High neutrophils and low CD34+ cell count are associated with increased risk of venous thromboembolism

Purpose: The relationship between Metabolic Syndrome (MetS), levels of circulating progenitor/immune cells and the risk of Venous Thromboembolism (VTE) has not been investigated. Methods and results: We studied 240 patients with previous VTE and 240 controls. Presence of MetS was identified according to NCEP ATP III guidelines and flow cytometry was used to quantify circulating CD34+ cells. VTE patients showed higher BMI, waist circumference, triglycerides levels, blood glucose, hs-CRP and lower HDL cholesterol levels. The prevalence of MetS was significantly higher in VTE (38,3%) than in control individuals (21,3%) with an adjusted odd ratio for VTE of 1,96 (p=0.002). VTE patients had higher circulating neutrophils (p<0.0001), while the CD34+ cell count was significantly lower among patients with unprovoked VTE compared to both provoked VTE (p=0.004) and controls (p=0.003). Subjects were also grouped according to presence/absence of MetS (MetS+ or MetS -) and the level (high/low) of both CD34+ cells and neutrophils. Very high adjusted odd ratios for VTE were observed among neutrophils\_high/Met+ (OR 3.58, p<0.0001) and CD34+\_low/MetS+ (OR 3.98, p<0.0001) subjects as compared to the neutrophils\_low/MetS- and CD34+\_high/MetS- groups respectively. Conclusions: Low CD34+ blood cell count and high circulating neutrophils interplay with MetS in raising the risk for venous thromboembolic events.