Emerging role of stem cell memory-like T cell in immune thrombocytopenia.

Immune thrombocytopenia (ITP) is an acquired autoimmune disease characterized by autoantibody-mediated platelet destruction. Multiple factors have been implicated in ITP pathogenesis, including T-lymphocyte dysfunctions. Increasing studies have indicated that stem cell memory-like T cell (TSCM) plays an important role in the development of multiple autoimmune diseases. This study aimed to explore the clinical correlation between the TSCM subset and ITP. The percentages of peripheral blood naïve T cells (TNs), TSCMs, central memory T cells (TCMs), effector memory T cells (TEMs) and effector T cells (TEs) among CD4+ and CD8+ T cells in 20 ITP patients before and after treatment were detected using flow cytometry. Our results showed that the percentages of peripheral blood CD4+ and CD8+ T cells in ITP patients were imbalanced. The percentage of CD8+ TSCMs in peripheral blood before treatment in ITP patients was significantly higher than that in healthy controls, whereas the percentages of the other T cell subsets did not exhibit significant differences. Our study further analysed the correlation between the change in the percentage of CD8+ TSCMs and the treatment efficacy. The results showed that the percentage of peripheral blood CD8+ TSCMs in ITP patients after glucocorticoid treatment significantly decreased and the changes of the percentages of CD8+ TSCMs before and after treatment in complete response (CR) and response (R) patients were obvious. Our finding showed that the imbalance of the percentage of CD8+ TSCMs might be involved in the development of ITP and might serve as a novel indicator of efficacy.

[Clinical Efficacy of Humanized Anti-CD19 Chimeric Antigen Receptor T Cells in the Treatment of Acute B Lymphocytic Leukemia].

OBJECTIVE: To study the safety and effectiveness of humanized CD19-targeted CAR-T cells (hCART19s) for treatment of patients with refractory/relapsed (R/R) B-ALL. METHODS: The analyzed patients were 15 children and adults with relapsed/refractory B-ALL who not received treatment with murine CD19 CAR-T cells. The patients received a single dose (1×106/kg) of autologous hCART19 infusion after lymphodepletion chemotherapy based on cyclophosphamide and fludarabine. RESULTS: Among the 15 patients, 13/14 (92.9%) evaluable patients achieved complete remission (CR) or CR with incomplete recovery of blood cells (CRi) on day 30 after hCART19s infusion. At day 180 after the infusion, the overall survival rate was 73.3%, and the leukemia-free survival rate was 69.2%. The cumulative incidence of relapse was 24.5% and non-relapse mortality rate was 7.7%. During treatment,12/15 patients (80%) developed cytokine release syndrome (CRS) of grade 1-2, and 3 patients (20.0%) developed CRS of grade 3-5. Only one patient (6.7%) suffered from the reversible neurotoxicity. CONCLUSION: hCART19s can effectively treat refractory/relapsed (R/R) adult and children with B-ALL, and the incidence of treatment-related CRS and neurotoxicity is low.