Clinical course and symptomatic prediagnostic period of patients with Wegener's granulomatosis and microscopic polyangiitis.

The clinical course of 15 patients with Wegener's granulomatosis (WG) and eight patients with microscopic polyangiitis (MPA) from one nephrological clinical center is presented for the period from 1984 to 1993, when testing for antineutrophil cytoplasmic antibodies (ANCA) was gradually introduced into routine clinical practice. We found a high degree of prolonged time periods with symptoms attributable to WG or MPA until the specific diagnosis was made. Nine patients with WG and one patient with MPA had symptomatic prediagnostic periods of more than three years, which extended in one case up to twenty years. In these prediagnostic periods, often even severe flares of vasculitic activity resulted in spontaneous remission without immunosuppressive therapy. One patient on chronic dialysis for four months because of rapidly progressive glomerulonephritis, experienced sufficient spontaneous regain of residual renal function to stay off dialysis for 6 years. Despite a high amount of spontaneous recovery, recurrent flares of disease eventually led to death in those cases without sufficient immunosuppressive therapy. Contrary to long courses of disease, one patient with WG had a fulminate exacerbation of disease with lethal hemoptysis after a prediagnostic period of only three months. Renal disease, respiratory and other symptoms did not occur sequentially, but each could precede the other. We conclude in agreement with published former experience, that WG and MPA show a highly variable spontaneous disease course, that requires extended observational periods for evaluating maintenance therapies.