[Treatment of ANCA-positive systemic vasculitis with intravenous immunoglobins]

ANCA positive systemic vasculitis comprises Wegener granulomatosis (WG), microscopic polyangiitis (MPA) and Churg Strauss syndrome (CSS). In WG, anti-Pr3 ANCA are present in 90% of the cases, whereas in MPA and CSS ANCA are present in 40 to 80% and 25 to 60% of the cases, respectively, with anti-MPO specificity. The treatment of WG and MPA associates prednisone and cyclophosphamide, and clinical remission is obtained in 70 to 90% of the cases. However, relapses occur in 10 to 30% of the patients and tolerance of corticosteroids and immunosuppressive therapy is not always good.

Intravenous immunoglobulins (IVIg) are well tolerated and indicated in a large number of autoimmune and systemic inflammatory diseases. In vitro IVIg specifically inhibit ANCA activity through V-region dependent interaction of anti-ANCA anti-idiotypic antibodies with ANCA. Several open studies and a few case reports of patients with WG or MPA treated with IVIg were published in the past seven years, with various results.

A prospective controlled multicenter study is necessary to evaluate the efficacy of IVIg in the treatment of ANCA positive vasculitides.