To investigate the contribution of hemolysis to anemia of peritoneal dialysis patients, we measured serum haptoglobin (Hp) levels in 47 patients on peritoneal dialysis.
The 4 patients (8.5%) whose Hp values were below the measurement sensitivity level (<10mg/dl) were assigned the hemolytic group, while another 43 patients (91.5%) were assigned to the non-hemolytic group. Serum lactate dehydrogenase and reticulocyte counts were significantly higher in the hemolytic group than in the non-hemolytic group (540.0±132.8 vs. 405.5±105.0IU/l, p<0.05 and 28.7±6.6 vs. 18.0±9.0‰, p<0.05). Hemoglobin concentration was significantly lower in the hemolytic group than in the non-hemolytic group (8.73±0.78 vs. 9.83±1.00g/dl, p<0.05). Doses of recombinant human erythropoietin tended to be higher in the hemolytic group (33000±6000 units/month vs. 20230±12490 units/month, p=0.051). However, dialysis duration, serum creatinine, β₂-microglobulin, intact parathyroid hormone, weekly Kt/V and weekly Ccr were not significantly different between the two groups.
The results of this study suggest that hemolysis may be a frequent cause of resistance to recombinant human erythropoietin therapy in peritoneal dialysis patients with anemia.