葡萄糖-6-磷酸异构酶免疫复合物检测方法的建立及其在类风湿关节炎诊断中的应用

目的建立葡萄糖-6-磷酸异构酶(G6PI)免疫复合物测定方法,初步探讨其与类风湿关节炎(RA)发病机制的关系及其对RA辅助诊断、病情监测的作用。方法建立C1q抗体捕获ELISA方法,并对311例血清标本(RA患者176例、其他免疫疾病患者35例和健康体检者100例)和44例关节液标本(RA患者33例、非RA关节疾病患者11例)中的G6PI/G6PI抗体/C1q免疫复合物水平进行检测。结果以波长450 nm吸光度值(A_(450nm))表示复合物含量,176例RA患者血清中G6PI免疫复合物为0.918±0.507,显著高于其他免疫疾病对照组(0.746±0.399)和健康对照组(0.696±0.362),P0.01;而两对照组间差异无统计学意义。RA活动组为1.045±0.529,显著高于非活动组(0.764±0.436),P0.01。以健康对照组A_(450nm)值建立正常参考区间,结果G6PI免疫复合物对RA诊断的敏感性和特异性分别为60.2%和67.4%,活动期RA的阳性率为74%,显著高于非活动期(43.7%)。33例RA患者、11例其他关节疾病患者关节液中G6PI免疫复合物A_(450nm)分别为0.835±0.497和0.596±0.132,RA患者组显著高于其他关节病组,P0.05。结论 RA患者血清和关节液G6PI免疫复合物含量增高,且增高程度与RA病情活动相关;G6PI免疫复合物可能在RA发病中起重要作用,且与疾病的活动性密切相关。

The detection and clinical application of glucose-6-phophate isomerase-containing complex in rheumatoid arthritis

Objective To establish a method to measure glucose-6-phophateisomerase(G6PI)-containing complex in serum and synovial fluid of the patients with rheumatoid arthritis(RA) by enzyme-linked immunosorbent assay(ELISA) and to study the mechanism of G6PI/G6PI Ab-containing complex in the development of RA. Methods A Clq antibody capture ELISA was devel-oped to detect Clq/G6PI/G6PI Ab-containing immune complexes. The level of G6PI/G6PI Ab-containing complex in serum of 176 patients with RA,35 with non-RA and 100 healthy donors and 44 synovial fluid of 33 patients with RA and 11 cases with non-RA were tested. Results The values of A450nm of the G6PI/G6PI Ab-containing complex in serum of 176 RA patients,35 non-RA pa-tients and 100 healthy controls were 0. 918±0. 507,0. 746±0. 399 and 0. 696±0. 362 respectively. The level of G6PI/G6PI Ab-containing complex in serum were abnormally increased in RA patients compared with healthy controls(P<0. 01). Among the RA patients, the active phase and the inactive phase were 1. 045±0. 529 and 0. 764±0. 436,respectively. Compared with RA inactive group, they were significantly higher in serum of active group(P<0.01). With the values of A_(450nm)of the healthy control subjects as confidence in terval, the value of the cut-off was 0. 755. The sensitivity and specificity of G6PI in the RA patients were 60. 2% and 67.4% respectively. The values of A_(450nm)of the G6PI/G6PI Ab-containing complex in synovia of 33 RA patients and 11 non-RA patients were 0. 835±0. 497 and 0. 596±0.132,respectively. In synovia, the level of G6PI/G6PI Ab-containing complex were significantly higher in RA patients than that in non-RA patients(P<(0.05). Conclusion The increased expression of G6PI/G6PI Ab-containing complex may play a pathological role in the development of RA,and it may be correlated with the activity of RA.