CTLA-4 Gene Polymorphism and the Risk of Systemic Lupus Erythematosus in the Chinese Population

Ahmad Taha Khalaf,Tie-Chi Lei,Ji-Quan Song,Ting-Ting Gao,Xiang-Ping Yu

doi:10.1155/2011/167395

Abstract

Several variants of CTLA-4 have been reported to be associated with susceptibility systemic lupus erythematosus (SLE); however, findings have been inconsistent across different populations. Using a case-control study design, we have investigated the role of CTLA-4 polymorphism at positions −1661 and −1722 on SLE susceptibility in our Chinese SLE population in central China's Hubei province. Samples were collected from 148 SLE patients and 170 healthy controls. Polymerase chain reaction restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotypes of the two sites. Statistically significant difference was observed in genotypes for −1722, but not for −1661. The frequency of the T allele on the −1722 SNP was significantly increased in SLE patients: 57.8% versus 40.6% in controls (P < 0.001, OR = 2.002). While the detected C allele frequency in the controls was significantly elevated in comparison to that in the SLE patients (59.4% versus 42.2%). On the contrary, no association was found between SLE and CTLA-4 polymorphism at position −1661.

Highlights

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease and is considered to be caused by complex interactions between genetic risk, environmental, and hormonal factors that result in an immune dysregulation, and autoantibody production ensued [1,2,3]
The genotypic frequencies for the two sites tested were not found to be deviated from those predicted from HardyWeinberg equilibrium in both SLE patients and controls
Liu et al did not observe an association of CTLA-4 polymorphism with SLE in Taiwanese, but suggested that it is possible that this polymorphism could affect some specific clinical features [20]

Summary

Introduction

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease and is considered to be caused by complex interactions between genetic risk, environmental, and hormonal factors that result in an immune dysregulation, and autoantibody production ensued [1,2,3]. Only few of them have been studied for association with SLE susceptibility, of which, two are located within the promoter region: a T/C change at position −1722 and an A/G transition at position −1661 [11,12,13]. The former could alter transcription factor binding sites whereas the latter may alter the potential response element for myocyte enhancer factor 2 (MEF2) [14]. Using a case-control study design, we have investigated the role of CTLA-4 polymorphism at positions −1661 and −1722 on SLE susceptibility in our Chinese SLE population in central China’s Hubei Province

Patients and Methods

Results and Discussion

Conclusions