Leukopenia and rheological anomalies in leukocytes during hemodialysis in patients with chronic renal failure.

Abstract

In order to clarify the relation between leukopenia during hemodialysis and leukocyte adhesiveness, the number of circulating leukocytes, their filterability through 5 micron diameter pores, and the concentration of neutrophil elastase in plasma were measured in peripheral blood collected at the beginning of hemodialysis (dialyzer, cuprophane membrane), 15 min into dialysis, and end of dialysis (duration of dialysis, 180 min) in 15 patients with chronic renal failure. Leukopenia was most marked at 15 min in all patients. In accordance with the change in number of circulating leukocytes, the filtration time of the leukocytes, as determined by a modification of the Nuclepore filtration method (filtered blood volume 0.5 ml, leukocyte count 2,500 microliters, suction pressure 10 cm H2O temperature 37 degrees C) was significantly longer at 15 min versus the beginning and end of the dialysis (p < 0.005 and p < 0.025, respectively). Addition of the chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (FMLP; 20 nM), to the suspensions immediately increased the leukocyte filtration time. Such FMLP-induced increases were significantly greater at 15 min versus the beginning of dialysis (p < 0.05). This heightened sensitivity of cells to FMLP appeared to persist until the end of dialysis (p < 0.05 versus the beginning). Plasma levels of neutrophil elastase were highest at the end of dialysis versus those at the beginning and after 15 min (both p < 0.005). Results suggest that the changes in filterability of leukocytes may be related to decreases in their number in the circulation. Neutrophil elastase appeared to accumulate in plasma so that its maximal value at the end of dialysis would reflect the preceding changes in leukocyte rheology.