补体系统参与Ⅱ型麻风反应发病机制的研究现状

Current status of complement system involvement in the pathogenesis of leprosy type Ⅱ

麻风反应是由于机体免疫平衡紊乱引起麻风急性或亚急性活跃的现象。Ⅱ型麻风反应是由B淋巴细胞介导的Ⅲ型超敏反应。该反应通常发生在有效化疗之后,其临床表现主要为结节性红斑(ENL),免疫复合物(IC)体内沉积是ENL反应产生和发展的主要因素,该型反应常反复发作,迁延数年。补体系统参与了体液免疫B淋巴细胞的活化、增殖,并在麻风杆菌(ML)抗原刺激下分化为浆细胞产生特异性抗体lgG、lgM,当抗体再次与抗原结合即形成IC沉积于毛细血管基底膜中,也激活血液中补体的三条级联酶促反应,产生的补体裂解片段过敏毒素C_3a、C_5a和C_3b引起急性组织损伤和较典型的临床症状。

Leprosy reaction is a phenomenon of acute or subacute activity of leprosy caused by disturbance of immune balance. Type II leprosy is a type Dermatology and Venereology,Apr 2019,Vol. 41,No,2 III hypersensitivity mediated by B lymphocyte. This reaction usually occurs after effective chemotherapy, and its clinical manifestation is mainly as erythema nodosum (ENL). Immune complex (IC) deposition in vivo is the main factor for the generation and development of ENL reaction, which often recurs and lasts for several years. Complement system participates in the activation and proliferation of B lymphocyte in humoral immunity, and differentiates into plasma cells stimulated by leprosy bacillus (ML) antigen to produce specific antibodies lgG and lgM. When the antibody binds to antigen again, IC deposits in the capillary basement membrane and also activates three cascade enzymatic reactions of complement in blood. The allergic toxins C3a, C5a and C3b from the fragments of complement lysis cause acute tissue injury and typical clinical symptoms.