Xia B, Crusius J B A, Wu J, Zwiers A, van Bodegraven Ad A, Peña A S
Dept. of Gastroenterology, Wuhan University Zhongnan Hospital, Wuhan, People's Republic of China.
Scand J Gastroenterol. 2002 Nov;37(11):1296-300. doi: 10.1080/003655202761020579.
Inflammatory bowel diseases (IBDs) are characterized by chronic intestinal inflammation as a result of an exaggerated T-cell response. CTLA4, a receptor of activated T cells, has an inhibitory function in regulating T-cell activation. Since CTLA4 gene polymorphisms have been associated with several autoimmune diseases, the aim was to study these gene polymorphisms in patients with IBD in two different populations.
The C-318T polymorphism in the promoter region and A+49G polymorphism in exon I of the CTLA4 gene were investigated by a PCR-SSP method. We studied 139 unrelated patients with ulcerative colitis (UC), 163 patients with Crohn disease (CD) and 174 healthy controls of Dutch Caucasian origin as well as 35 patients with UC and 62 healthy controls from the Chinese Han population.
No significant differences in the distribution of allele, genotype and haplotype frequencies were observed between C-318T and A+49G gene polymorphisms and IBD in Dutch Caucasians and UC in the Chinese Han population. Although the haplotypes of the C-318T and A+49G polymorphisms were distributed differently between Dutch Caucasian and Chinese Han populations, there were no differences in the subgroups of patients with CD classified according to age, localization and behaviour in the Vienna classification and in those with UC classified according to age at onset, disease extension and presence of colectomy in the Dutch patients. However, the CTLA4-318 genotype CC was more frequent in patients with CD over 40 years (93%) than in younger patients (74%) (P = 0.045).
C-318T and A+49G CTLA4 gene polymorphisms and their haplotypes are not associated in Dutch Caucasian patients with IBD and in Chinese patients with UC.
炎症性肠病（IBD）的特征是由于T细胞反应过度而导致的慢性肠道炎症。CTLA4是活化T细胞的一种受体，在调节T细胞活化方面具有抑制功能。由于CTLA4基因多态性与多种自身免疫性疾病相关，本研究旨在探讨这两种不同人群中IBD患者的这些基因多态性。
采用PCR-SSP方法研究CTLA4基因启动子区C-318T多态性和外显子I中A+49G多态性。我们研究了139例荷兰白种人来源的非相关溃疡性结肠炎（UC）患者、163例克罗恩病（CD）患者和174例健康对照，以及35例中国汉族UC患者和62例健康对照。
在荷兰白种人中，C-318T和A+49G基因多态性与IBD之间，以及在中国汉族人群中UC与这两种基因多态性之间，等位基因、基因型和单倍型频率分布均无显著差异。尽管荷兰白种人和中国汉族人群中C-318T和A+49G多态性的单倍型分布不同，但根据维也纳分类法按年龄、病变部位和行为分类的CD患者亚组，以及荷兰患者中按发病年龄、疾病范围和结肠切除术情况分类的UC患者亚组之间并无差异。然而，40岁以上的CD患者中CTLA4-318基因型CC的频率（93%）高于年轻患者（74%）（P=0.045）。
在荷兰白种人IBD患者和中国汉族UC患者中，C-318T和A+49G CTLA4基因多态性及其单倍型并无关联。
