中国人自身免疫性肝病相关性 CTLA-4基因多态性研究

目的　探讨细胞毒性 T细胞相关抗原 - 4 (cytotoxic T lymphocyte- associated antigen- 4 ,CTL A- 4 )基因启动子 - 318和第 1外显子区第 4 9位基因多态性与中国人自身免疫性肝炎 (autoimmunehepatitis,AIH)、原发性胆汁性肝硬化 (primary biliary cirrhosis,PBC)发病的相关性。方法　应用限制性片段长度多态性方法分析 6 2例 AIH和 77例 PBC患者外周血单核细胞基因组 DNA CTL A- 4启动子 -318T/ C、第 1外显子区第 4 9位基因 A/ G多态性 ,并与 16 0名正常对照比较。结果　 AIH组 CTL A- 4启动子 - 318位 T/ C基因型分布与对照组比较差异无显著性 ,但 C等位基因频率明显高于正常对照组 (P=0 .0 2 ,OR=2 .4 3)。 PBC患者 CTL A- 4第 1外显子区第 4 9等位基因分布与正常对照组比较差异非常显著(P=0 .0 0 6 ) ,PBC患者 G等位基因频率明显高于正常组 (P=0 .0 0 4 6 ,OR=1.8)。联合分析 CTL A- 4启动子与第 1外显子的基因多态性分布 ,虽然 AIH组和 PBC组 GG- CC型携带率均比正常人高 (AIH组 :32 .3% ,PBC组 :37.7% ,对照组 :2 2 .5 % ) ,但是统计学分析结果均显示两组患者与正常人差异无显著性。结论　 CTL A- 4启动子 - 318和第 1外显子区第 4 9位基因多态性可能与中国人 AIH、PBC易感性相关。

Study on the relationship of CTLA-4 -318, +49 polymorphisms with autoimmune hepatitis and primary biliary cirrhosis in a Chinese population

Objective To investigate the association between Chinese patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and the polymorphisms of cytotoxic T lymphocyte-associated antigen-4 ( CTLA-4) gene promoter (-318) and exon 1 ( 49). Methods The CTLA-4 promoter (-318 T/C) and exon 1 ( 49A/G) polymorphisms were genotyped via restriction fragment length polymorphism methods in 62 Chinese AIH patients, 77 Chinese PBC patients and 160 healthy controls. Results There was no difference in the distribution of CTLA-4 promoter -318 T/C polymorphisms between AIH patients and controls, but the C allele frequency was significantly increased in patients with AIH, compared to controls (P=0.02, OR=2.43). The distribution of CTLA-4 gene exon 1 49 A/G genotypes exhibited significant difference between PBC patients and controls (P=0.006), and the frequency of G allele showed a significant increase in PBC group as compared with controls (P=0 0046, OR=1.8). Although the genotype distribution of the CTLA-4 exon 1-promoter gene displayed no significant difference between AIH and PBC patients and controls, the occurrence of GG-CC was increased in the patients of the two groups (AIH: 32.3%, PBC: 37.7%; control: 22.5%). Conclusion The above findings suggest that the polymorphisms of CTLA-4 gene probably confer susceptibility to AIH and PBC in the Chinese population.