Blood monocyte count is a predictor of total and cardiovascular mortality in hemodialysis patients

An increase in white blood cell (WBC) count is an independent predictor of mortality in hemodialysis (HD) patients. However, few studies have assessed the association of specific WBC subtypes with mortality. We prospectively studied the predictive value of WBC subtypes for total and cardiovascular death in 333 HD patients (age 63 +/- 12 years; HD duration 129 +/- 109 months) during a 40-month of follow-up. There was a significant and positive correlation between highly sensitive C-reactive protein and neutrophil (r = 0.28, p < 0.01) and monocyte (r = 0.20, p < 0.01) counts by a non-parametric Spearman rank analysis. Blood monocyte counts were significantly correlated inversely with ankle-brachial pressure index (r = -0.24, p < 0.01). Kaplan-Meier analysis revealed that basal neutrophil (>4,060/microl) and monocyte (>270/microl) counts in the highest tertile had a significantly lower survival rate compared to the middle and the lowest tertiles, respectively (p < 0.03). Cox hazards analysis after adjustment for other conventional risk factors revealed that monocyte counts of >270/microl became a determinant of total death compared with those of <180/microl (hazards ratio 1.98 [1.10-3.57], p = 0.02). In contrast, neutrophil and lymphocyte counts were not associated with mortality. Our findings suggest that an increased blood monocyte count is an independent predictor of long-term mortality in chronic HD patients.