[Clinical study of biocompatibility of dialysis membranes made from non-modified and modified cellulose]

Basic biocompatibility parameters of dialysis membranes made of non-substituted regenerated cellulose (NRC) and cellulose membranes with hydroxyl groups substituted, to a higher (H) or lower (L) degree, by dl-ethyl-amino-ethyl groups (DEAE), or by acetate (CA) were investigated in a 16-week clinical study, involving 10 long-term haemodialysis patients. In the 15th minute of dialysis, the decrease in blood leukocyte count, while using NRC (0.24 +/- 0.03 of baseline value, arithmetic mean +/- SEM) was deeper compared with that seen in DEAE-L (0.88 +/- 0.10, p < 0.001), in DEAE-H (0.79 +/- 0.10, p < 0.01), and in CA (0.73 +/- 0.05. p < 0.05). In the 15th minute of the procedure, C5a concentrations, reflecting complement activation, were higher in NRC (4.4 +/- 0.51 micrograms/L) than in DEAE-L (1.41 +/- 0.22, p < 0.001), in DEAE-H (1.68 +/- 0.47, p < 0.01), and in CA (1.68 +/- 0.22, p < 0.01). Activated clotting times were, in the 10th minute of the procedure, significantly longer in NRC (2.94 +/- 0.37 of baseline value) than in DEAE-H (1.74 +/- 0.10, p < 0.05) and, by the end of dialysis, the difference between these membranes (NRC: 1.47 +/- 0.21, DEAE-H: 0.85 +/- 0.08, p = 0.07) was close to the level of statistical significance. The authors conclude: 1. Substitution of the hydroxyl groups of regenerated cellulose reduces the decrease in leukocyte count and complement activation in the initial phase of haemodialysis. 2. At the same time, substitution by DEAE groups may raise thrombogenicity, as indicated by the shorter activated clotting times.(ABSTRACT TRUNCATED AT 250 WORDS)