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Cytokine release syndrome (CRS) grading

ASTCT consensus grade of CRS from fever, hypotension and hypoxia.

Cytokine release syndrome (CRS) grading
Fever >=38 C (at or since onset)
Hypotension
Hypoxia / oxygen requirement
ResultNo CRS

No fever, hypotension or hypoxia attributable to CRS.

When to use

  • Grading CRS severity after CAR T-cell or other T-cell-engaging immunotherapy to guide tocilizumab and supportive care.

Formula

Fever >=38 C is required for grade 1. Grade is then set by the more severe of hypotension and hypoxia: grade 2 (fluid-responsive hypotension and/or low-flow O2), grade 3 (one vasopressor and/or high-flow O2/mask), grade 4 (multiple vasopressors and/or positive-pressure ventilation).

Pearls and pitfalls

  • After antipyretics or tocilizumab, grade is driven by hypotension/hypoxia even if fever has resolved.
  • Vasopressin is excluded when counting vasopressors for grade 4.

References

  1. Lee DW, Santomasso BD, et al. Biol Blood Marrow Transplant. 2019;25(4):625-38.