近年来,重叠胶原病或称重叠综合征(Overlap Syndrome)颇受重视。如系统性红斑狼疮(SLE)与类风湿性关节炎(RA),硬皮病(PSS)与SLE,PSS与多发性肌炎(PM)重叠很早已有报道。但对它集中注意是由Sharp提倡混合结缔组织病(Mixed connective tissue disease,简称MCTD)的概念之后才开始的。一般认为MCTD与其他重叠综合征有根本上的差别,应作为一种独立疾病来加以研究。实际上MCTD按大藤的分类属于Ⅱ型重叠胶原病,是几种胶原病表现互相融合而构成的新的独立病种,是研究胶原病具有代表性的疾病。本文重点介绍MCTD的临床表现及其免疫学特点。发现及发生率 Sharp发现有些病例具有硬皮病、皮肌炎、多发性肌炎和红斑性狼疮等病的混合表 In recent years, overlapping collagen disease or overlap syndrome (Overlap Syndrome) is valued. Such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), scleroderma (PSS) and SLE, PSS and polymyositis (PM) overlap has long been reported. But focusing on it started with Sharp’s notion of mixed connective tissue disease (MCTD). It is generally believed that there is a fundamental difference between MCTD and other overlapping syndromes and should be studied as an independent disease. In fact MCTD according to the big rattan belongs to the type II collagen disease, is the emergence of several collagen disease merged with each other to form a new independent disease, collagen disease is a representative study of the disease. This article focuses on the clinical manifestations of MCTD and its immunological characteristics. Discovery and Incidence Sharp found that some cases had mixed tables of diseases such as scleroderma, dermatomyositis, polymyositis and lupus erythematosus