ABSTRACT
Autoimmune diseases are immunogenetically determined disorders of immune regulation that have complex and multifactorial etiologies. Sex is one factor that greatly influences the development and severity of autoimmune disease. Although the marked female predominance of systemic lupus erythematosus (SLE) and other autoimmune diseases has been known for decades, it is only recently that we can explain this clinical fact scientifically. We now know that sex steroid hormones greatly influence autoimmunity, with androgens suppressing and estrogens accelerating disease. These facts were first established in the NZB/NZW F1 (B/W) model for SLE (1-4), but they are seen in other autoimmune models as well (5,6). Moreover, the ability of sex steroid hormones to modulate murine lupus is basically a physiologic effect of these hormones acting on an aberrant system of immunoregulation. Even in normal people and animals, sex differences in immune response are easily demonstrated (7) . These sex differences are also seen as metabolic alterations in estrogen metabolism that occur in lupus patients of both sexes (8).
