[Evaluation of diagnostic efficacy of digital liquid chip method for detection of specific antineutrophil cytoplasmic antibodies].

To explore the clinical diagnostic efficacy of antineutrophil cytoplasmic antibody associated vasculitis (AAV) by comparing the consistency and coincidence rate of serum anti-myeloperoxidase (MPO) antibody and anti-protease 3 (PR3) antibody detected by digital liquid chip method (DLCM) and enzyme-linked immunosorbent assay (ELISA). To provide reference for the selection of detection methods of anti-MPO antibody and anti-PR3 antibody in clinical laboratory. This study is a cross-sectional study, a total of 307 cases of antineutrophil cytoplasmic antibodies were detected in the Department of Clinical Immunology, West China Hospital of Sichuan University from January to March 2021. The serum samples and related clinical information were collected. At the same time, the levels of anti-MPO antibody and anti-PR3 antibody in serum samples were detected by ELISA and DLCM, indirect immunofluorescence (IIF) was used to re-test the differential samples between the two methods. SPSS 26.0 was used to analyze the test results, Cohen's kappa coefficient analysis was used to compare the consistency of the two methods, and paired chi-square test was used to compare the sensitivity and specificity of the two methods to AAV. The results showed that the positive cases of anti-MPO antibody detected by ELISA and DLCM were 63 and 44, and the negative cases were 244 and 263; the positive cases of anti-PR3 antibody detected by ELISA and DLCM were 34 and 28, and the negative cases were 273 and 279. The results of anti-MPO antibody and anti-PR3 antibody detected by the two methods had good consistency and coincidence rate, in which the total coincidence rate of anti-MPO antibody was 92.51%, the positive coincidence rate was 66.67%, and the negative coincidence rate was 99.18%. The results of consistency analysis showed that kappa=0.741 had well consistency. The total coincidence rate of anti-PR3 antibody is 96.74%, the positive coincidence rate is 76.47%, and the negative coincidence rate is 99.27%. The consistency analysis results show that kappa=0.821 had strong consistency. The results of IIF re-test of differential samples showed that the coincidence rate between DLCM and IIF was higher. The results of comparative analysis of anti-MPO antibody and anti-PR3 antibody showed that the specificity of DLCM was better than that of ELISA, and its sensitivity was lower than that of ELISA. In conclusion, the results of anti-MPO antibody and anti-PR3 antibody detected by DLCM were consistent with those of ELISA. In the combined detection of anti-MPO antibody and anti-PR3 antibody, the specificity of DLCM is better than that of ELISA.通过比较数码液相芯片法（digital liquid chip method，DLCM）检测血清抗髓过氧化物酶（myeloperoxidase，MPO）抗体和抗蛋白酶3（proteinase 3，PR3）抗体与酶联免疫吸附法（enzyme-linked immunosorbent assay，ELISA）检测结果的一致性与符合率，探讨其对抗中性粒细胞胞浆抗体相关血管炎（antineutrophil cytoplasmic antibodies associated vasculitis，AAV）的临床诊断效能，为临床实验室抗MPO抗体和抗PR3抗体检测方法的选择提供参考。本研究为横断面研究，选取2021年1—3月在四川大学华西医院实验医学科临床免疫室检测抗中性粒细胞胞浆抗体的样本307例，收集其血清样本及相关临床信息，同时采用ELISA和DLCM平行检测血清样本中抗MPO抗体和抗PR3抗体水平，使用间接免疫荧光法（indirect immunofluorescent，IIF）就两种方法学差异样本进行复测验证。采用SPSS 26.0对检测结果进行统计分析，运用Cohen′s kappa系数分析比较两种方法检测结果的一致性，运用配对χ²检验比较两种方法检测结果对AAV的敏感度和特异度。结果显示，采用ELISA和DLCM两种方法平行检测抗MPO抗体阳性例数分别为ELISA 63例和DLCM 44例，阴性例数分别为ELISA 244例和DLCM 263例；检测抗PR3抗体阳性例数分别为ELISA 34例和DLCM 28例，阴性例数分别为ELISA 273例和DLCM 279例。两种方法检测抗MPO抗体和抗PR3抗体的检测结果均有良好的一致性与符合率，其中抗MPO抗体总符合率为92.51%，阳性符合率为66.67%，阴性符合率为99.18%，一致性分析结果显示 kappa=0.741，具有较强一致性；抗PR3抗体总符合率为96.74%，阳性符合率为76.47%，阴性符合率为99.27%，一致性分析结果显示 kappa=0.821，具有很强一致性。IIF复测差异样本结果均显示DLCM结果与IIF结果符合率更高。抗MPO抗体和抗PR3抗体联合检测性能比较分析结果显示，DLCM的特异度优于ELISA，其敏感度较ELISA偏低。综上，DLCM检测抗MPO抗体和抗PR3抗体检测结果与ELISA结果比较均具有良好的一致性与符合率。在联合检测抗MPO抗体和抗PR3抗体时，DLCM特异度优于ELISA。.