Cytokine release syndrome and relevant factors of CD19 targeted chimeric antigen receptor T cell therapy in relapsed/refractory B cell hematological malignancies.

OBJECTIVES AND METHODS: We reviewed the outcomes of 77 episodes of CD19 CAR-T therapy in 67 patients with B cell hematological malignancies from October 2016 to January 2020. Factors related to the grade of cytokine release syndrome (CRS) were explored by multivariate analysis, nonparametric test was conducted to explore the correlation between CRS and response. Kaplan-Meier curves were used to indicate survival profiles, and the correlation between CRS and survival was determined by the log-rank test. RESULTS: The rate of complete remission (CR) was 74.0% (57/77). CRS of any grade occurred in 68 of 77 episodes (grade 1: 32.5%, grade 2: 24.7%, grade 3: 22.1%, grade 4: 6.5%, grade 5: 2.6%). Patients with a history of transplantation had less severe CRS, and dose escalation-based infusion reduced the severity of CRS. Severe CRS was related to a higher CR rate but had no significant impact on event-free survival (EFS), relapse-free survival (RFS), or overall survival (OS). CONCLUSION: As a common adverse reaction of CAR-T therapy, the severity of CRS can be alleviated by dose escalation infusion, a history of transplantation was correlated with less severe CRS. Severe CRS was related to better response but was unrelated to long-term survival.

[Effect of Chidamide on the Killing Acitivity of NK Cells Targeting K562 Cells and Its Related Mechanism In Vitro].

OBJECTIVE: To investigate the effect of chidamide on the killing activity of NK (Natural killer cell, NK) cells targeting K562 cells and its related mechanism. METHODS: K562 cells were pretreated with chidamide at different concentrations and cocultured with NK cells at different effect-target ratios. The killing effect of chidamide on K562 cells by NK cells, the expression of natural killer group 2 member D (NKG2D) ligands and apoptosis rate of K562 cells were detected by flow cytometry. RESULTS: The killing sensitivity of NK cells to K562 cells could be enhanced by chidamide. The expression of ULBP2 on K562 cell surface could be up-regulate, however, the expression of ULBP1 and MICA/MICB showed no statistically difference as compared with control group. Chidamide showed no obvious cytotoxicity to K562 cells. CONCLUSION: Chidamide can significantly improve killing efficiency of NK cells on K562 cells, which may be related to the up-regulation of ULBP2 expression.