association of single nucleotide polymorphism of interleukin-21 gene and serum interleukin-21 levels with systemic lupus erythematosus

ABSTRACT

Background: Systemic lupus erythematosus [SLE] is a common autoimmune disorder which commonly results from the combined effects of a large number of genes. Variations in the DNA sequence in the Interleukin-21 [IL-21] gene may lead to altered IL-21 production and/or activity which can affect an individual's susceptibility to SLE. IL-21 is a novel class I cytokine produced by activated CD4+ T cells, natural killer T cells and T helper [Th] cells. There is increasing evidence that IL-21 contributes to the pathogenesis of SLE due to its biological activity