ACTION OF RHUEPO ON MECHANICAL MEMBRANE-PROPERTIES OF RED-BLOOD-CELLS IN CHILDREN WITH END-STAGE RENAL-DISEASE

By means of a micropipette aspiration technique mechanical membrane properties of RBC in ten uraemic children undergoing haemodialysis were compared to those of nine healthy children. In contrast to the healthy reference group (mu = 4.01 +/- 0.71-mu-N/m), the mean apparent elastic shear modulus of RBC membrane mu as a parameter of static deformability was significantly increased to 9.05 +/- 1.61-mu-N/m in children with chronic renal failure measured in the pre-study period. At the 7th week of the correction period of rHuEpo therapy, the haematocrit of treated patients is enhanced to a mean of 0.30 +/- 0.03, whereas mean mu is decreased to 5.41 +/- 0.63-mu-N/m. Within the maintenance period of rHuEpo treatment (30th week), the parameter mu did not show significant differences to the reference value 3.78 +/- 0.31-mu-N/m. Additionally, a significant increase in red cell mean corpuscular volume was obtained during rHuEpo therapy. Improved deformability of uraemic RBC induced by the rHuEpo therapy can only be explained by the assumption that in the course of this therapy an increasing number of cells with normalised viscoelastic properties have been formed by stimulated erythropoiesis.