INTERLEUKIN-6 AUTOANTIBODIES - POSSIBLE BIOLOGICAL AND CLINICAL-SIGNIFICANCE

The pleiotropic cytokines, interleukin (IL)-1 alpha, type I interferon s and IL-6 also act on cells involved in antibody production. Somehow the immunologic tolerance to these cytokines is often spontaneously br oken - even in healthy individuals. Thus, relatively high concentratio ns of high affinity IgG antibodies against IL-1 alpha and IL-6 frequen tly occur in the circulation of healthy adults. The autoantibodies spe cifically antagonize the respective cytokines in vitro. Thermodynamic estimations strongly suggest that autoimmunity can play a significant role in the regulation of certain cytokines. In the light of IL-6 auto antibodies the possible biological and clinical significance of cytoki ne autoimmunity is discussed.