Anemia is a serious problem in hemodialysis patients, the main cause of which is erythropoietin deficiency. After the discovery of recombinant human erythropoietin (rHuEpo) at the end of the last decade, the hematological profile of hemodialysis patients improved significantly but at considerable expense. The deformability of red blood cells (RBC) influences their microcirculation and tissue oxygen delivery along with their life span. We investigated the deformabilty of RBCs in 15 hemodialysis patients before and after three months on L-carnitine supplementation (30 mg/Kg body wt/dialysis session). We excluded from the study all patients who received blood transfusions three months before or during the study, patients who had hemorrhagic episodes, those with hyperparathyroidism or infections, and any who required surgical intervention during the study. The serum iron, folic acid and vitamin B-12 levels were kept normal during the duration of the study. The erythropoietin dose taken before the beginning of L-cartnitine supplementation was not changed. The deformability of RBCs before and after dialysis, prior to and following three months on L-carnitine was determined and compared to the deformability of RBCs from a control group. Hematocrit levels were measured before entry into the study and every month for three months. We found that the deformability of RBCs before the dialysis session was significantly greater than that found in the control group (t-test, p < 0.00001), and that there was a further increase after the end of the dialysis session. Three months following L-carnitine supplementation, we found a significant reduction of RBCs deformability (paired t-test, p < 0.004), and a significant increase in the hematocrit (ANOVA, p < 0.0001). We concluded that abnormalities in the deformability of RBCs improved after L-carnitine and that this was responsible for the increase in the hematocrit. This may allow a substantial reduction in rHuEpo dose.

Anemia is the main problem for patients suffering from end stage renal disease (ESRD). This study aimed to determine whether the index of rigidity (IR), that shows red blood cells (RBCs) deformability and the possible IR disturbances can provide an explanation about the cause of anemia, in patients undergoing maintenance hemodialysis (HD) or on peritoneal dialysis. The IR was determined in 39 hemodialyzed patients, who were already in dialysis for a period of time ranging from 16 to 120 months (mean+/-SD=41.8 +/-24.1) (Group A). Furthermore, the IR was measured in 32 patients on continuous ambulatory peritoneal dialysis (CAPD), who were in CAPD for a period of time ranging from 6 to 60 months (mean+/-SD = 10.7+/-9.9) (Group B). Finally, the IR was determined in 17 normal individuals (group C). The RBCs IR was measured twice in group A (before and after the end of a hemodialysis session) and once in groups B and C. The IR was determined by hemorrheometry (method of filtration), using special equipment. In group A the IR was increased in comparison to the control group (C) (17.9+/-6.2 vs. 10.2+/-1.8, p<0.0001). This increase was even higher in the measurement at the end of the hemodialysis session (paired t-test, p < 0.0001). The RBCs IR in CAPD patients was significantly lower than that of HD patients (12+/-3.8 vs. 17.9+/-6.2, p<0.0001) and was not statistically different from the control group (12+/-3.8 vs. 10.2+/-1.8, p=0.068). It is concluded from the study that: 1) in HD patients occur disturbances in the deformability of the RBCs, that are worsened by the hemodialysis session; 2) the index of rigidity of RBCs is significantly higher in the HD patients than in CAPD patients; 3) in patients on CAPD, the disturbance of deformability of the RBCs was less in comparison to the control group, which however does not reach the statistically significant levels.