Renal survival and prognostic factors in patients with PR3-ANCA associated vasculitis with renal involvement

Background. Severe renal disease is a feature of anti-neutrophil cytoplasmic antibodies (ANCA)-associated small-vessel vasculitis. We evaluated patient and renal survival and prognostic factors in patients with PR3-ANCA associated vasculitis with renal involvement at diagnosis during long-term follow-up. Methods. Eighty-five patients were diagnosed between 1982 and 1996 and followed until 2001 allowing greater than or equal to5 years of follow-up. All patients were treated with prednisolone and cyclophosphamide. Univariate and multivariate analyses with patient and renal survival as dependent variables were performed. Results. Of the 85 patients in this study, 17 (20%) died within one year after diagnosis. Of the 25 patients (29%) who were dialysis dependent at diagnosis, two remained dependent and two again became dialysis dependent after less than one year; nine died early without renal recovery. Risk factors for death occurring within one year in univariate analysis (RR, 95% CI) were age >65 years (6.5, 1.6-13.7) and dialysis dependency at diagnosis (3.6, 1.0-13). Twenty patients died beyond one year during the long-term follow-up. Male gender (4.7, 1.6-10) and developing dialysis dependency during follow-up (4.1, 1.4-12) were associated with poor outcome. Risk factor for renal failure within one year was dialysis dependency at diagnosis (29, 3.6-229). Of 64 patients dialysis independent one year after diagnosis, 12 patients became dialysis dependent during follow-up. A renal relapse was strongly associated with development of renal failure in long-term follow-up (17, 3.5-81). Conclusions.Early death and failure to recover renal function in P R3-ANCA associated vasculitis is associated with age >65 years and dialysis dependency at diagnosis. Long-term renal survival is determined by renal relapses during follow-up only. Slow, progressive renal failure without relapses is rarely observed in this group.