The CTLA4 + 49A/G and CT60 polymorphisms and chronic inflammatory arthropathies in Northern Ireland

Rheumatoid and juvenile idiopathic arthritis (RA, JIA) are chronic inflammatory arthropathies with an autoimmune background. The cytotoxic T-lymphocyte antigen-4 (CTLA-4) protein plays a key role in the down-regulation of T cell activation.We analyzed the CTLA4 +49A/G and CT60 polymorphisms in cohorts of Northern Irish RA and JIA patients and healthy control subjects using restriction fragment length polymorphism methods.The + 49 A allele was increased in RA (61.2%; P = 0.02; OR = 1.28; 95% C.I. = 1.04–1.58) and JIA (61.8%; P = 0.14) patients compared to the control population (55.3%). No significant association was observed for the CT60 polymorphism. Haplotype analysis revealed a significantly different distribution of + 49 A/G-CT60 haplotypes in RA and JIA patients compared to controls (P value < 0.00001 and 0.030 for comparison of RA and JIA patients with controls, respectively).Our results suggest that the CTLA-4 gene is involved in predisposition to inflammatory arthropathies in the Northern Irish population.