ANCA-associated vasculitis with renal involvement: an outcome analysis

Area of Science:

• Nephrology
• Rheumatology
• Immunology

Background:

• Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) encompass heterogeneous conditions.
• Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), and renal-limited vasculitis (RLV) are distinct AAV subtypes.
• Differences in outcomes between proteinase 3-ANCA (PR3-ANCA) and myeloperoxidase-ANCA (MPO-ANCA) in homogeneously treated patients with renal involvement remain under-assessed.

Purpose of the Study:

• To investigate the clinical outcomes of WG, MPA, and RLV.
• To compare outcomes between PR3-ANCA and MPO-ANCA positive patients with renal involvement.
• To identify predictors of renal survival and patient mortality in AAV.

Main Methods:

• Retrospective analysis of 80 patients with new-onset WG, MPA, or RLV and biopsy-proven renal involvement.
• Median follow-up of 46.7 months.
• All patients received induction therapy with cyclophosphamide and oral corticosteroids.

Main Results:

• 23% of patients required dialysis; renal survival was significantly worse in WG compared to MPA or RLV (P=0.04).
• PR3-ANCA positive patients had a higher rate of end-stage renal disease (ESRD) and mortality compared to MPO-ANCA positive patients.
• Mortality predictors included ESRD development, older age, and peak creatinine; PR3-ANCA positivity significantly increased mortality risk (relative risk 9.32).

Conclusions:

• ANCA type significantly influences disease severity and patient outcomes.
• PR3-ANCA is associated with a more aggressive disease course and poorer prognosis in patients with renal AAV.
• These findings underscore the pathogenetic role of ANCA in determining AAV clinical manifestations and outcomes.