Lenzi M, Manotti P, Muratori L, Cataleta M, Ballardini G, Cassani F, Bianchi F B
Cattedra di Medicina Interna 2, Policlinico S Orsola, Università di Bologna, Italy.
Gut. 1995 May;36(5):749-54. doi: 10.1136/gut.36.5.749.
Within the multiform liver/kidney microsomal (LKM) family, a subgroup of sera that reacts with a liver cytosolic (LC) protein has been isolated and the new antigen-antibody system is called LC1. Unlike LKM antibody type 1 (anti-LKM1), anti-LC1 is said to be unrelated to hepatitis C virus (HCV) infection and has therefore been proposed as a marker of 'true' autoimmune hepatitis type 2. Altogether 100 LKM1 positive sera were tested by immunodiffusion (ID). Twenty five gave a precipitation line with human liver cytosol; 17 of the 25 also reacted with rat liver cytosol. Thirteen of the 25 sera were anti-HCV positive by second generation ELISA: anti-HCV positive patients were significantly older (p < 0.001) and tended to have less active disease. No difference in anti-LC1 titre or ID immunoreactivity was found between anti-LC1/anti-HCV positive and anti-LC1/anti-HCV negative cases. In Western blotting experiments, 14 of 24 ID positive sera recognised a 58 kD protein of the human cytosolic fraction and 11 gave a similar reactivity when tested with human microsomes, suggesting the presence of the LC1 target antigen also in the microsomal preparation. Western blotting reactivity was similar for both anti-HCV positive and negative sera. These data confirm the existence of the LC1 antigen-antibody system that partially overlaps with LKM1, and that it is an additional marker of juvenile autoimmune hepatitis type 2. It does not, however, discriminate between patients with and without HCV infection.
在多形性肝/肾微粒体（LKM）家族中，已分离出一组与肝细胞质（LC）蛋白发生反应的血清亚群，这种新的抗原-抗体系统被称为LC1。与1型LKM抗体（抗-LKM1）不同，抗-LC1据说是与丙型肝炎病毒（HCV）感染无关，因此被提议作为“真正的”2型自身免疫性肝炎的一个标志物。总共100份抗-LKM1阳性血清通过免疫扩散（ID）进行检测。25份血清与人类肝细胞质产生沉淀线；这25份血清中的17份也与大鼠肝细胞质发生反应。25份血清中有13份通过第二代酶联免疫吸附测定法检测为抗-HCV阳性：抗-HCV阳性患者年龄显著更大（p<0.001），且疾病活动度往往较低。抗-LC1/抗-HCV阳性和抗-LC1/抗-HCV阴性病例之间在抗-LC1滴度或ID免疫反应性方面未发现差异。在蛋白质印迹实验中，24份ID阳性血清中的14份识别出人类细胞质部分的一种58kD蛋白，并且11份在用人类微粒体检测时产生了类似的反应性，这表明微粒体制剂中也存在LC1靶抗原。抗-HCV阳性和阴性血清的蛋白质印迹反应性相似。这些数据证实了LC1抗原-抗体系统的存在，该系统与LKM1部分重叠，并且它是2型青少年自身免疫性肝炎的一个额外标志物。然而，它无法区分有无HCV感染的患者。
