INCREASED RED-CELL 2,3-DIPHOSPHOGLYCERATE LEVELS IN HEMODIALYSIS-PATIENTS TREATED WITH ERYTHROPOIETIN

The efficacy of recombinant human erythropoietin (rHuEpo) for the trea tment of renal anaemia is well established. To assess the effect of rH uEpo treatment on physical performance we evaluated physical working c apacity, oxygen uptake and red cell 2,3-diphosphoglycerate (DPG) value s at rest and during and after exercise on a bicycle spiroergometer in eight chronically haemodialysed patients. Follow-up examination was c arried out after a mean of 14 weeks (range 9-19 weeks), when mean haem oglobin had increased from 7.8 to a stable value of 13.0 g/dl in respo nse to rHuEpo treatment (P < 0.001). Physical working capacity and oxy gen uptake at the anaerobic threshold (4 mmol/l blood lactate concentr ation) increased from 68 +/- 12 to 80 +/- 16 watts and 0.95 +/- 0.14 t o 1.10 +/- 0.20 l/min, respectively (P < 0.01). DPG, which determines oxygen affinity to haemoglobin in red cells, increased by 13% from 13. 7 +/- 1.5 to 15.5 +/- 2.2 mumol/g Hb (P < 0.05). With maximal exercise mean DPG values significantly decreased to a much lower level without rHuEpo treatment than after correction of anaemia. Therefore rHuEpo t reatment results both in better oxygen transport capacity and reduced intraerythrocytic oxygen affinity, which is followed by improved oxyge n delivery to tissues per unit of haemoglobin. These effects may expla in the improvement of exercise capacity observed in dialysis patients after rHuEpo treatment.