Association of CTLA4 gene A-G polymorphism with rheumatoid arthritis in Chinese.

The aim of this study was to investigate the allelic association of a single nucleotide polymorphism in exon 1 of the cytotoxic T-lymphocyte antigen-4 (CTLA4) gene with rheumatoid arthritis (RA) in Chinese people. One hundred and eighty-six unrelated adults with RA and 203 randomly selected normal adults were studied. All were ethnic Chinese living in Taiwan. The CTLA4 A-G polymorphism was genotyped with a polymerase chain reaction (PCR) and digestion with the restriction enzyme BstEII. The genotype and allele frequencies of CTLA4 in patients with rheumatoid arthritis differed significantly from those of adult controls (P=0.022 and P=0.037, respectively). Genotype CTLA4 49 G/G and allele G were associated with an increased risk of RA (RR=1.72, 95% CI=1.15-2.57, P=0.008; RR=1.39, 95% CI=1.02-1.89, P=0.037, respectively), whereas genotype A/G and allele A were associated with protection against RA (RR=0.58, 95% CI=0.39-0.87, P=0.008 and RR=0.72, 95% CI=0.53-0.98, P=0.037, respectively). We concluded that, the CTLA4 49 A-G polymorphism is associated with RA in Chinese patients from Taiwan.