤b≤1.15. MP-IgM CLIA reagent: CV of intra-batch precision in high and low concentration levels were 2.55% and 2.86% respectively; CV of inter-batch precision in high and low concentration levels were 4.82% and 5.46% respectively. The total clinical coincidence rate of MP-IgG and MP-IgM detected by CLIA were 90.0% and 97.5% respectively. The kappa values of MP-IgG and MP-IgM detected by CLIA and ELISA were 0.763 (P=0.000) and 0.804 (P=0.023) respectively, with Consistent percentage of 88.9% and 91.4% respectively. The kappa value of CLIA and PA was 0.541 (P=0.063) with a consistent percentage of 79.6%. Conclusions The results of study show that detecting MP type-specific antibodies by CLIA meet the prescribed performance indexes. Detecting MP type-specific antibodies by CLIA, which is precise, speedy and automated, could be applied to clinical and replace ELISA and PA, becoming the prior choice in clinical for MP infection screening.(Chin J Lab Med, 2017, 40: 965-969) Key words: Chemiluminescence immunoassay; Mycoplasma Pneumonia; Type-specific antibodies; Performance evaluation; Clinical coincidence rate