ELISA法检测IgA肾病患者血清β_2-GPI/LDL复合物

Detection of serum level of β_2-glycoprotein I/LDL complexes in SLE patients with ELISA

目的建立人血清β2-糖蛋白Ⅰ/低密度脂蛋白(β2-GPI/LDL)复合物ELISA检测法,探讨其对IgA肾病的诊断价值。方法建立以抗人β2-GPI抗体为包被抗体、酶标记抗apoB为检测抗体的β2-GPI/LDL ELISA检测法,对50例IgA肾病患者和50例健康对照者检测分析。结果建立的β2-GPI/LDL ELISA检测法灵敏度0.25 U/m l,批内、批间变异系数为5.73%和10.67%,参考范围(0.66±0.17)U/m l。IgA肾病组β2-GPI/LDL水平显著高于对照组[(1.27±0.23)U/m l vs(0.66±0.17)U/m l,P<0.0001]。敏感性86%,特异性为100%。结论β2-GPI/LDL以健康对照组x-+2s即1.0 U/m l为cut off值,对IgA肾病有较高的敏感性与特异性,提示其有潜在的临床诊断价值。

Objective To develop a sandwich ELISA for measuring serum β2-GPI/LDL concentration, and to explore its value in diagnosing IgA nephropathy. Methods ELISA was established using rabbit anti-human β2-GPI as the capture antibody and using polyclonal antibody against apoB enzyme conjugate as detecting antibody. The concentrations of β2-GPI/LDL complexes were measured in 50 patients with IgA nephropathy and in 50 healthy controls. Results The sensitivity of the ELISA was 0.25 U/ml. Mean intra-assay and inter-assay coefficients of variation of the assay were 5.73% and 10.67%, respectively. Reference range of normal individuals was 0.66 ± 0.17 U/ml （x ±s）. Serum β2-GPI/LDL concentrations in IgA nephropathy were significantly higher than those of controls [ （ 1.27 ±0.23） U/ml vs （0.66 ± 0.17） U/ml,P 〈0. 0001 ]. Forty three patients （sensitivity 86% ） had elevated β2-GPI/LDL,whereas none of healthy controls had high β2-GPI/LDL （ specificity 100% ）. Conclusions Two SD above the mean OD of 50 samples from healthy controls was regarded as 1.00 U/ml （cut-off value）. β2-GPI/LDL exhibited high sensitivity and specificity for SLE, suggesting its potential clinical value.