Genes in the HLA class III region and their products in patients with rheumatoid arthritis and Sjogren's syndrome.

对干燥综合征（SS）和类风湿关节炎（RA）患者的DNA、补体第四组分（C4）和因子B （Bf）进行了分子生物学分析。我们得到的结果是：1。在许多种族群体中，RA与HLA- DR4和DRw53之间存在良好的相关性。在本研究中，我们观察到RA患者中C4B5的频率显著增加，尤其是在男性患者中。由于在日本有报道C4B5、DR4和DRw53基因之间存在强烈的连锁不平衡，并且其他民族的RA患者与C4B5没有关联，因此C4BS对RA的发展不具有直接作用。2. 在无其他自身免疫性疾病（原发性SS）的SS患者中经常观察到C4A空值（c4aqos）。采用CDNA探针对C4、CyP21和4种限制性内切酶的5'端进行Southern blot分析，研究了c4aqs患者和对照组的基因组DNA。结果表明，大多数日本人的c4aqs病例不是由于C4A基因的主要缺失。

Molecular biological analysis of DNA and the allotypes of the fourth component of complement (C4) and Factor B (Bf) were studied in patients with Sjogren's syndrome (SS) and rheumatoid arthritis (RA).The result we obtained were: 1. There is a well documented awqssociation between RA and HLA- DR4 and DRw53 in many racial groups. In this study, we observed a significantly increased frequency of C4B5 in RA patients, especially in male patients. Since a strong linkage disequilibrium among genes of C4B5, DR4 and DRw53 is reported in Japanese, and since RA patients in other ethnics are not associated with C4B5, the C4BS was supposed not to have a direct role for the development of RA. 2. C4A null (C4AQO) was frequently observed in SS patients without other autoimmune disease (primary SS). By Southern blot analysis using CDNA probes for the 5' end of C4 and CyP21 and four restriction enzymes, genomic DNA from patients and controls with or without C4AQO were studied. The results suggest that most examples of C4AQO in the Japanese are not due to a major deletion of the C4A gene.