Platelet and Monocyte Activity Markers and Mortality in Patients with End-Stage Renal Disease.

Background: The association of platelet and monocyte activity markers with long-term mortality was assessed in hemodialysis (HD) patients. Methods: In 41 HD patients (25 male, 16 female), surface expression of CD40L and CD62P on platelets, tissue factor (TF) binding on monocytes, and platelet-monocyte aggregates were measured by flow cytometry. Plasma levels of MCP-1, IL-6, TNF alpha, and soluble CD40L were analyzed by enzyme linked immunosorbent assay. Cox proportional hazard regression analyses and Kaplan-Meier curve were calculated. The predefined endpoint was all-cause mortality. Results: The study follow-up was 11.54 years. Thirty-one patients (75.6%) died within the study period. Mean patient survival after study inclusion was 5.45 +/- 4.24 years. TF on monocytes above the median of the study population was significantly and independently associated with total mortality (HR (95% CI) 3.45 (1.32 - 9.07); p = 0.01). Cumulative mortality in patients with TF on monocytes above median was significantly higher compared to patients with TF on monocytes below median value (log rank p < 0.01). Platelet-monocyte aggregates, the expression of CD40L and CD62P on platelets, and plasma levels of sCD40L, IL-6, MCP-1, and TNFu were not significantly correlated with mortality. Conclusions: The present study confirms a high mortality in ESRD patients. TF binding on monocytes was significantly correlated with increased mortality and may identify a subgroup of patients at higher risk.