Increased leukocyte aggregates are associated with atherosclerosis in patients with hemodialysis

Little data are available on the role of blood rheology in atherosclerosis in hemodialysis (HD) patients. This study sought to assess the relationship between leukocytes conjugated with platelets (leukocyte aggregates [LA]) and atherosclerosis in patients with HD. The present study included 118 patients on HD. As surrogate markers of atherosclerosis, aortic stiffness measured by brachial-ankle pulse wave velocity, and carotid intima-media thickness (IMT) were measured. As an assessment of LA, a method, microchannel array flow analyzer, which makes it possible to directly observe the flow of blood cell elements through the microchannel, was used. We measured a number of LA during 50 mu L flow of whole blood through microchannels. In 12 age-matched healthy individuals, a number of LA during 50 mu L flow of whole blood was 25.7 +/- 5.4, whereas in HD patients it was significantly increased up to 48.2 +/- 16.4 (P < 0.001). Flow cytometry demonstrated that LA were predominantly monocytes. Leukocyte aggregates were positively associated with plasma levels of fibrinogen (P < 0.01), or serum high-sensitive C-reactive protein (P < 0.01). Moreover, LA had highly significant associations with brachial-ankle pulse wave velocity (P < 0.001) and IMT (P < 0.001). In conclusion, we demonstrated hemorheologically that monocyte-platelet conjugates play an important role in aortic stiffness and IMT in HD patients.