Sunlight-induced pathogenesis in systemic lupus erythematosus

Abstract

A broad range of immunologic abnormalities have been observed in SLE patients. However, we do not know the extent to which exposure to UV radiation may contribute to the immunologic problems encountered by patients. UV radiation has been found to alter in vivo and in vitro immune functions. Several in vitro effects have been documented, including the recent observations that UV radiation enhances the release and/or synthesis of epidermal thymocyte-activating factor (ETAF) in human and mouse keratinocytes. ETAF appears to be biochemically similar to interleukin 1, an important lymphocyte-activating factor. How UV-induced alterations of the immune system may lead to new skin lesions or systemic progression of the disease is an entirely open question. A continued growth in our understanding of the pathogenesis of SLE will surely occur as investigators begin exploring photoimmunologic responses in SLE.