Correlation between increased circulating endothelial progenitor cells and stage of non-Hodgkin lymphoma.

This study aims to examine the levels of circulating endothelial progenitor cells (cEPCs) in the peripheral blood of patients with non-Hodgkin lymphoma (NHL) and their correlation with the tumor stage. Forty-one patients with biopsy-proven NHL and 16 healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation, and cEPCs were characterized by triple staining using antibodies against CD133, CD34 and vascular endothelial growth factor receptor-2 (VEGFR-2, CD309) and quantified by flow cytometry. In NHL patients, the number of cEPCs was significantly greater than in control group (P=0.000). The cEPCs counts in patients with NHL of stage III-IV were significantly greater than in stage I-II (P=0.010). FACS analysis revealed that the number of cEPCs in NHL patients had no correlation with the gender (P=0.401) or the pathological category (P=0.852). It was suggested that the over-expression of cEPCs in NHL patients may serve as a novel biomarker for disease progression in NHL.