人颚口线虫病两种免疫诊断方法的建立和应用

目的 建立敏感和特异的人颚口线虫病免疫诊断方法,并加以应用.方法 以颚口线虫Ⅲ期幼虫可溶性蛋白为抗原,采用Western印迹技术检测颚口线虫特异的相对分子质量为21 000和24 000抗原蛋白条带,用ELISA半定量检测抗颚口线虫IgG抗体.结果 Western印迹法检测8份颚口线虫患者血清,均可见相对分子质量为24 000的条带,7份可见相对分子质量为21 000的条带；30份疑似患者血清共有18份可见相对分子质量为17 000～26 000之间的特异性条带；检测25份健康人血清和25份曼氏裂头蚴病、广州管圆线虫病、肺吸虫病、囊虫病、血吸虫病等其他蠕虫病患者的血清样本,未见该条带反应.ELISA检测8例颚口线虫患者血清IgG抗体均为阳性,检测50例健康人血清,特异性为98.0％（49/50）,与曼氏裂头蚴病、广州管圆线虫病、肺吸虫病、囊虫病、血吸虫病等其它蠕虫病患者血清的交叉反应率分别为20.0％（6/30）、14.3％（3/21）、6.7％（2/30）、3.3％（1/30）和3.3％（1/30）.30例颚口线虫疑似患者,ELISA检测均阳性,Western印迹法检测18例阳性.结论 免疫印迹检测颚口线虫特异的相对分子质量为21 000和24000抗原条带特异性强,适用于疑似患者鉴别诊断,但操作复杂、费时,技术要求高；ELISA检测抗颚口线虫IgG抗体的敏感性高、操作流程半自动化,适合门诊患者筛检和人群流行病学调查,但其与曼氏裂头蚴病、广州管圆线虫病等其它蠕虫患者血清交叉反应率高.

Establishment of two immunodiagnostic methods for human gnathostomiasis and their application

Objective To establish sensitive and specific immunodiagnostic methods for gnathostomiasis and to use them in practice.Methods The soluble protein of the third-stage larvae of gnathostoma was used as antigen.The Western blot was used to detect the specific antigen recognition bands with relative molecular mass （Mr） 24 000 and 21 000.An indirect ELISA was used as semi-quantitative method to detect specific IgG antibodies in serum samples of patients with gnathostomiasis.Results The immunoblotting results showed that specific antigen recognition bands with Mr 24 000 were detected in all serum samples from 8 positive cases of gnathostomiasis,among which 7 had specific antigen recognition bands with Mr 21 000.Of 30 suspects,18 were detected specific antigen recognition bands between Mr 17 000 and 26 000.Western blotting was also used to detect 25 serum samples from healthy subjects and 25 serum samples from other patients with sparganosi mansoni,angiostrongyliasis cantonensis,paragonimiasis,cysticercosis,or schistosomiasis and neither of the 2 specific antigen recognition bands were observed in the two groups.ELISA results showed IgG positive in all 8 serum samples of patients with gnathostomiasis.The specificity of ELISA for the detection of IgG antibody of gnathostomiasis was 98.0% （49/50）.However,the cross-reaction rate with serum samples from patients with sparganosi mansoni,angiostrongyliasis cantonensis,paragonimiasis,cysticercosis,or schistosomiasis were 20.0%（6/ 30）,14.3%（3/21）,6.7%（2/30）,3.3%（1/30）,and 3.3%（1/30）,respectively.ELISA results were all positive in 30 suspects,while the Western blot had 18 positive results.Conclusions The Western blot method to separate the specific antigen of gnathostomasis by Mr 24 000 and 21 000 is with good specificity and can be used for differential diagnosis of suspects,but this method is complicated and time-consuming and also requires high specification.ELISA to detect serum specific IgG antibodies with semi-automatic operation procedures has good sensitivity and can be used for screening outpatients and epidemiological survey,but its cross-reaction rate with other helminthiasis is high.