Effect of regional citrate anticoagulation on leukopenia, complement activation, and expression of leukocyte surface molecules during hemodialysis with unmodified cellulose membranes

Background: Dialysis with complement-activating membranes is associated wit h leukopenia, which is related to an increased expression of adhesion molec ules on leukocytes. Citrate chelates calcium and has been claimed to attenu ate leukopenia. Methods: In this study, the effects of citrate anticoagulat ion on leukocyte and granulocyte counts, complement activation, and the exp ression of CD11b, CD11c, and CD45 on the surface of granulocytes were evalu ated during hemodialysis with unmodified cellulose membranes. Standard hepa rin was compared to citrate in three different schedules: citrate was infus ed to obtain a concentration of either 7 or 10 mmol/l blood. CaCl2 was admi nistered into the dialyzer outlet at 8.25 mmol Ca2+/h (citrate 10 mmol/l) o r at 11 mmol Ca2+/h (citrate 7 and 10 mmol/l) to restitute the calcium leve ls in the blood returning to the patient. Results: The use of citrate at a high concentration (10 mmol/l) was associated with a blunted upregulation o f CD11b, both at the inlet and at the outlet bloodline; for CD11c a reduced upregulation was observed on granulocytes harvested from the inlet bloodli ne. No effects of citrate were observed on leukopenia, granulocytopenia, or complement activation. A positive correlation between the decrease in syst emic ionized Ca2+ concentration and the increase in CD11b and CD11c express ion was found. Conclusion: Citrate/CaCl2 administration affects leukocyte a dhesion molecule expression in a dose-dependent way; however, no significan t effect could be demonstrated on leukopenia and complement activation. Cop yright (C) 2000 S. Karger AG, Basel.