LAUSR

Background. Hemodialysis (HD) patients have an increased risk of thrombosis. Endothelial progenitor cells (EPCs), which function in vascular repair, are deficient in HD patients. Nonetheless, the relationship between EPC deficiency and thrombosis in HD patients is unknown. Methods. From January 2010 to December 2012, circulating levels of EPCs that were positive for CD34 and kinase insert domain receptor (KDR) were measured in 269 HD patients. Patients received prospective follow‐ups at 6‐month intervals until May 2015. The primary outcome was the composite of HD access thrombosis and systemic vascular thrombosis. Results. There were 141 thrombotic events, 50 systemic vascular thrombotic events and 116 HD access thrombotic events. We found significantly negative associations between CD34+ KDR+ tertile and overall thrombotic events (low: 61%; middle: 56%; high: 40%; P = 0.02), systemic vascular thrombotic events (low: 27%; middle: 18%; high: 10%; P = 0.03) and HD access thrombotic events (low: 52%; middle: 46%; high: 36%; P = 0.02). Univariate analysis indicated that systemic vascular thrombotic events were positively associated with age, diabetes, dyslipidemia, vascular disease history, urea clearance, albumin and C‐reactive protein (CRP), and negatively associated with CD34+ KDR+ cell count. HD access thrombosis was positively associated with vascular disease history and CRP, and negatively associated with CD34+ KDR+ cell count. Multivariate analysis indicated that a low CD34+ KDR+ cell count was an independent risk factor for both types of thrombosis. Conclusions. Our study of a population of HD patients showed that a low level of circulating EPCs is associated with thrombosis.