PROLIFERATION OF CIRCULATING HEMATOPOIETIC STEM CELLS IN CHRONIC RENAL FAILURE

Background. The cause of anemia in chronic renal failure seems to be multifactorial. The aim of our investigation was to verify the hypothesis that the causes of anemia are at a higher stem cell level. Therefore, beside peripheral blood BFU E which require erythropoietin, we cultivated peripheral blood stem cells which do not require it – CFU GM and CFU GEMM. Patients and methods. Peripheral blood BFU E, CFU GM and CFU GEMM were studied in 65 uremic patients who were placed on maintenance hemodialysis three times weekly. All were anemic. In regard to creatinine concentration they were divided into Group 1 with creatinine concentration < 900 µmol/L (24 pts) and Group 2 with creatinine concentration > 900 µmol/L (41 pts). Hematopoietic colony-forming cells from blood were assayed in a methylcellulose culture with growth factor addition. Results. The growth of colonies BFU E and CFU GM was significant inhibited in whole group of patients, growth of CFU GEMM was significantly inhibited in the Group 2. A positive correlation of the CFU GM and BFU E, CFU GEMM and BFU E and CFU GM and CFU GEMM colonies was found in the whole group of patients. There was a negative correlation between the growth of the CFU GEMM, CFU GM and BFU E colonies and the urea concentration in the entire group of patients. In Group 1 a negative correlation was found between the growth of the BFU E and CFU GM colonies and creatinine concentration. In the Group 2 a negative correlation between growth of the BFU E and CFU GM and urea concentration was found. Conclusions. According to our study, erythropoetin concentration, although normal, is still too low with regard to the grade of anemia. In patients the number of stem cell colonies was decreased significantly, correlating with the severity of uremia. This confirms the hypothesis that disturbed hematopoiesis in uremia is affected by additional factors and that their influence in uremia is permanent.