Evaluation of the BCA and cytokine profile according to CRS grading. (A) The kinetics of circulating CD19⁺ cells was monitored over time in the PB in all the treated patients by flow cytometry. BCA was defined according to the criteria established in the ELIANA phase 2 trial, namely as <3% B lymphocytes in total PB leukocytes (or absolute count of <50/μL) or <1% of CD19⁺ B cells in the BM.¹⁵ (B) The peak levels of the 4 most relevant cytokines (IFN-γ, IL-10, IL-6, and TNF-α) were measured in the sera of each treated patient and correlated with the severity of the CRS. (C) The percentage of blasts in the BM at lymphodepletion, evaluated by flow cytometry, was correlated with the severity of the CRS experienced by patients after infusion of CD19-CAR_Lenti cells. IFN-γ, interferon gamma; PD, progressive disease; TNF-α, tumor necrosis factor α.