[The research on associating the single nucleotide polymorphism of CTLA-4 gene promoter region with idiopathic dilated cardiomyopathy].

ABSTRACT

OBJECTIVE: To investigate the expression of cytotoxic T lymphocyte associated antigen-4 (CTLA-4) in patients with idiopathic dilated cardiomyopathy (IDC) and to explore genetic susceptibility to IDC caused possibly by single nucleotide polymorphism (SNP) of CTLA-4 gene promoter. METHODS: PCR-restriction fragment length polymorphism techniques were used to analyze the SNPs of CTLA-4 gene at position -1772, -1661 and -318 in the promoter region. Serum sCTLA-4, IFN-gamma and IL-4 were tested by ELISA. RESULTS: sCTLA-4 levels of IDC patients were associated with the haplotype and genotype. Patients with -1772 TC genotype or -1772 TC -1661 AA, -1772 TC -1661 AG haplotypes had higher sCTLA-4 levels than patients with other haplotypes did. The frequency of -1772 TC genotype was significantly high in patients with low ejection factor(EF) values. Whereas the frequencies of -1661 G allele and -1661 GG genotype were lower in IDC patients. Levels of IL-4 were increased in IDC group. CONCLUSION: Patients with IDC have an aberrant expression of the CTLA-4 products, and the -1772 C/T and -1661 A/G polymorphisms. The two SNPs may function as genetic markers for disease susceptibility.