细粒棘球蚴粗抗原的免疫纯化方法及其在免疫诊断中的应用

A Method of Immunological Purification of Echinococcus granulosusAntigens and its Application in Immunodiagnosis of Echinococcosis

采用免疫过筛法将细粒棘球蚴囊液粗抗原 (Eg CF)和头节抗原 (Eg P)与正常人混合血清中杂抗体结合而除去产生非特异反应的粗抗原部分 ,得到部分纯化的抗原 Eg CF2、Eg P2 ,纯化前后的抗原在酶联免疫吸附试验 (EL ISA)及斑点免疫结合试验 (DIBA )中对 45例细粒棘球蚴病 (CE)的诊断阳性率分别为 :Eg CF 93.3%、Eg P 95 .6 %、Eg CF2 91.1%、Eg P2 93.3% ,它们的敏感性无显著差异 (P>0 .0 5 )。虽然纯化后的 Eg CF2和 Eg P2在泡球蚴病和囊虫病中与纯化前的交叉反应程度在统计学上有显著差异 (P<0 .0 5 ) ,但正常健康对照及其它寄生虫病人中较纯化前 EL ISA的消光值明显降低 (P<0 .0 1) ,DIBA的背景明显清晰易辨 ,其中 Eg CF2的假阳性和可疑结果由纯化前 11.1%减少到 2 .8% ,Eg P2假阳性结果由纯化前 13.9%减少到 2 .8% ,显然经纯化后的抗原特异性得到显著提高 ,且明显减少了非特异性反应 ,从而提高了包虫病斑点免疫结合试验和酶联免疫吸附试验的准确性。

The partial pruified antigens of EgCF 2 and EgP 2 have been gained by using an immunofiltration method combained the crude antigens of EgCF and EgP with normal human sera to eliminate the cross reactive fractions. The dot immunoassay (DIBA) and enzyme linked immunosorbent assay (ELISA) have been performed with sera samples of 45 cases with cystic echincoccosis (CE), 22 cases of alveolar echinococcosis (AE), 10 cases with cysticercosis and 26 cases with other parasitic diseases. 32 normal sera were tested as control. The seropositive rates of crude antigens were 93.3%~95.6% in CE, 91.1%~93.3% in AE, 70%~80% in cysticercosis and 11.5% in other parasitic diseases. The false positive rates in controls were 11.1%~13.9%. But the seropositive rates with purified antigens EgCF 2 and EgP 2 were 91.1%~93.3% in CE, 81.8%~86.3% in AE, 60%~70% in oysticercosis and 3.8% in other parasitic diseases respectively. The false positive rate was 5.6% in the control. After purification, the specificity of the antigen has been obuiously increased and the nonspecific reaction reduced evidently.