Reactive oxygen species production by monocytes and polymorphonuclear leukocytes during dialysis.

Intradialytic production of reactive oxygen species (ROS) by monocytes and polymorphonuclear leukocytes (PMNL) was examined separately in six hemodialysis patients. Samples obtained 15 minutes after initiation of dialysis with new cuprophane membranes demonstrated significantly increased (P less than 0.05) ROS production in both cell populations as measured by the fluorescence of a specific intracellular marker (2',7'-dichlorofluorescein diacetate [DCFH-DA]) assayed by flow cytometry. Granulocytes harvested during dialysis also showed decreased responsiveness to exogenous C5a and F-Met-Leu-Phe (FMLP) at 15, 30, and 60 minutes after initiation of dialysis (P less than 0.05). Our data suggest that hemodialysis with cuprophane membrane is associated with monocyte and PMNL activation as shown by production of ROS coincident with peak activation of the complement cascade; these granulocytes become refractory to further stimulation with C5a and FMLP during dialysis.