The association of 1661AG polymorphism for CTLA-4 gene in patients with systemic lupus erythematosus

Cytotoxic lymphocyte antigen-4 (CTLA-4) plays an important role in regulating T cell activation. CTLA-4 gene polymorphism is related to genetic susceptibility to various autoimmune diseases, including systemic lupus erythematosus (SLE). This study aimed to evaluate the role of CTLA-4 polymorphism at positions-1661AG in patients with SLE. This study was performed on 180 SLE patients referred to 5th Azar educational hospital (Gorgan, Iran, during 2010-2011) and 304 ethnically-and age-matched healthy controls. Polymerase chain reaction restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotype and allele frequencies of this polymorphism. No statistically significant difference was observed between the studied genotypic and allelic frequencies between the SLE patients and healthy controls. Moreover, no significant correlation was found between the different risk factors (e.g., age, ethnicity, history of the disease and the parent's relationship) and the different genotypes. Results suggest that the -1661AG polymorphism in the promoter region of the CTLA-4 gene has no role in the genetic susceptibility to SLE.