Influence of cholecalciferol (vitamin D3) on the course of experimental systemic lupus erythematosus in F1 (NZBxW) mice

The course of systemic lupus erythematosus (SLE), an autoimmune disease, is markedly affected by hormones such as estrogen and prolactin. It is well k nown that heavy exposure to sunlight has deleterious effects on SLE, trigge ring episodes of the disease. Classical explanations for this occurrence su ggest that UV radiation damages DNA, which becomes immunogenic, or induces exposure of the Ro antigen in keratinocytes. In recent years, it has been s hown that vitamin D3 has important effects on the immune system. Thus, we p roposed an alternative hypothesis, suggesting that UV radiation, by promoti ng vitamin D3 synthesis, could be a factor aggravating the course of SLE af ter exposure to sunlight. To test this hypothesis, we injected F1(NZBxW) mi ce, which are prone to developing SLE, with vitamin D3, and we demonstrated a worsening of the histopathological findings in the kidney. (C) 2000 Wile y-liss, Inc.