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.