[Autoimmune diseases and seasonal variations]

It has been reported that the exacerbation or development of autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis may have seasonality, although the seasonal characteristic depends on each disease. For example, the sunlight (ultraviolet) and infectious pathogens are involved in important environmental factors contributing the seasonality of the diseases. Furthermore, recent advances include the association between vitamin D and autoimmune diseases, and the different pathogenesis among the same clinical category according to the autoantibodies.