关键词: 细粒棘球绦虫, 天然抗原, 诊断效能, 酶联免疫吸附试验, 棘球蚴病

Abstract: Objective  To evaluate the diagnostic potential of 5 native antigens obtained from Echinococcus granulosus.  Methods  The cyst fluid and protoscoleces were collected from infected livers of slaughtered sheep near Urumqi. The protoscolex somatic soluble antigen（EgPS）, crude hydatid cyst fluid antigen（EgHF）,  partially purified hydatid fluid antigen（Burstein’s antigen, EgBu） and the native antigen B（EgAgB） were prepared. Echinococcus granulosus adult worms were collected from experimentally infected dogs, and then used to prepare adult somatic soluble antigen（EgAS）. Serum samples from patients with cystic echinococcosis（369 cases）, alveolar echinococcosis（14 cases）, cysticercosis（20 cases）, schistosomiasis（50 cases）, paragonimiasis westermani（10 cases）, visceral leishmaniasis（5 cases）, and healthy individuals（366 cases） were examined for the antibodies against 5 native antigens with indirect ELISA. A ROC analysis was performed to determine a cut-off value for each native antigen.  Results  EgPS presented the highest AUCROC（0.958±0.067）, sensitivity（88.7%）, positive predictive value（0.96）, positive likelihood ratio（16.61）, diagnostic efficiency（91.7%）, and odds ratio（138.475）. The specificity of EgBu（96.1%） was the highest, followed by EgAgB（95.7%）, EgPS（94.7%）, EgAS（89.0%）, and EgHF（80.4%）. The Youden index was ranked in order of EgPS＞EgBu＞EgHF＞EgAS＞EgAgB. The antibody reactive intensity of EgBu-ELISA was highest（4.055±1.365） and the EgAS-ELISA was lowest（2.947±1.276）, and there was no significant difference between them（P＞0.05）. The five native antigens presented high cross-reactivity with sera from alveolar echinococcosis（9/14～12/14）and from cysticercosis（8/20～16/20）.  Conclusion  There are significant differences among the five native antigen-ELISA. The EgPS antigen has the best diagnostic performance , which is followed by EgBu and EgAgB.

Key words: Echinococcus granulosus, Native antigen, Diagnostic performance, Enzyme-linked immunosorbent assay, Cystic echinococcosis