IgG class antibody to hepatic endothelial cell in sera of patients with autoimmune hepatitis and its pathophysiological significance

在自身免疫性肝炎（AIH）患者血清中发现了一种抗大鼠肝窦内皮细胞（HSECs）的抗体。从大鼠肝脏中分离HSECs，培养18 h，用戊二醛固定。细胞经1：250 AIH患者的血清稀释,慢性B型肝炎或C,或正常的健康受试者,免疫球蛋白的绑定是评估peroxdaseconjugated蛋白质在14 15 AIH患者,免疫球蛋白绑定到细胞的数量超过了正常的意思是+ 3 sd健康受试者和慢性B型肝炎患者C.Treatment AIH患者的血清二硫苏糖醇碘乙酰胺并没有减少免疫球蛋白HSECs。此外，通过消化AIH患者IgG制备的F(ab')2保留了与HSECs结合的活性。这些结果表明抗原决定因子是hscs表面的肝素样结构。在患者接受皮质类固醇治疗后，与细胞结合的IgG的数量明显减少。在AIH患者IgG存在的情况下培养HSECs，减少了附着在培养皿上的细胞数量，表明抗体损伤了培养的HSECs。从这些结果来看，抗hsc的抗体可能参与了AIH的发病机制。

An antibody against rat hepatic sinusoidal endothelial cells (HSECs) was identified in the serum of patients with autoimmune hepatitis (AIH). HSECs were isolated from rat liver, cultured for 18 h and fixed with glutaraldehyde. After incubation of the cells with 1 : 250 dilutions of serum from patients with AIH, chronic hepatitis type B or C, or normal healthy subjects, the amount of IgG bound was evaluated with peroxdaseconjugated protein A.In 14 of 15 patients with AIH, the amount of IgG bound to the cells exceeded the mean plus 3SD of normal healthy subjects and patients with chronic hepatitis type B and C.Treatment of the sera from AIH patients with dithiothreitol and iodoacetamide did not reduce the amount of IgG bound to HSECs. Furthermore, F(ab')2, prepared by peptic digestion of IgG from AIH patients, retained the activity to bind to HSECs. These findings indicate that the antigen determinant was a heparin-like structure on the surface of HSECs. The amount of IgG bound to the cells was significantly reduced after the patients were treated with corticosteroids. Culture of HSECs in the presence of IgG from AIH patients reduced the number of cells attached to the dish, suggesting that the antibody injured the cultured HSECs. From these results, the antibody against HSECs may contribute to the pathogenesis of AIH.