Etiology, environmental relationships, epidemiology, and genetics of systemic lupus erythematosus.

The etiology of systemic lupus erythematosus (SLE) and the many lupuslike syndromes continues to challenge investigators. Focus is now on the role of heat-shock proteins, apoptosis, the possible role of diet factors, and in particular, the role of lipids. The role of various infections as either triggering mechanisms or in contributing to morbidity is receiving close attention. In particular, retroviruses are being carefully studied with all the molecular tools available. This area has real promise and carries with it the possibility of anti-infection treatments. Considerably more attention is being paid to the hormonal aspects of SLE and their modulation of the immune system. Environmental associations continue to intrigue investigators and clinicians, and both drugs and other environmental factors provide excellent investigational models. We continue to need good prevalence and incidence studies. Genetically, there is an increasing sophistication in the type of studies, and the ensuing data may well provide real insights into various subsets of SLE.