Effects of rHuEPO treatment on red blood cell osmotic resistance.

Red blood cell osmotic resistance (RBCOR) is defined as resistance to osmotic changes in cell integrity after their exposure to hypotonic saline solution. The investigation examined the effect of rHuEPO on RBCOR in hemodialysed patients. The study included 58 patients aged 49 +/- 14 years, treated by hemodialysis for 59 +/- 43 months on average. Half of the patients received rHuEPO for anemia correction. RBCOR was determined in all patients as 3 values: hemolysis start point (HSP), hemolysis end point (HEP) and middle osmotic resistance (MOR). The patients underwent laboratory checkup for parameters characteristically changed in the uremic syndrome. In the control group of healthy subjects (n = 16) RBCOR was only determined. No differences were found in the average values of HSP, HEP and MOR between the rHuEPO treated group of patinets and the untreated group. Compared to healthy individuals, the hemodialysed patients displayed significantly higher values of HSP, HEP and MOR. The only one significant correlation of RBCOR and routine laboratory features was found between MOR and predialytic serum concentrations of calcium (r = 0.28, p < 0.05) and hydrogen ions (r = 0.37, p < 0.05). Our results suggest that the administration of rHuEPO does not affect RBCOR in hemodialysed patients, that RBCOR is not always reduced in this population and that it correlates with a small number of laboratory parameters characteristic for the uremic syndrome.