Serologic and Clinical Response to Treatment of Systemic Vasculitis and Associated Autoimmune Disease with Intravenous Immunoglobulin

Background: Autoimmune vasculitides cannot always be controlled by steroids and immunosuppressive drugs. Intravenous immunoglobulin (IVIg) treatment was found beneficial in several vasculitides including systemic and organ–specific diseases. In this article we tested whether the beneficial clinical response of IVIg treatment in vasculitides was accompanied by a decrease in vasculitis–associated autoantibody levels. Methods: Ten patients diagnosed as having vasculitis were treated with high–dose (2 g/kg) IVIg monthly, in a 5–day schedule. In all the patients, other therapeutic measures failed to control disease progression prior to IVIg treatment. Each patient received between 1 and 6 treatment courses. All patients were evaluated for the levels of 5 autoantibodies (Abs) related to vasculitis before and after each treatment course. Results: In 6 out of the 10 patients, a beneficial clinical response followed IVIg treatment. Moreover, no treatment–related adverse effects were observed in any of the patients. Anti–myeloperoxidase antibodies and cytoplasmic–antineutrophil cytoplasmic antibodies levels decreased concomitantly with the clinical improvement observed in the patients with Churg–Strauss vasculitis and Wegener’s granulomatosis, respectively. Levels of cytoplasmic–antineutrophil cytoplasmic antibodies (ANCA) with specificity for bacteridial/permeability–increasing protein and human lysosomal–associated membrane protein increased after each treatment course, but returned to normal values before the following one. Conclusions: When other therapeutic measures, such as immunosuppressive therapy, fails to control disease manifestations in patients with vasculitides, IVIg is a possible effective intervention method with a high response rate. IVIg probably exerted its effects on disease progression via different mechanisms. Among these mechanisms, a decrease in relevant Ab levels is often found (probably by anti–idiotypes in IVIg), and thus ANCA levels are expected to associate with disease activity.