Methods
We performed a retrospective analysis of all patients who received multiple infusions of a non-humanized CD19-directed 4-1BB CAR-T, tisagenlecleucel, at Cincinnati Children’s Hospital Medical Center between January 2018 and December 2021. This study was approved by the Cincinnati Children’s Hospital Medical Center Institutional Review Board. A comprehensive review of patient, disease, and product characteristics, toxicities, and patient outcomes was performed. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were graded according to the American Society of Transplantation and Cellular Therapy consensus guidelines.16 Remission status was tested via multiparametric flow cytometry on bone marrow samples collected 28 days following CAR-T infusion, as well as morphological cerebrospinal fluid (CSF) analysis via lumbar puncture. BCA was monitored at least monthly by peripheral blood analysis of lymphocyte subpopulations. Loss of BCA was defined as >1% CD19+ or 100 absolute CD19+ cells on peripheral analysis, confirmed on a subsequent sample.