Leukopenia, hypoxia, and complement function with different hemodialysis membranes

Abstract

Complement activation during exposure of plasma to cuprophan has been postulated to cause leukopenia and hypoxia in hemodialysis patients. To determine if hypoxia is related to leukopenia and if complement activation leads to a depletion of functional complement components, we dialyzed four patients three times sequentially against each of four types of membranes: cuprophan, regenerated cellulose, cellulose acetate, and polyacrilonitrile. Within 20 min there was a marked leukopenia with cuprophan from 5541 +/- 376 to 1216 +/- 94 (P less than 0.001) and with regenerated cellulose from 5541 +/- 411 to 1533 +/- 203 (P less than 0.001). With cellulose acetate, the change from 5558 +/- 400 to 3783 +/- 341 (P less than 0.001) was less dramatic, and with polyacrilonitrile the fall from 5591 +/- 381 to 464 +/- 401 (P less than 0.02) was minimal. After 2 and 4 hours of dialysis, a rebound leukocytosis was seen with cuprophan, regenerated cellulose, and cellulose acetate, but not with polyacrilonitrile. Transient thrombocytopenia occurred with cuprophan and regenerated cellulose. In spite of the variable degree of leukopenia, all membranes induced a similar and significant hypoxia, which was progressive throughout dialysis, even during the rebound leukocytosis. After 4 hours, the mean PO2 ranged from 91 to 93 mm Hg with all membranes. Functional hemolytic titers of whole complement, C3, C5, and C4 were normal prior to hemodialysis and failed to decrease after 4 hours with any membrane. It is concluded that hemodialysis leukopenia is membrane-dependent and is not the cause of hypoxia. In addition, hemodialysis complement activation does not lead to functional complement depletion and is of no clinical significance.

Intradialytic Hypoxemia and Clinical Outcomes in Patients on Hemodialysis

“…Hypoxemia during hemodialysis has been recognized since the early days of dialysis (26)(27)(28)(29)(30)(31)(32). Over the years, several mechanistic explanations have been put forward.…”

Dialysis-Induced Hypoxemia

“…Jacob et al have found a similar degree of hypoxemia during dialysis with cuprophone, regenerated cellulose, cellulose acetate, and polyachrylonitrile membranes (25). However, the effects of these membranes on the leukocyte count were markedly different, with cuprophane producing the most and polyachrylonitrile the least changes.…”

Hemodialysis-AssociatedHypoxemia

“…Evi dence in support of this view can be summarized as fol lows: (1) whereas peripheral neutropenia peaks in the first 30 min of dialysis and resolves usually by the end of 1 h, hypoxemia persists for the duration of dialysis [1][2][3]; (2) peripheral neutropenia does not occur or is minimal when dialysis is performed with polyacrylonitryl or polysulfon membranes or with reused cellophane mem branes, yet hypoxemia does develop [2,3], and (3) when cellophane membranes are used to perform isolated ul trafiltration (i.e., in the absence of dialysate), peripheral neutropenia but not hypoxemia is observed [2,4], It should be mentioned, however, that a recent report [5] appears to reopen the question. In this study, patients were dialyzed using either cuprophane or polyacrylonitryl membranes, while the dialysis bath contained either bi carbonate (with CO2 bubbling) or acetate (without CO2 bubbling).…”