Fatal Diffuse Alveolar Hemorrhage (DAH) Secondary to Monoclonal Antibody Therapy in a Young Patient with Ulcerative Colitis (UC): An Autopsy Case

Pulmonary complications are frequently observed in patients with ulcerative colitis (UC), with large airway disease being the most prevalent manifestation. In this case study, we explore the potential for Immunosuppressant, a monoclonal antibody, to induce pulmonary hemorrhage—a side effect not previously documented with its use. The subject, a young male in his twenties with a six-year history of UC, tragically died suddenly. Found in a pool of blood without external injuries, extensive post-mortem examinations were required to determine the cause of death. The patient had been on biologic therapy, receiving Immunosuppressant intermittently over the past two years, including an infusion five days prior to death. External examination revealed bloody, pinkish foamy material expelling from his nose and mouth. An autopsy supported an atypical presentation of UC, while histopathology confirmed diffuse pulmonary hemorrhage, marked by edema and emphysematous changes. Additionally, there was a notable lymphomonocytic infiltration around the arterial walls, and signs of bronchiolitis and focal pleural fibrosis were evident. We concluded that the cause of death was Diffuse Alveolar Hemorrhage (DAH), directly associated with the recent administration of Immunosuppressant. This finding underscores the need for vigilant pulmonary monitoring in patients treated with monoclonal antibodies to promptly identify and manage potential fatal adverse reactions.