Epidemiology, genetics, etiology, and environment relationships of systemic lupus erythematosus.

Systemic lupus erythematosus continues to provide a major etiologic challenge. Current investigation is focusing on the possibilities of environmental factors, including infection. How these factors are related to genetic factors, including the major histocompatibility complex and more recently observed defects in apoptosis genes, remains unclear. Ethnic and geographic studies of systemic lupus erythematosus are providing important clues, as are continued clinical observations on the various subsets of disease and the patterns of therapeutic response. Different pathogenic mechanisms are constantly being uncovered and in turn need to be related to the various etiologies.