Cytokine Release Syndrome
A systemic inflammatory response triggered by rapid release of cytokines from immune cells, potentially causing fever, hypotension, and organ dysfunction. While more commonly associated with immunotherapy, cytokine release is a theoretical concern with any biologic that strongly activates immune pathways.
Technical Context
CRS involves systemic release of pro-inflammatory cytokines (IL-6, IL-1, TNF-α, IFN-γ) from activated immune cells. Grading: Grade 1 (fever only), Grade 2 (fever + hypotension responsive to fluids, hypoxia responsive to low-flow O2), Grade 3 (fever + hypotension requiring vasopressors, hypoxia requiring high-flow O2), Grade 4 (life-threatening, ventilator support needed). CRS is most commonly associated with CAR-T cell therapy, bispecific antibodies, and checkpoint inhibitors rather than peptide drugs. However, any biologic that activates immune cells or complements carries theoretical CRS risk. For peptide drugs with immune-modulating properties (corticotropin, cyclosporine, glatiramer acetate, motixafortide), CRS is a theoretical safety consideration monitored in clinical trials, though clinically significant CRS with approved peptide drugs is rare.