Mechanisms of action of intravenous immunoglobulin therapy and potential use in autoimmune connective tissue diseases.

It has been almost 10 years since the observations on the efficacy of intravenous immunoglobulin (IVIG) in patients with autoimmune thrombocytopenic purpura. Over the next decade, IVIG was used in other types of autoimmune diseases. Much work has also been done on gaining a better understanding of the mechanism(s) by which IVIG exerts its effects in these autoimmune diseases. This review examines the proposed mechanisms of action of IVIG and establishes a rationale for the use of this type of therapy in systemic lupus erythematosus (SLE) and other autoimmune connective tissue disorders. Currently, only anecdotal reports are available on the treatment of SLE with IVIG. Nevertheless, studies thus far suggest that IVIG may be useful in selected SLE patients with cytopenias and cutaneous vasculitis and may have a steroid-sparing effect in patients with SLE and juvenile rheumatoid arthritis. In SLE patients with renal disease, it should be used cautiously because some patients have worsening of their renal function with IVIG infusions. These preliminary experiences suggest that multicenter controlled trials on the therapeutic use of IVIG in SLE and other connective tissue disorders would be important.