B-cell activating factor promoter polymorphisms in egyptian patients with systemic lupus erythematosus.

BACKGROUND Systemic lupus erythematosus (SLE) is a heterogonous autoimmune disease involving most immune cells. Studies have revealed a number of cytokine pathways that play important roles in the disease process. Among these is B- cell activating factor (BAFF), which regulates B-cell maturation, survival, and function. OBJECTIVE To study the association between BAFF promoter polymorphism and systemic lupus erythematosus (SLE). METHODS Single nucleotide polymorphisms in the BAFF promoter region; -2841 (T>C), -2701 (T>A), -871 (C>T) were investigated by PCR-RFLP genotyping in fifty Egyptian SLE patients and thirty normal controls. RESULTS The frequency of mutant alleles of both -871C>T and -2701 T>A was higher among SLE patients than controls (p-value <0.001 and 0.000 respectively). There was a highly significant relationship between -871 C>T polymorphism and SLE (P<0.001), with the sensitivity and the specificity of the test being 100 %, and 70%, respectively. Patients expressing the -2701 T>A allele were seven times more prone to SLE than those with the T/T wild genotype (sensitivity of the test = 78%, specificity = 66.7%, odds ratio = 7.09, C.I at 95% = 2.29-22.64). CONCLUSION Polymorphisms in the regulatory region of the BAFF gene do contribute to the susceptibility to SLE in Egyptian patients, which indicates BAFF as a potential therapeutic target.