Association of cytotoxic T lymphocyte associated antigena4 gene (rs60872763) polymorphism with Crohn's disease and high levels of serum sCTLAa4 in Crohn's disease

Background and Aim: Our aim was to evaluate cytotoxic T lymphocyte associated antigen-4 (CTLA-4) gene polymorphisms in Crohn's disease (CD) and explore soluble CTLA-4 (sCTLA-4) levels in serum of CD patients in central China. Methods: A total of 126 Chinese CD patients and 300 healthy controls were enrolled in this study. CTLA-4 (AT)n repeat polymorphism was genotyped by a semiautomatic fluorescently labeled polymerase chain reaction (PCR) method, and CTLA-4 -1661A/G and -1722T/C polymorphisms were genotyped by DNA sequencing. Serum sCTLA-4 and C-reactive protein (CRP) levels were determined by enzyme linked immunosorbent assay (ELISA) and immunonephelometry, respectively. Results: The frequency of 84bp allele of CTLA-4 (AT)n repeats was lower in CD patients than in the healthy controls (22.2% vs 33.2%, P=0.001, odds ratio=0.58, 95% confidence interval: 0.41-0.81). The 84bp allele carriers of (AT)n repeats were associated with non-stricturing and non-penetrating disease behavior in CD patients (P=0.007). Serum sCTLA-4 levels were more elevated in CD patients than in the healthy controls (P