TY  - JOUR
A1  - Peinelt, Andreas
A1  - Bremm, Melanie
A1  - Kreyenberg, Hermann
A1  - Cappel, Claudia
A1  - Banisharif-Dehkordi, Julia
A1  - Erben, Stephanie
A1  - Rettinger, Eva
A1  - Jarisch, Andrea
A1  - Meisel, Roland
A1  - Schlegel, Paul-Gerhardt
A1  - Beck, Olaf
A1  - Bug, Gesine
A1  - Klusmann, Jan-Henning
A1  - Klingebiel, Thomas
A1  - Hünecke, Sabine
A1  - Bader, Peter
T1  - Monitoring of circulating CAR T cells: validation of a flow cytometric assay, cellular kinetics, and phenotype analysis following tisagenlecleucel
T2  - Frontiers in immunology
N2  - Chimeric antigen receptor (CAR) T cell therapy is a potent new treatment option for relapsed or refractory hematologic malignancies. As the monitoring of CAR T cell kinetics can provide insights into the activity of the therapy, appropriate CAR T cell detection methods are essential. Here, we report on the comprehensive validation of a flow cytometric assay for peripheral blood CD19 CAR T cell detection. Further, a retrospective analysis (n = 30) of CAR T cell and B cell levels over time has been performed, and CAR T cell phenotypes have been characterized. Serial dilution experiments demonstrated precise and linear quantification down to 0.05% of T cells or 22 CAR T cell events. The calculated detection limit at 13 events was confirmed with CAR T cell negative control samples. Inter-method comparison with real-time PCR showed appreciable correlation. Stability testing revealed diminished CAR T cell values already one day after sample collection. While we found long-term CAR T cell detectability and B cell aplasia in most patients (12/17), some patients (5/17) experienced B cell recovery. In three of these patients the coexistence of CAR T cells and regenerating B cells was observed. Repeat CAR T cell infusions led to detectable but limited re-expansions. Comparison of CAR T cell subsets with their counterparts among all T cells showed a significantly higher percentage of effector memory T cells and a significantly lower percentage of naïve T cells and T EMRA cells among CAR T cells. In conclusion, flow cytometric CAR T cell detection is a reliable method to monitor CAR T cells if measurements start without delay and sufficient T cell counts are given.
KW  - acute lymphoblastic leukemia
KW  - chimeric antigen receptor (CAR)
KW  - flow cytometry
KW  - immune monitoring
KW  - immunotherapy
Y1  - 2022
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/81402
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-814028
SN  - 1664-3224
N1  - This project was supported by “Frankfurter Stiftung für krebskranke Kinder”, “Hilfe für krebskranke Kinder Frankfurt e.V.”, and “Frankfurter Promotionsförderung Promotionsstipendium” (F54/2020; R254/2020).
VL  - 13
IS  - art. 830773
SP  - 1
EP  - 12
PB  - Lausanne
CY  - Frontiers Media
ER  -