酶联免疫吸附试验在自身免疫溶血性贫血诊断中的应用

The application of ELISA in the diagnosis of autoimmune hemolytic anemia

目的建立了竞争性酶联免疫吸附试验（ELISA），定量检测红细胞结合IgG（EBIgG），并观察该方法在自身免疫溶血性贫血（AIHA）诊断中的应用价值。方法应用该竞争性ELISA和常规直接抗人球蛋白试验（DAT）研究了72例AIHA、28例系统性红斑狼疮（SLE）及血液系统肿瘤、31例其他类型贫血、22例特发件血小板减少性紫癜（ITP）患者和46名健康志愿者的EBIgG。结果DAT IgG阳性的AIHA患者，ELISA检测均为阳性，且结果[（131．4±112．2）fg／10^3红细胞]明显高于正常对照组[（19．8±11．4）fg／10^3红细胞，P〈0．001]：DAT IgG阴性（C3型）的AIHA患者中，ELISA检测的阳性率为52．9％，EBIgG水平[（42．6±29．4）fg／10^3红细胞]亦明显高于正常对照组（P〈0．001）：SLE及血液系统肿瘤患者中，ELISA检测的阳性率为21．4％；而DAT IgG阴性的其他贫血和ITP患者，ELISA检测均为阴性。结论竞争性ELISA检测EBIgG是一种灵敏并客观的方法，对提高AIHA和其他免疫性溶血性贫血的实验诊断水平及指导临床治疗有重要价值。

Objective To establish a competitive enzyme-linked immunosorbent assay（ELISA）for quantitative measurement of erythrocyte-bound IgG （EBIgG） and to observe its clinical significance in autoimmune hemolytic anemia （AIHA）. Methods Competitive ELISA and a routinely used direct antiglobulin test （DAT） were used to study EBIgG in 72 cases of AIHA, 28 cases of systemic lupus erythematosus （SLE） and tumor of blood system, 31 cases of other anemia, 22 cases of idiopathic thrombocytopenic purpura （ITP） and 46 healthy volunteers. Results The results by ELISA in DAT IgG-positive patients with AIHA were all positive, and the data [（131.4±112.2）fg/10^3 erythrocytes] were notably higher than those in control subjects [（19.8±11.4）fg/10^3 erythrocytes]（P〈0.001）. In DAT IgG-negative patients with AIHA （C3 type）, the positive percentage by ELISA was 52.9%, and the data [（42.6±29.4）fg/10^3 erythrocytes] were also remarkably higher than those in control subjects（P〈0.001）. In cases of SLE and tumor of blood system, the positive percentage by ELISA was 21.4%. The results by ELISA in DAT IgG-negative patients with other anemia and ITP were all negative. Conclusions Competitive ELISA is a sensitive and objective method for measurement of EBIgG. It is of importance to enhance the diagnostic level of AIHA and other immune hemolytic anemias, and give a guide to clinical treatment.