A robust adoptive cell therapy phenotyping panel for assessing cerebrospinal fluid during and after neurotoxicity by flow cytometry

CYTO 2023 -- Chimeric antigen receptor T-cells (CAR-T) are an exciting area of therapeutics that are rapidly expanding into broader disease indications with the development of increasingly sophisticated and elegant CAR-T designs. Despite impressive remission rates in many disease indications, a high percentage (5-40%) of treated patients are often plagued with neurotoxicities that can be mild to life threatening in severity. The complete mechanisms are not fully understood, but a hallmark is increased permeability of the blood-brain barrier, allowing immune cells, including infused CAR-T, to potentially accumulate in cerebrospinal fluid (CSF). Understanding which immune cells are accumulating in the CSF could help in the development of newer and safer therapies and mitigation strategies. We have developed a flow cytometry backbone assay for measuring T-cell, B-cell, NK cell, monocyte and granulocyte populations in CSF samples with expected low cellularity. Inclusion of an interchangeable CAR-T phenotyping channel is available for drug specific CAR-T detection as well.