炎症性肠病患者抑制性杀伤细胞免疫球蛋白样受体基因多态性分析

Analysis of gene polymorphisms of inhibitory killer cell immunoglobulin-like receptor in patients with inflammatory bowel disease

目的分析炎症性肠病（inflammatory bowel disease，IBD）患者抑制性杀伤细胞免疫球蛋白样受体（killer cell immunoglobulin—likereceptor，iKIR）基因多态性，探讨iKIR基因多态性与IBD的关联性。方法收集100例溃疡性结肠炎（UC）、52例克罗恩病（CD）患者和106名种族匹配的健康对照者外周血DNA标本，采用序列特异性引物聚合酶链反应（PCR—SSP）方法，分析上述对象iKIR基因位点的多态性，计算iKIR基因表型频率和基因频率，比较IBD患者与健康对照者间的差异。结果iKIR基因（包括KIR2DL1、KIR2DL2、KIR2DL3、KIR2DL4、KIR2DL5、KIR3DL1、KIR3DL2、KIR3DL3）在IBD患者和健康对照组均有不同程度的表达。UC患者KIR2DL1和KIR2DL3表现型频率比健康对照组显著降低（P=0．001），而KIR2DL2、KIR2DL4、KIR2DL5、KIR3DL1、KIR3DL2和KIR3DL3表现型频率与健康对照组比较差异无统计学意义（P〉0．05）。CD患者KIR2DL1表现型频率比健康对照组显著降低（P=0．007），而其余iKIR基因表现型频率与健康对照组比较差异无统计学意义（P〉0．05）。结论KIR2DL1和KIR2DL3表现型频率在UC患者中显著下降，提示其与UC的易感性有密切关系；而KIR2DL1基因可能与CD易感性密切相关。

Objective To investigate the gene polymorphism of inhibitory killer cell immunoglobulinlike receptor （iKIR） in patients with inflammatory bowel disease （IBD） and whether the iKIR gene polymorphisms were associated with IBD. Methods Peripheral blood DNA samples were isolated from 100 patients with ulcerative colitis （UC）, 52 patients with Crohn＇s disease （CD） and 106 randomly ethnically matched healthy controls. The iKIR gene polymorphisms were analyzed by sequence specific primer polymerase chain reproduction （PCR-SSP）. Phenotypic frequency and gene frequency of iKIR gene were calculated, and differences were compared between IBD patients and healthy controls. Results iKIR genes （ including KIR2DL1, KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5, KIR3DL1, KIR3DL2, KIR3DL3） were found to be present in all subjects at different levels. Interestingly, phenotypic frequencies of KIR2DL1 and KIR2DL3 were significantly lower in UC patients than those in healthy controls （P = 0. 001）, while phenotypic frequencies of KIR2DL2, KIR2DL4, KIR2DL5, KIR3DL1, KIR3DL2 and KIR3DL3 were no difference between UC patients and healthy controls （P 〉0.05）. The phenotype frequency of KIR2DL1 was significantly decreased in CD patients compared with healthy controls （P = 0.007）, while phenotypic frequencies of other iKIR were observed to be no significant change between CD patients and healthy controls （P 〉0. 05 ）. Conclusions The KIR2DL1 and KIR2DL3 gene phenotype frequencies are decreased in UC patients, which suggests that these gene polymorphisms are associated with the susceptibility of UC, and the polymorphism of KIR2DL1 gene is involved in the susceptibility of CD.