Characteristics and Outcomes of Granulomatosis With Polyangiitis (Wegener) and Microscopic Polyangiitis Requiring Renal Replacement Therapy: Results From the European Renal Association-European Dialysis and Transplant Association Registry.

BACKGROUND: This study describes the incidence and outcomes of European patients requiring renal replacement therapy (RRT) for kidney failure due to antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: 12 renal registries providing individual RRT patient data to the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry in 1993-2012 participated. PREDICTOR: Cause of primary kidney disease: AAV (ie, granulomatosis with polyangiitis [Wegener] and microscopic polyangiitis) versus 3 separate matched control groups without AAV: (1) primary glomerulonephritis, (2) diabetes mellitus, and (3) disease other than diabetes mellitus as the cause of primary kidney disease, including glomerulonephritis (termed "nondiabetes"). OUTCOMES: Incidence, causes of death, and survival. MEASUREMENTS: ERA-EDTA primary renal disease codes. RESULTS: 2,511 patients with AAV (1,755, granulomatosis with polyangiitis; 756, microscopic polyangiitis) were identified, representing an incidence of 1.05 per million population (pmp) for granulomatosis with polyangiitis (predominating in Northern Europe) and 0.45 pmp for microscopic polyangiitis (prevailing in Southern Europe). Kidney transplantation was performed in 558 (22.2%) patients with vasculitis. The 10-year probability for survival on RRT after day 91 was 32.5% (95% CI, 29.9%-35.1%) in patients with vasculitis. Survival on RRT after day 91 did not differ between AAV and matched nondiabetes patients. Patient and transplant survival after kidney transplantation, adjusted for time period and country, was better in AAV than in matched nondiabetes patients (HRs of 0.81 [95% CI, 0.67-0.99] and 0.82 [95% CI, 0.69-0.96], respectively). LIMITATIONS: No data for extrarenal manifestations, treatment, and relapses. CONCLUSIONS: Geographical differences in the incidence of RRT for kidney failure due to granulomatosis with polyangiitis and microscopic polyangiitis copied their distribution in the general population. Overall survival on RRT after day 91 for patients with AAV was similar to that for patients with nondiabetes diagnoses. Our results suggest that patients with AAV are suitable candidates for kidney transplantation with favorable survival outcomes.

Diagnostics and therapy of antineutrophil cytoplasmic antibody (ANCA) associated vasculitides.

Granulumatosis with polyangiitis (wegener's)/GPA microscopic polyangiitis (MPA) and Churg Strauss syndrome (CSS) are primary systemic vasculitides which predominantly affect small vessels, showing a high association with a positive C/PR3-ANCA in GPA and P/MPO-ANCA in MPA, so called ANCA-associated vasculitides (AAV). The diagnostic work-up relies on an interdisciplinary approach including imaging techniques and laboratory tests in order to assess disease stage and extent. The golden standard remains the histological proof of a necrotizing, pauci-immune small vessel vasculitis, in GPA additionally non-caseating granuloma is found mainly in the respiratory tract. Treatment is adapted to disease stage and extent and relies on a combination of a cytotoxic plus a tapering regimen of glucocorticosteroids. Induction of remission in "early systemic" disease without organ- and life-threatening organ manifestations and a near normal kidney function can be achieved with methotrexate. In the generalized phase with significant renal dysfunction cyclophosphamide is the mainstay of therapy, in rapidly progressive glomerulonephritis with an imminent dialysis indication plasmapheresis is performed additionally. When remission is achieved, usually after 3-6 months of induction treatment, cyclophosphamide is switched to azathioprine as maintenance of remission drug. Alternative therapies are methotrexate provided the kidney function is normal or Leflunomide in the long-term follow-up the relapse rate in ANCA-associated vasculitis is approximately 50% in 5 years, irrespective of the drug used for maintenance treatment. The relapse rate is significantly higher in GPA than in MPA and CSS.