Objectives: This prospective study sought to assess the long-term outcome and identify prognostic factors of patients with kidney disease related to Wegener's granulomatosis (WG).
Methods: Of 50 patients with newly diagnosed WG who were enrolled between 1990 and 1993 in a trial comparing IV and oral cyclophosphamide (CYC), 37 had renal disease, either histologically proven or diagnosed based on laboratory findings. Their principal demographic, laboratory and therapeutic data, and progression to end-stage renal disease and/or death (ESRD) provided a basis for survival analysis, using Cox proportional hazards models.
Results: Of the 37 patients (M/F ratio, 23/14; mean age, 55.1+/-12.1 years; antineutrophil cytoplasm antibody-positivity, 97%; ear-nose-throat involvement, 75%; pulmonary involvement, 78%; IV/oral CYC, 23/14), 36 had glomerulonephritis and one had a granulomatous renal tumor; 22 (59%) had initial serum creatinine levels >150 micromol/L. During a mean follow-up of 6.4+/-4.7 years, 15 (41%) patients died and two developed ESRD (10-year dialysis-free survival: 51+/-17%). Only one of the nine patients with renal relapses was alive without ESRD at the end of the study. According to uni- and multivariate analyses, dialysis-free survival was significantly shorter for patients with initial serum creatinine >150 micromol/L (10-year dialysis-free survival, 24+/-18% versus 89+/-21%) (hazard ratios=20.2 and 21.7; P<0.005), while the initial route of CYC administration did not influence outcome.
Conclusion: These observations confirm the poor survival and functional outcome associated with renal involvement of WG and highlight the strong prognostic impact of renal function at diagnosis and of renal relapses during follow-up. Conversely, the initial route of CYC administration appears to have no effect on survival.