TMP-SMX-associated acute respiratory distress syndrome with DAIDE pathology in a Korean patient lacking HLA-B*07:02 and C*07:02: A case report.

RATIONALE: Trimethoprim-sulfamethoxazole (TMP-SMX)-induced acute respiratory distress syndrome (ARDS) is a rare but potentially fatal adverse drug reaction, most commonly reported in young, otherwise healthy individuals. Although recent studies from the United States have identified a strong association with human leukocyte antigen (HLA)-B07:02 and C07:02 alleles, no cases have been reported in East Asian populations. PATIENT CONCERNS: A 37-year-old Korean male with rheumatoid arthritis-associated interstitial lung disease developed rapidly progressive dyspnea and hypoxemia after receiving TMP-SMX for Pneumocystis jirovecii polymerase chain reaction positivity. DIAGNOSES: The patient was diagnosed with TMP-SMX-induced ARDS. Surgical lung biopsy demonstrated diffuse alveolar injury with delayed epithelialization. HLA genotyping confirmed the absence of HLA-B07:02 and C07:02 alleles. INTERVENTIONS: TMP-SMX was discontinued, and the patient received maximal supportive therapy, including corticosteroids, mechanical ventilation, and venovenous extracorporeal membrane oxygenation. OUTCOMES: Despite aggressive management, the patient required prolonged extracorporeal membrane oxygenation support and was transferred for lung transplantation evaluation due to persistent severe respiratory failure. LESSONS: This case represents the first reported TMP-SMX-induced ARDS with diffuse alveolar injury with delayed epithelialization pathology in an East Asian individual, suggesting ethnic variability in HLA-associated risk alleles. The findings underscore the need for population-specific pharmacogenomic investigation in severe drug-induced lung injury.