Diffuse alveolar hemorrhage in ANCA-associated vasculitis: Current evidence and multimodal treatment approaches.

Diffuse alveolar hemorrhage (DAH) is a rare but life-threatening complication of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), with management largely extrapolated from broader AAV and ARDS literature. We conducted a review of studies published between 2000 and 2025 evaluating treatments and outcomes in AAV-associated DAH, synthesizing evidence across immunosuppressive, plasmapheresis, hemostatic, respiratory and hemodynamic, and infection prevention strategies. Glucocorticoids combined with rituximab or cyclophosphamide induce remission in most patients, although optimal steroid tapering and comparative efficacy in severe, ventilated DAH remain uncertain. Avacopan improves sustained remission and renal recovery in severe AAV and appears to be a feasible steroid-sparing adjunct in early DAH series. Large randomized trials demonstrate no survival benefit of plasma exchange. Local hemostatic therapies may provide rapid bleeding control, but evidence is limited. Respiratory outcomes are driven by hypoxemia severity and need for invasive ventilation or extracorporeal support. Lastly, infection prevention measures are strongly supported.