Interleukin-6 in autoimmune disorders.

Interleukin-6, a pleiotropic cytokine, appears to play a key role as a physiologically functioning molecule in host defense mechanisms. Previous reports have suggested that dysregulated interleukin-6 production may be involved in lymph node hyperplasia, plasmacytosis, immunoglobulin hyperproduction, thrombocytosis, mesangial cell proliferation and acute phase response, all of which are frequently observed in autoimmune disorders. In this report, we discuss the possible involvement of interleukin-6 in the pathogenesis of a variety of autoimmune diseases and the regulatory mechanism of expression of the interleukin-6 gene.