ANCA anti-idiotype antibodies and the treatment of systemic vasculitis with intravenous immunoglobulin.

The presence of anti-idiotype antibodies (anti-id) to anti-neutrophil cytoplasm autoantibodies (ANCA) in intravenous immunoglobulin (IVIg) and remission sera from patients with systemic vasculitis, and the use of IVIg as an alternative therapeutic agent in open studies, has suggested a role for idiotypic regulation in the normal control of these disorders. Clinical benefit with IVIg has been reported in 15/16 patients, with sustained remission in eight. The ability of IVIg to produce lasting remission has been associated with a fall in ANCA levels and stimulation of endogenous immunoglobulin production. IVIg has the potential to influence the pathogenetic process in patients with vasculitis at several stages, and an influence on the idiotypic regulation of ANCA may explain the observed clinical responses and point to possible targets for more specific immunotherapy in the future.