IMMUNOLOGIC STUDIES IN PRIMARY BILIARY CIRRHOSIS

异常免疫机制正在研究中， 原发性胆汁性肝硬化（PBC）。 T细胞介导的帮助， 美洲商陆丝裂原诱导免疫球蛋白抑制 已经使用放射免疫测定法研究了B细胞的合成， 测量由含有以下物质的培养物合成的IgG和IgM 不同淋巴细胞亚群的适当混合物， 体外 T细胞的增殖能力，当培养与 自体或同种异体照射的B细胞（混合的 淋巴细胞反应）进行了评估。 这些研究结果 包括在PBC中展示（i）T的能力减弱 细胞体外抑制免疫球蛋白合成，和（ii）a 自体非异体混合缺陷 淋巴细胞反应 这些发现表明，在PBC中， 自身反应性T细胞与 自体非T细胞上的细胞和表面抗原 抑制性T细胞的活化减少， 容易产生免疫反应过度 的 伊加缺乏症和PBC的共存已被记录。 它 伊加缺乏可能有助于发展 但PBC的发病并不需要伊加- 依赖机制。 PBC患者的血清已被 显示包含一个因素，可能是一个异常的 免疫反应性IgM，其阻断C3 b调理素化的 红细胞和单核细胞。 这一发现提供了一个潜在的 C3 b受体特异性清除缺陷的解释 固定PBC中的巨噬细胞。 PBC患者已被证明 自然杀伤细胞活性降低， 溶细胞效应细胞的缺陷。 体液免疫缺陷 由于B细胞亚群的活化， 疾病 例如，在PBC中，有证据表明， 存在扩增的B细胞克隆， 不同抗原特异性的线粒体抗体 与正常B细胞合成的不同。 疾病特异性 免疫缺陷在PBC中尚未被定义。

Abnormal immune mechanisms are being studied in patients with primary biliary cirrhosis (PBC). T cell-mediated help and suppression of pokeweed mitogen-induced immunoglobulin synthesis by B cells have been studied using radioimmunoassays to measure IgG and IgM synthesized by cultures containing appropriate mixtures of different lymphocyte subpopulations in vitro. The ability of T cells to proliferate when cultured with either autologous or allogeneic irradiated B cells (mixed lymphocyte reactions) has been assessed. Results of these studies include the demonstration in PBC of (i) a diminished capacity of T cells to inhibit immunoglobulin synthesis in vitro and (ii) a deficiency of the autologous but not the allogeneic mixed lymphocyte reaction. These findings suggest that in PBC there is a fundamental defect in the interaction between autoreactive T cells and surface antigens on autologous non-T cells which leads to diminished activation of suppressor T cells and hence predisposes to a state of immune hyperresponsiveness. The coexistence of IgA deficiency and PBC has been documented. It is possible that IgA deficiency may contribute to the development of PBC, but the pathogenesis of PBC does not require IgA- dependent mechanisms. Sera from patients with PBC have been shown to contain a factor, probably an abnormally immunoreactive IgM, which blocks the binding of C3b-opsonized erythrocytes by monocytes. This finding affords a potential explanation for the C3b-receptor specific clearance defect by fixed macrophages in PBC. Patients with PBC have been shown to have diminished natural killer cell activity due to a functional defect of cytolytic effector cells. Defects of humoral immunity due to activation of subpopulations of B cells occur in this disease. For example, in PBC there is evidence compatible with the existence of an expanded clone of B cells that synthesize mitochondrial antibodies with different antigenic specificities from those synthesized by normal B cells. A disease-specific immunologic defect has yet to be defined in PBC.