Complex Challenges in ANCA-Associated Vasculitis: A Case of COVID-19, Cytomegalovirus Pneumonitis, and Hemorrhagic Cholecystitis Following Rituximab Therapy.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare autoimmune disease with significant infectious and hemorrhagic risks during immunosuppressive therapy. We describe an 81-year-old woman with perinuclear ANCA (p-ANCA)-associated vasculitis complicated by acute respiratory distress syndrome from concurrent COVID-19 and CMV pneumonitis following rituximab induction. Her course was further complicated by hemorrhagic cholecystitis, a rare bleeding manifestation, requiring percutaneous intervention. Careful adjustment of immunosuppression was necessary due to severe infections. This case highlights the complexity of managing AAV amid severe infections and rare hemorrhagic complications, emphasizing the need for vigilant monitoring and individualized therapy.