Hemodialysis membrane-induced activation of phagocyte oxidative metabolism detected in vivo and in vitro within microamounts of whole blood.

The production of reactive oxygen species by phagocytes from uremic patients undergoing hemodialysis was monitored by chemiluminescence (CL) within microamounts of whole blood or isolated polymorphonuclear (PMN) cells, and compared on the basis of the dialysis membrane, cuprophane (CUP) or polyacrilonitrile (PAN). Compared to control subjects, resting and stimulated CL (with latex, zymosan, phorbol myristate acetate (PMA) but not formyl-methionyl-leucyl-phenylalanine (FMLP) were decreased in 10(-2) diluted blood sampled before dialysis. After 15 min of dialysis (ti), resting whole blood (10(-1) and 10(-2) diluted) CL increased sharply in patients dialyzed with the CUP but not the PAN membrane, while it returned to its predialysis level at the end of the session. This sharp resting CL increase found in whole blood at ti was not observed in isolated PMN cells except when tested with ti plasma from CUP dialyzed patients, suggesting that it was mediated via activated plasma compounds. In vitro treatment of normal blood, plasma, and isolated PMN cells with CUP membrane fragments reproduced this in vivo dialysis-induced activation of phagocyte oxidative metabolism strikingly and demonstrated additionally the requirement of complement for its induction. We propose this model as an effective means of evaluating dialysis membrane biocompatibility.