Cytokine Release Syndrome in Hematology

Cytokine release syndrome occurs after activation of effector cells with massive release of interleukin six, interferon gamma, tumor necrosis factor, and other cytokines causing fever, hypotension, hypoxia, and organ dysfunction. Onset within hours to days of CAR T cell infusion, blinatumomab, or bispecific antibody therapy and severity often correlates with tumor burden.

Grading uses ASTCT consensus where grade one has fever only, grade two adds hypotension responsive to fluids or low oxygen support, grade three needs vasopressors or significant oxygen, grade four needs multiple vasopressors or mechanical ventilation. Concurrent immune effector cell associated neurotoxicity syndrome should be assessed by ICE score and managed separately.

Management depends on grade: supportive care and antipyretics for grade one, tocilizumab eight milligrams per kilogram for grade two and beyond, corticosteroids for refractory or grade three or four cases, anakinra or siltuximab for tocilizumab refractory disease, and intensive care unit transfer for hemodynamic or respiratory deterioration. Prevention includes prophylactic tocilizumab in high risk protocols and tumor burden reduction before infusion.