Management of Cytokine Release Syndrome (CRS) and HLH

Abstract Cytokine release syndrome (CRS) is caused by a rapid and mild to massive release of cytokines from immune cells involved in immune reactions, particularly after immunotherapy. The frequency and severity of CRS after CAR-T cell therapy varies between products (any grade: 37–93%, G3/4: 1–23%) (Neelapu et al. 2017; Schuster et al. 2019; Abramson et al. 2020).