Association between CTLA-4 gene polymorphism and the risk of systemic lupus erythematosus: Brief report

Background: Cytotoxic lymphocyte antigen-4 (CTLA-4) plays an important role in regulating T cell activation. CTLA-4 gene polymorphisms are related with genetic susceptibility to various autoimmune diseases, including systemic lupus erythematosus (SLE). We analyzed the role of CTLA-4 polymorphisms at positions -318CT in patients who suffer from SLE. Methods: This study was performed on 180 SLE patients referred to 5th Azar University Hospital in Gorgan, Iran. Three hundred and four ethnically-and age-matched healthy controls with no history of autoimmune diseases entered the study between 5th May 2008 and 23rd October 2009. DNA was extracted from blood samples according to the standard procedure. Polymerase chain reaction- restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotype and allele frequencies of this polymorphism. PCR was carried out using the following primers: forward 5′- AAATGAATTGGACTGGATGGT-3′ and reverse 5′-TTACGAGAAAGGAAGCCGT G-3′. The frequency of alleles and genotypes were assessed using direct counting. Chisquare test and Fisher’s exact test were used to compare the association between the alleles and genotype frequencies and SLE. P<0.05 were considered statistically significant. Results: The CC genotype was observed in 94.5% of the SLE patients and 82.4% of the controls; the difference was statistically significant (P=0.0001, OR=3.51, CI95%=1.77- 7.53). The CT genotype, on the other hand, was more frequently observed in the control group (17.1% vs. 5.5%, P=0.0001, OR=0.28). T allele was significantly more common in the controls compared to SLE patients (P=0.0001, OR=0.26, CI95%=0.13-0.53). Conclusion: Our results suggest that the -318C/T polymorphism of CTLA-4 gene might play a significant role in the genetic susceptibility to SLE. Therefore, further studies on populations, especially from other Middle East countries, are needed to confirm our results. © 2015, Tehran University of Medical Sciences. All Rights Reserved

No evidence of association between CTLA-4 polymorphisms and systemic lupus erythematosus in Iranian patients

Aim: Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is an important negative regulator of T-cell responses. CTLA-4 polymorphisms have been confirmed to be associated with several autoimmune diseases such as systemic lupus erythematosus (SLE). We analyzed the role of CTLA-4 polymorphism at positions -1661 and -1722 in Iranian patients suffering from SLE. Methods: One hundred and eighty SLE patients and 304 ethnically and age-matched healthy controls were studied. Polymerase chain reaction restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotype and allele frequencies of these polymorphisms. Results: There was no significant association between the studied genotypic and allelic frequencies between SLE patients and the controls. Although the TC genotype in 1722TC polymorphism was more common among the control group, the correlation was not statistically significant. Conclusion: Our results suggest that the -1661AG and -1722TC polymorphisms in the promoter region of the CTLA-4 gene does not play any role in genetic susceptibility to SLE. However, further studies on larger sample sizes are needed to approve our results. © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd