Severe Cytokine Release Syndrome After CAR T Cell Therapy in a Pediatric Patient With Relapsed ALL

Background: Cytokine release syndrome (CRS) is a potentially life-threatening complication of chimeric antigen receptor (CAR) T cell therapy, particularly in pediatric relapsed acute lymphoblastic leukemia (ALL). Case Presentation: A 7-year-old boy with early bone-marrow relapse of hypodiploid ALL received anti-CD19 CAR T cells and developed severe CRS with persistent fever, hypotension, hypoxemia, encephalopathy, and multiorgan dysfunction requiring pediatric intensive care. Management: He received tocilizumab, high-dose dexamethasone, continuous intravenous (IV) anakinra, and emapalumab, plus advanced supportive care (mechanical ventilation, vasopressors, and continuous renal replacement therapy). Sequential, multiagent immunomodulation was associated with transient hemodynamic stabilization. Conclusion: This case highlights practical bedside sequencing and escalation for refractory pediatric CRS and suggests a potential role for continuous IV anakinra and emapalumab when first-line therapy is inadequate.