Cytotoxic T Lymphocyte Antigen 4 Gene +49 A/G (rs231775) Polymorphism and Susceptibility to Systemic Lupus Erythematosus.

Objective: To assess the probable role of +49AG polymorphism in susceptibility to SLE in an Egyptian population.

Background: Systemic lupus erythematosus (SLE) is a compound inflammatory chronic disease distinguished through the release of autoantibodies. Cytotoxic T lymphocyte associated antigen-4 is a main down controller of T-cell response; its dysregulation could affect SLE pathogenesis by altered T cells activation to self-antigens.

Objective: To evaluate the CTLA-4 +49AG allelic and genotype frequency in a sample of the Egyptian population and correlate them with disease susceptibility and clinical severity.

Methods: Including 100 patients with SLE and 100 healthy controls (age and gender matched), CTLA-4 exon 1 49 A>G Genotyping was done using Real-Time PCR.

Results: No difference was noticed in genotype or allele distributions of the studied polymorphism between both groups. Similar genotypes and allele frequencies were established for the 2 groups after their stratification by the age of disease onset, clinical course, or severity.

Conclusions: CTLA-4 +49AG gene polymorphism is not linked with the liability to develop SLE in the studied Egyptian population. Yet it is significantly related to disease severity.