抗日本血吸虫SEA特异性IgY应用于循环抗原检测的研究

本研究应用抗日本血吸虫可溶性虫卵抗原(SEA)的鸡卵黄免疫球蛋白(IgY)建立敏感、特异的检测循环抗原的双抗体夹心酶联免疫吸附试验( ELISA).用SEA皮下多点注射法免疫海蓝鸡,水稀释法制备IgY抗体,以辣根过氧化物酶标记纯化的IgY抗体(IgY-E)和兔抗IgG抗体(IgG-E)分别作为检测抗体,IgY抗体和兔抗...

Detection of Circulating Schistosome Antigen with Anti-SEA Specific Egg Yolk Antibody (IgY)

A sensitive and specific double-antibody sandwich enzyme-linked immunosorbent assay （ELISA） was developed to detect circulating schistosome antigen with chicken egg yolk immunoglobulin antibodies （IgY） against soluble egg antigen （SEA）. Hens were subcutaneously immunized with SEA and the crude IgY was extracted from egg yolk by water dilution method. Purified IgY antibodies and rabbit IgG antibodies against S. japonicum were labeled with horseradish peroxidase respectively （IgY-E and IgG-E）. 4 double-antibody sandwich ELISA methods were developed using IgY or IgG as capture antibody and using IgY-E or IgG-E as detecting antibody respectively. The detection limits of SEA of 4 ELISA methods were analyzed. Then human serum from patients and healthy people were detected in parallel by established 4 ELISA methods, including 6 serum samples from acute schistosomiasis patients, 29 from chronic schistosomiasis patients, 118 from healthy people, 9 from clonorchiasis patients, 15 from paragonimiasis patients, and 7 from toxoplasmiasis patients. The results showed that the minimal detectable concentration of SEA was 7.5 ng/ml by IgY based-sandwich ELISA, the sensitivity was higher than IgG based-sandwich ELISA by 4 times. All sandwich ELISA methods showed a sensitivity of 100% for acute schistosomiasis patients, a specificity of 99. 1% for healthy persons; no cross-reaction with Toxoplasmiasis and clonorchiasis; The positive rate of samples from 29 chronic schistosomiasis patients and 15 paragonimiasis patients were 79.3% , 6.7% respectively when using IgY as capture antibody, while the positive rate were 75.8% , 6. 7% and 72.4% , 13.3% when using IgG as capture antibody, IgY-E and IgG-E as detecting antibody respectively, indicating the assay involved the use of IgY was better than that of rabbit anti-schistosoma IgG. The novel double-antibody sandwich ELISA assay using anti-SEA IgY appears to be sensitive and specific for detection of circulating schistosome antigens. It is the promising assay for immunodiagnosis of S. japonicum infections.