Background: The associations between the polymorphisms in Cytotoxic T lymphocyte-associated molecule-4 (CTLA-4) gene and Graves' disease (GD) have been extensively investigated in Chinese population. However, the results were inconsistent. The objective of this study is to investigate the associations between the polymorphisms in CTLA-4 gene and the risk of GD by meta-analysis.
Methods: We searched Pubmed database, Medline (Ovid) database, CNKI database and Wanfang database, covering all studies until August 11, 2012. Statistical analysis was performed by using the Revman4.2 software and the Stata10.0 software.
Results: A total of 28 case-control studies concerning the most widely studied three polymorphisms [+49A/G(rs231775), -318C/T(rs5742909) and CT60(rs3087243)] for Chinese population in 21 publications were included. The results suggested that the G allele carriers (GG+GA) might have an increased risk of GD when compared with the AA homozygote carriers for the +49A/G polymorphism (GG+GA vs. AA: OR = 2.57, 95%CI = 1.87-3.52). However, as to the -318C/T polymorphism and CT60 polymorphism, the results indicated that the variant allele carriers might have decreased risks of GD when compared with the homozygote carriers (-318C/T: TT+TC vs. CC: OR = 0.78, 95%CI = 0.62-0.97; CT60: AA+AG vs. GG: OR = 0.64, 95%CI = 0.52-0.78).
Conclusions: The current meta-analysis indicated that the polymorphisms in the CLTA-4 gene might be risk factors for GD in the Chinese population. In future, more large-scale case-control studies are needed to validate these results.