Avacopan-Assisted Remission of Diffuse Alveolar Hemorrhage in Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Case Report.

Myeloperoxidase (MPO)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) can present with diffuse alveolar hemorrhage (DAH), a life-threatening pulmonary complication, even in the absence of renal involvement. Relapse and steroid-related toxicity remain significant management challenges in such cases. Avacopan, a selective complement C5a receptor antagonist, has been introduced as a steroid-sparing agent; however, its role in pulmonary-dominant MPO-AAV remains underreported. Here, we describe a 24-year-old woman from Medina, Saudi Arabia, who presented with life-threatening DAH and acute hypoxemic respiratory failure secondary to MPO-AAV. She initially responded to pulse intravenous methylprednisolone and intravenous immunoglobulin but suffered an early relapse during treatment, and rituximab was therefore initiated. Due to steroid dependence and recurrent respiratory decline, avacopan 30 mg twice daily was started as an adjunctive therapy. Following sustained clinical remission for more than six months, corticosteroids were withdrawn, and the patient had no recurrence of DAH or further respiratory compromise. This case highlights the therapeutic value of avacopan as a steroid-sparing adjunct in MPO-AAV with severe pulmonary involvement. This is the first reported case from Saudi Arabia of avacopan use in MPO-AAV with predominantly pulmonary involvement, underscoring the need for regional real-world evidence to guide its optimal use in this challenging phenotype.