Key clinical point: Inhibition of T cells by programmed death-ligand 1 (PD-L1)-expressing hematopoietic stem cells could be an underlying mechanism in the development of myelodysplastic syndrome (MDS). The findings support the potential use of immune checkpoint inhibitors in the treatment of suitable MDS patients.
Major finding: Significantly increased proportions of PD-L1 +CD34+ stem cells were seen in MDS patients compared with hematopoietic stem cell transplantation (HSCT) recipients in remission for both the CD38 − subset ( P = .0127) and CD38 + subset ( P = .0336).
Study details: The study included 7 MDS and 9 acute myeloid leukemia samples. Six HSCT recipients who remained in remission for more than 6 months were considered controls.
Disclosures: The study was supported by the Düsseldorf School of Oncology (funded by the Comprehensive Cancer Center Düsseldorf/Deutsche Krebshilfe and the Medical Faculty HHU Düsseldorf). The authors declared no conflicts of interest.
Source: Moskorz W et al. Br J Haematol. 2021 May 6. doi: 10.1111/bjh.17461 .