Under Pressure: Rethinking Plasma Exchange in the Management of ANCA-Associated Vasculitis with Alveolar Hemorrhage

Introduction: Diffuse alveolar hemorrhage (DAH) is a life-threatening ANCA-associated vasculitis (AAV) manifestation that often occurs with crescentic necrotizing glomerulonephritis. Plasma exchange (PLEX) is commonly used as rescue therapy, despite limited evidence of efficacy. Case Description: Three white females (mean age 42 years) with AAV, DAH and acute kidney injury, baseline creatinine 0.83 (0.07) mg/dL, were hospitalized with admission creatinine ranging from 1.51–2.85 mg/dL, rising to 2.85–5.96 mg/dL. One patient required renal replacement therapy. All showed active urinary sediment, elevated inflammatory markers (CRP 107.9–244 mg/L; ESR >80 mm/h), and positive ANCA titers: PR3 2.9 IU/mL (n=1), PR3 >8 (n=1), MPO >8 (n=1). Kidney biopsy was performed in two patients. Immunosuppressive therapy included high-dose glucocorticoids, Rituximab, and Avacopan (Table 1). All patients experienced recurrent DAH, prompting consideration of PLEX. DAH was diagnosed based on clinical-radiological findings and bronchoalveolar lavage. All required temporary oxygen supplementation. At the time of DAH, patients exhibited signs of hemodynamic overload, with a median weight of 80.4 [70.6, 116.7] kg and median mean blood pressure of 111 [108.2, 111.7] mmHg. Instead of PLEX, hemodynamic correction through fluid removal and pressure adjustment was initiated, resulting in a median weight reduction of 10.6 [7.07, 12.12] kg and a median decrease of mean blood pressure of 30 [26.17, 33.67] mmHg with complete resolution of DAH. Discussion: DAH in AAV may appear refractory despite maximal immunosuppression, leading to consideration of PLEX. These cases suggest that hemodynamic derangements, rather than sustained immunologic activity, may underlie persistent or recurrent DAH, which may require meticulous fluid and blood pressure optimization instead of PLEX.