Association of CTLA-4 exon 1(+49 A/G) polymorphism and susceptibility to SLE in Egyptian children and adolescents

BackgroundRecently, Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) gene has emerged as an attractive candidate gene implicated in susceptibility to autoimmune disease such as Juvenile-onset SLE (JSLE).ObjectiveTo investigate <i>CTLA-4</i> exon 1 + 49A/G (rs231775) <i>SNP</i> as a genetic marker for susceptibility to JSLE and lupus nephritis in Egyptian children and adolescents.MethodsThis prospective case-control study included 260 patients diagnosed with Juvenile-onset SLE, and 260 healthy controls. We genotyped all participants for CTLA-4 (A/G) (rs231775) <i>SNP</i> located in exon 1 at position 49 by polymerase chain reaction.ResultsThe <i>CTLA-4</i> exon 1 + 49<i>G/G</i> gene variant and <i>G</i> allele were significantly more represented in JSLE patients than healthy controls (27% vs 8%; ORs = 4.2; [95% CI: 2.4 - 7.3]; for the <i>G/G</i> genotype) and (47.5% vs 35%; ORs: 1.7; [95% CIs: 1.3 - 2.2]<i>;</i> for <i>G</i> allele); <i>P</i> < .01. The <i>CTLA-4 G/G</i> genotype and <i>G</i> allele were identified as possible risk factors for development of lupus nephritis (for <i>G/G</i> genotype; ORs: 5.09; [95% CIs: 1.7 - 13.9]; <i>P</i> = .0001, and for <i>G-</i>allele; ORs: 2.4; [95% CIs: 1.5 - 3.78]; <i>P</i> = .004).ConclusionThe <i>CTLA-4</i> exon 1 + 49<i>A/G</i> polymorphism may confer susceptibility to Juvenile-onset SLE. Moreover, <i>CTLA-4 G/G</i> genotype and <i>G</i> allele at exon 1 + 49 may constitute independent risk factors for development of lupus nephritis in Egyptian children and adolescents.