应用蛋白质印迹技术提高癌胚抗原对胆道肿瘤的诊断特异性

目的　采用测定胆汁中癌胚抗原 (CEA)含量并结合蛋白质印迹 (Westernblot)技术排除CEA相关物质的干扰 ,提高CEA检测胆道恶性肿瘤的特异性。方法　对临床可疑为胆道恶性肿瘤的患者采用酶联免疫吸附 (ELISA)法测定其血液、胆汁中CEA含量 ,对胆汁CEA含量升高的患者进一步应用Westernblot半干转移技术区分CEA及CEA相关物质。结果　所有CEA含量升高的胆道恶性肿瘤患者的胆汁经Westernblot检测均表现为包含有一条相对分子质量为 2 10 0 0 0的特异条带 ,而胆道良性疾病患者既使其CEA含量高于正常也均不含有该条带。结论　采用Westernblot技术检测胆汁CEA可排除CEA相关物质的干扰 ,提高CEA检测胆道恶性肿瘤的特异性。

Improvement of the diagnosis specificity of biliary cancer with the determination of carcinoembryonic antigen in bile by Western-blot technique

Objective To measure the CEA level in bile and blood samples,further analyze the bile by Western blot technique to eliminate the interference of CEA-related substances to CEA so that to improve the specificity of CEA in the detection of biliary cancer.Methods By using ELISA method,the CEA levels of blood and bile were measured.Semi-dry electrophoretic transfer method of Western blot assay was applied to distiguish CEA and CEA-related substances.Results In biliary cancer the CEA level of bile was significantly higher than that in the blood; In benign disease the CEA level had no difference in bile and blood.All the malignant patients whose CEA level in bile was higher than normal level had a specific band (molecular weight about 210 000),but in all the benign patients no matter how high the CEA level was,they all had no this specific band.Conclusion Using Western blot technique to determing CEA level of bile could eliminate the interference of CEA-related substances to CEA so that to improve the specificity of CEA in the detection of biliary cancer.