Lindgren S, Braun H B, Michel G, Nemeth A, Nilsson S, Thome-Kromer B, Eriksson S
Dept. of Medicine, University of Lund, Malmö General Hospital, Sweden.
Scand J Gastroenterol. 1997 Feb;32(2):175-8. doi: 10.3109/00365529709000189.
Type-2 autoimmune hepatitis is a subgroup of chronic hepatitis characterized by the presence of liver/kidney microsomal autoantibodies type 1 (LKM-1). A frequent association with chronic hepatitis C suggests that hepatitis virus might trigger autoimmune reactivity. LKM-1-positive chronic hepatitis is not uncommon in southern Europe but is rarely seen in the USA and the UK. The prevalence in Scandinavia is hitherto unknown.
We used an automated prototype LKM-1 immunometry-based assay (IMx) to detect LKM-1 antibodies in sera from 350 Swedish patients with chronic liver diseases (100 with primary biliary cirrhosis, 80 with primary sclerosing cholangitis, 100 with hepatitis C, and 70 patients with various forms of chronic hepatitis, including 36 autoimmune cases), and from 17 children with autoimmune hepatitis. Sera reactive in the IMx assay were subjected to immunofluorescence testing.
No clearly LKM-reactive sera were detected. Serum samples from 29 patients were borderline reactive in the IMx assay but tested negative in the confirmatory immunofluorescence test. Positive tests in the former assay were likely caused by reactivity against microsomal antigens other than LKM-1/cytochrome P450IID6.
LKM-1-positive type-2 autoimmune hepatitis is very rare in Sweden. Furthermore, chronic hepatitis C did not trigger this type of autoimmune reactivity in our patients, probably owing to genetic insusceptibility.
2型自身免疫性肝炎是慢性肝炎的一个亚组，其特征为存在1型肝/肾微粒体自身抗体（LKM-1）。与慢性丙型肝炎的频繁关联提示肝炎病毒可能引发自身免疫反应。LKM-1阳性慢性肝炎在南欧并不少见，但在美国和英国很少见。斯堪的纳维亚半岛的患病率迄今未知。
我们使用基于LKM-1免疫比浊法的自动化原型检测方法（IMx），检测350例瑞典慢性肝病患者（100例原发性胆汁性肝硬化患者、80例原发性硬化性胆管炎患者、100例丙型肝炎患者以及70例各种形式慢性肝炎患者，包括36例自身免疫性病例）和17例自身免疫性肝炎儿童的血清中的LKM-1抗体。对IMx检测中有反应性的血清进行免疫荧光检测。
未检测到明显的LKM反应性血清。29例患者的血清样本在IMx检测中呈临界反应性，但在确证性免疫荧光检测中呈阴性。前一种检测中的阳性结果可能是由于对LKM-1/细胞色素P450IID6以外的微粒体抗原产生反应所致。
LKM-1阳性2型自身免疫性肝炎在瑞典非常罕见。此外，在我们的患者中，慢性丙型肝炎并未引发这种自身免疫反应，可能是由于基因不敏感性。
