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目的 炎症性肠病 (IBD)的发病机制与T细胞免疫应答过度有关。细胞毒T淋巴细胞相关抗原 4(CTLA 4)主要在已激活的T细胞上表达 ,通过与CD2 8竞争与B7结合 ,抑制T细胞激活 ,维持免疫系统内环境稳定。CTLA 4基因多态性与一些自身免疫性疾病相关 ,但未见其与IBD的研究。本研究旨在了解IBD的遗传易感性。方法 对 68例无血缘关系的湖北汉族IBD患者 (54例溃疡性结肠炎 ,14例克罗恩病 )以及 14 0例正常对照者 ,采用序列特异性引物PCR方法检测CTLA 4外显子 4的 3′非转录区包含AT重复序列的特异性等位基因。扩增产物用 12 %非变性聚丙烯酰胺凝胶电泳 ,硝酸银染色 ,部分样品经测序以确定片段长度。结果 共发现CTLA 4基因有 18种等位基因 ,与正常对照组比较 ,12 2bp等位基因在溃疡性结肠炎患者中显著增高 (7 4%vs 0 3 % ,P =0 0 0 0 2 /Pc =Sig ,OR =2 2 3 2 ,95%CI :2 76～ 180 80 )。结论 CTLA 4基因微卫星多态性与溃疡性结肠炎显著相关
The purpose of the pathogenesis of inflammatory bowel disease (IBD) and T-cell immune response over. Cytotoxic T lymphocyte-associated antigen 4 (CTLA 4) is mainly expressed on activated T cells and binds to B7 by competing with CD28 to inhibit T cell activation and maintain the stable internal environment of the immune system. CTLA4 gene polymorphism is associated with some autoimmune diseases, but no studies have been done with IBD. This study aims to understand the genetic predisposition of IBD. Methods Sixty-eight unrelated Han Chinese IBD patients (54 ulcerative colitis, 14 Crohn’s disease) and 140 normal controls were enrolled in this study. Sequence-specific PCR was used to detect the expression of CTLA 4 exon 4 The 3 ’non-transcribed region contains the specific allele of the AT repeat. The amplified product was electrophoresed on a 12% non-denaturing polyacrylamide gel, stained with silver nitrate, and some of the samples were sequenced to determine the fragment length. RESULTS: A total of 18 alleles of CTLA 4 gene were found in the patients with ulcerative colitis (74% vs 0 3%, P = 0.00002 / Pc = Sig, OR = 2 2 3 2, 95% CI: 2 76-180 80). Conclusion The microsatellite polymorphism of CTLA 4 gene is significantly associated with ulcerative colitis