The effect of vitamin D on disease activity, fatigue and interferon signature gene expression in systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) is multi-system autoimmune disorder, whose pathogenesis involves several cascades that lead to the production of interferon alpha, which then mediates the manifestations of the disease. In SLE, the overexpression of interferon regulated genes, produce a unique interferon signature. This has a positive correlation with disease activity. Vitamin D deficiency is highly prevalent in SLE; the role of vitamin D in the course and prognosis of SLE is unknown. Vitamin D deficiency has been associated with a higher disease activity in SLE. Fatigue is also highly prevalent in SLE; its aetiology is multi-factorial. There is limited evidence on the relationship between vitamin D, fatigue and interferon signature gene expression. Further studies on this will establish whether treatment of vitamin D deficiency in SLE, has any significant effect on the level of fatigue and disease activity, and whether this could be due to the suppression of interferon signature gene expression.