原发性胆汁性肝硬化特异性AMAM2抗体在5 011名体检者中的筛查分析

目的：在健康体检者中筛查原发性胆汁性肝硬化(PBC)特异性AMAM2抗体，并对AMAM2抗体阳性者进行分析。方法：设计克隆表达了一抗原蛋白三联体，命名为BPO，它包含了AMAM2抗体识别的人源BCOADC-E2、PDC-E2和OGDC-E2的抗原表位片断。利用纯化的重组BPO，建立了PBC特异性免疫学诊断方法。ELISA法筛查5011名体检者，进一步分析AMAM2抗体阳性者的生化和免疫指标。超声检查或ERCP检查排除非PBC异常。结果：5011名体检者中有8名AMAM2抗体阳性(阳性率0.16％、)，其中7名为女性，1名为男性，年龄均在40岁以上。4名AMAM2抗体阳性者有不明原因的碱性磷酸酶和γ-谷氨酸转肽酶的增高，虽无PBC的临床症状(如疲劳，皮肤瘙痒或黄疽)，但其中有3名符合美国肝脏病学会推荐的PBC诊断标准。有两名行肝穿刺检查，均符合PBC病理学特征。结论：无症状PBC患者在中国并不少见。

Measurement of M2 autoantibodies in early diagnosis of primary biliary cirrhosis

Objective To investigate the presence of M2 antibodies sepecific to primary biliary cirrhosis (PBC) in Chinese symptomatic population and identified patients in the early stage of disease. Methods A triple hybrid clone, designated as BPO was designed, which coexpresses the three immunodominant lipoyl domains of PDC-E2, BCOADC-E2 and OGDC-E2 from human sources and established the specific immunological methods with purified BPO to detect the M2 antibodies. ELISA were performed in 5 011 persons who took an annual physical examines. Full biochemical and immunological data were obtained from M2-positive persons. In addition, ultrasonography (US) or endoscopic retrograde cholangio-pancreatography (ERCP) were required to exclude any disorders other than PBC. Results M2 antibodies were detected in 8 (0.16%) of the 5 011 subjects studied. Of the 8 subjects, 7 were female and 1 was male. An unexplained increase of serum alkaline phosphatase and gamma glutamyl transpeptidase values was detected in 4 M2-positive subjects, 3 of which fulfilled the diagnostic criteria voted by the American association for the study of liver diseases, even they had no symptoms of PBC (such as fatigue, pruritus or jaundice). Liver biopsy was performed in two M2-positive subjects. The histology was compatible with PBC in both cases. Conclusion Symptomless PBC is much more common in China than that has been supposed.