细粒棘球蚴重组抗原B 8-kDa亚单位1对囊型包虫病的血清学诊断价值

Serological diagnosis of cystic echinococcosis using recombinant antigen B 8-kDa-subunits1 of Echinococcus granulosus

目的通过基因工程技术获得细粒棘球蚴抗原B8-kDa亚单位1重组蛋白(rEgAgB8/1),探讨其对囊型包虫病(CE)的血清学诊断价值。方法将构建的rEgAgB8/1原核表达质粒(pET32b-rEgAgB8/1)转化至E.coli BL-21(DE3)中,用IPTG诱导表达,经亲和层析纯化获得高纯度rEgAgB8/1,以rEgAgB8/1为抗原,应用ELISA和Immuno blotting方法对31例手术确诊的囊型包虫病病人血清进行了回顾性检测与分析。结果ELISA和Immuno blotting方法检测CE病人血清阳性率均为90.3%(28/31),3例血清学检测阴性的CE病人均为初次诊断为CE及单纯性肝脏单发感染的病人;血清抗体水平随着病人棘球蚴囊数目增加而有所增加,棘球蚴囊的数目与血清抗体水平的比较用单因素方差分析有显著性差异(F=5.06,P=0.0142),1个囊与2个囊/3个囊组间血清抗体水平有显著差异,2个囊与3个囊组间差异无统计学意义。结论rEgAgB8/1重组蛋白抗原对囊型包虫病有较高的血清学诊断价值,多囊型包虫病人血清抗体水平高于单囊型包虫病人。

To obtain Echinococcus granulosus recombinant antigen B 8-kDa-subunitsl （rEgAgB8/1） through gene engineering technique and evaluate its usefulness for serodiagnosis of human cystic echinococcosis, a previously constructed rEgAgB8/1-prokaryotic expression plasmid vector （pET32b-rEgAgB8/1）was transformed into E. coli BL-21 （DE3）. Protein expression was induced with IPTG and the expressed rEgAgB8/1 was purified using His-tagged affinity chromatography column. Thirty one serum samples from surgically confirmed patients with cystic echinocoecosis （CE） were analyzed by serology in ELISA and immunoblotting using rEgAgBS/1 as diagnostic antigen, and the results were analyzed by retrospective studies. 28 （90.3 700 ） of 31 serum samples were found to be positive both in rEgAgB8/1-ELISA and rEgAgB8/1-immunoblot assary, the remaining 3 sero-negative serum samples were from CE patients with single cyst in liver diagnosed for the first time. The titer of serum antibody seemed to be increased through the increase of number of hydatid cysts formed （F= 5.06,P= 0. 0142）, and the antibody level in serum samples from patients with single cyst was lower than that in with 2 and 3cysts, howere there was no apperant discrepancy of serum antibody titer between patients with 2 cysts and 3 cysts. It is apparent that rEgAgB8/1 is highly useful for serodiagnosis of human cystic echinococcosis. The titer of serum antibody against rEgAgB8/1 is higher in CE patients with multi-cysts than in with that of single cyst.