Photo Credit: Md Babul Hosen

Myeloid-derived suppressor cells (MDSCs) are increased in the circulation and in the spleen of patients with primary myelofibrosis (PMF) and strongly correlate with disease progression, according to findings published in Cancers. Further, decreased CXCR4 expression on MDSCs along with higher plasmatic SDF-1α can be involved in mobilization. Researchers examined the presence of circulating MDSCs in patients with PMF, the plasmatic factors involved in mobilization/expansion, and correlations with laboratory, genetic, and clinical markers. The study included 41 patients with PMF and 21 healthy controls. MDSC subsets were identified as CD11b+CD15+Lox1+ (polymorphonuclear myeloid-derived suppressor cells [PMN-MDSCs]) or CD11b+HLA-DR^low/−CD15−CD14+ (M-MDSCs). Contrary to prior studies, investigators found that only the subset of PMN-MDSCs was “significantly increased and consistent” in patients with PMF compared with controls, while the M-MDSC subset was like controls and “hardly detectable.” The findings indicate that circulating MDSCs may be a parameter of disease severity and establish MDSCs as potential new therapeutic targets.