RFLP analysis of HLA and T cell receptor genes in sarcoidosis

结节病是一种病因不明的全身性肉芽肿性疾病。结节病的发病机制尚不清楚，但一些检查表明患者存在免疫紊乱或存在遗传机制。我们先前报告了在结节病中与人类白细胞抗原DRU52的显著关联。在本研究中，我们对结节病患者的人类白细胞抗原基因和T细胞受体基因进行了RFLP分析。从患者和健康对照组的外周血淋巴细胞中提取DNA。所用探针为HL-DRbeta、DQpha(和DQbeta)及T细胞受体α和Beda链，RFLP分析可以检测到常规血清学分型无法区分的HLA-DRbedA基因的多态性。DRbedA基因的5个限制性片段仅见于DRU52阳性个体，在患者中出现的频率高于对照组，但没有任何限制性片段是结节病所特有的。完全相同的个体的片段模式彼此相似，根据片段的存在可以将患者分为两组。DQα和DQβ基因的RFLP分析也比血清学方法具有更多的微小多态性，但没有观察到DQ基因之间的明显关联。这些结果表明DR抗原在结节病的发病机制中起主要作用。对于T细胞受体基因，在结节病患者中未观察到V区的特异性重排。T细胞受体基因的限制性片段在患者和对照组之间的频率无显著差异。这些结果表明，可能存在异种抗原导致结节病。

Sarcoidosis is a systemic granulomatous disease with unknown etiology. The pathogenesis of sarcoidosis still remains unclear, but some examinations indicate an immunologic disorder of the patients or the existence of genetic mechanisms. We previously reported a significant association with HLA-DRw52 atitigeri in sarcoidosis. In this study, we performed RFLP analysis of HLA genes arid T cell receptor genes in patients with sarcoidosis. DNA was extracted from peripheral blood lymphocytes of the patients and healthy control subjects. The probes used were cDNA of HL-DRbeta, DQalpha(and DQbeta and T cell receptor alpha and beda chain.The RFLP analysis could detect polymorphism of the HLA-DRbeda gene that was not distinguishable by conventional serological typing. Five restriction fragments of DRbeda gene were only seen in DRw52-positive individuals, and snowed greater frequencies in the patients than in control subjects, although no restriction fragments were specific for sarcoidosis. The patterns of the fragments in exact individual resembled one another, and patients could be divided into two groups according to the presence of the fragments. The RFLP analysis of DQalpha and DQbeta genes also could more minute polymorphism than serological metliods, but a distinct association of DQ genes was not observed. These results indicate that DR antigens play a major role in the pathogenesis of sarcoidosis.As for T cell receptor genes, no specific rearrangement of V region were observed in sarcoidosis patients. Restriction fragments of T cell receptor genes snowed no significant difference in the frequencies between the patients and control subjects. These results suggest that there may be heterogenous antigens that cause sarcoidosis.