Changes in Red Blood Cells Membrane Protein Composition during Hemodialysis Procedure

Abstract

Our aim was to evaluate the influence of the hemodialysis (HD) procedure in red blood cells (RBC) membrane protein composition. We evaluated hematological data (RBC count, hemoglobin concentration, and hematimetric indices) and RBC membrane protein composition (linear and exponential gradient polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate [SDS-PAGE] followed by densitometry analysis of RBC membrane proteins) before and immediately after the HD procedure in 20 patients (10 responders and 10 non-responders to recombinant human erythropoietin therapy [rhEPO]) and 26 healthy controls. Before HD, patients presented anaemia and significant changes in membrane protein composition, namely, a statistically significant reduction in spectrin associated with a significant increase in bands 6, as well as an altered membrane protein interaction (protein 4.1/spectrin, protein 4.1/band 3, protein 4.2/band 3 and spectrin/band 3). After HD, we found that patients showed a statistically significant increase in RBC count and hemoglobin, a further and statistically significant decrease in spectrin, an increase in band 3, and an altered spectrin/band 3 ratio. When comparing responders and non-responders patients after HD, we found that the non-responders presented a trend to a higher reduction in spectrin. Our data suggest that HD procedure seems to contribute to a reduction in spectrin, which is normally associated with a reduction in RBC deformability, being that reduction in spectrin is higher in non-responder patients.

Neutrophil Activation and Erythrocyte Membrane Protein Composition in Stage 5 Chronic Kidney Disease Patients

“…This increase in circulating erythrocytes, has been associated (Dasselaar, 2007) translocation of erythrocytes from the splanchnic circulation (and possibly from the splenic circulation) in order to compensate the hypovolemic stress during dialysis ultrafiltration. We also found, after haemodialysis, an increase in mean cell hemoglobin concentration and a decrease in mean cell volume that could be related to erythrocyte membrane protein loss during the hemodialysis procedure (Costa, 2008b). Markers of neutrophil activation were also found to be increased after haemodialysis.…”

“…Significant increases in protein bands 6 and 7 were also observed, which may further reflect an altered membrane protein interaction and destabilization of membrane structure. This membrane destabilization was further strengthened by the significant changes observed for spectrin/band 3 ratio (Costa, 2008b;Costa, 2008d). These membrane protein changes may be due to a higher erythrocyte metabolic stress and/or to changes resulting from the haemodialysis procedure per se.…”

“…The haemodialysis procedure, itself, seems to lead to neutrophil activation (Costa, 2008a). By evaluating CKD patients before and after haemodialysis procedure (Costa, 2008b), we found a higher haemoglobin concentration and erythrocyte count after haemodialysis (Table 2). This increase in circulating erythrocytes, has been associated (Dasselaar, 2007) translocation of erythrocytes from the splanchnic circulation (and possibly from the splenic circulation) in order to compensate the hypovolemic stress during dialysis ultrafiltration.…”

“…Actually, no differences were found after haemodialysis, in band 3 profile. Some changes in erythrocyte membrane protein composition of stage 5 CKD patients using high-flux polysulfone FX-class dialysers of Fresenius, were also observed (Costa, 2008b;Costa, 2008d). A decrease in spectrin was the most significant change (table 4).…”

Does the extracorporeal circulation worsen anemia in hemodialysis patients? Investigation with advanced microscopes of red blood cells drawn at the beginning and end of dialysis

“…The possible mechanisms motivating and/or promoting the decreased lifespan of RBCs can be categorized as extrinsic (extracorporeal circuit) or intrinsic (uremic milieu). The extrinsic mechanisms relate to the extracorporeal circulation of the HD patient's blood during dialysis, since this can induce mechanical stress, 8,9 biochemical activation, 10,11 and membrane compositional modifications [12][13][14][15] to the RBCs. Intrinsic mechanisms refer to the interference of the biochemically crowded landscape of the RBC membranes (receptors, transport channels, etc) with the complex environment of uremic toxins.…”