ANEMIA, CHRONIC-RENAL-FAILURE AND ERYTHROPOIETIN

We have studied 249 patients with several degrees of kidney disease in order to assess the relationship between anaemic status serum level of erythropoietin and renal function. None of them were enrolled as a control group in order to obtain normal values. Patients were studied globally and then separately in five diagnostic categories: cystic, glomerular, interstitial, vascular and systemic, according to the aetiology of their disease. The study shows a good correlation between haemoglobin and creatinine clearance logarithms. The most severe degree of anaemic corresponds to the systemic aetiology; the glomerular and interstitial groups are at an intermediate situation and finally, vascular and cystic categories show the highest haemoglobin values. The group of patients with glomerular and vascular disease and both normal or diminished renal function show significantly higher serum erythropoietin level than the healthy subjects. The rest of diseases only show this fact when creatinine clearance is diminished. Erythropoietin does not correlate with renal function and shows a weak correlation with haemoglobin (r=-0.22, p < 0.001). The good correlation that exist between anaemic status and renal function and the limited or absent correlation between those parameters with the serum level of erythropoietin lead us hiperparatiroidism, toxic substances wich decrease red blood cells survival, deficiency of some factors... etc must have an influence on the appearing of the anaemic syndrome in the patient with chronic renal insufficiency. There is not an absolute deficiency of folic acid or vitamin B12 in anaemia associated with chronic renal failure.