fibrinopeptide-a and Uremia

In the present study, uremic patients on chronic maintenance hemodialysis were treated with recombinant erythropoietin. Before and after 20 weeks of treatment, platelet adhesion and aggregation were studied with perfusions over a sprayed collagen surface and over matrix of cultured endothelial cells with high tissue factor activity. The influence of the erythropoietin induced raise in hematocrit on platelet transport and adhesion was excluded by performing the perfusions at a standard red blood cell concentration. The present study clearly demonstrates that erythropoietin treatment improves platelet adhesion and aggregation in addition to and independent of its effect on the hematocrit. Studies with control platelets resuspended in plasma of untreated patients showed that a uremic plasma factor reduced adhesion and thrombin- and collagen-dependent aggregation. Patient platelets resuspended in control plasma showed no defects. After erythropoietin treatment, the plasma-induced inhibition of adhesion and aggregation had almost completely disappeared from patient plasma. The beneficial effect of the erythropoietin treatment on uremic hemostasis is therefore twofold. The increase of the red blood cell mass improves transport of platelets, and thus adhesion to the vessel wall. The intrinsic defect due to the presence of an inhibitory toxin in uremic plasma is, in large part, corrected. Improved neutralization of uremic toxins by red blood cells or less production of toxins by better oxygenated tissue might play a role in the observed phenomena.

Topics: Adult; Aged; Anemia; Cells, Cultured; Collagen; Erythropoietin; Female; Fibrinopeptide A; Heparin, Low-Molecular-Weight; Humans; Male; Middle Aged; Perfusion; Platelet Adhesiveness; Platelet Aggregation; Recombinant Proteins; Uremia

The coagulative system has an important role on haemodialysis and on atherosclerosis genesis; in particular the platelets are key elements of the coagulation and of atherosclerosis phenomena. Alterations of the coagulative system and increase risk of developing atherosclerosis are reported in the aging. We in this paper, report the results obtained studying the influence of the interaction between the elderly and dyslipidemia on the coagulative system in haemodialyzed patients. The obtained data showed that the hypertriglyceridaemia in interaction with the elderly accelerates and increases platelet aggregation after stimulation by ADP, Epinephrine and Collagen. So, it is important to consider hypertriglyceridaemia and age as thrombogenic factors and atherosclerosis accelerating factors in haemodialyzed patients.

Topics: Adenosine Diphosphate; Age Factors; Aged; Arteriosclerosis; beta-Thromboglobulin; Blood Coagulation Disorders; Collagen; Epinephrine; Fibrinopeptide A; Humans; Hypertriglyceridemia; Middle Aged; Platelet Aggregation; Renal Dialysis; Thrombin; Uremia

During 18 hemodialyses of patients with chronic uremia a low molecular weight heparin fraction (mean MW 5000 d) was used as an anticoagulant without complications. For comparison conventional heparin was used during 18 dialyses in the same patients. Equipotent doses, with regard to Xa inhibition of heparin and the 5000d fraction, suppressed FPA generation (fibrin formation) equally. The APT-times were less prolonged by the 5000d fraction. When the 5000d fraction was doubled in relation to conventional heparin with regard to Xa inhibition, the suppression of FPA generation was more effective than with conventional heparin, without more pronounced APTT prolongations. In conclusion this heparin fraction was found to be useful as an anticoagulant during hemodialysis and to give less pronounced APTT prolongation than conventional heparin.

Topics: Adult; Aged; Chronic Disease; Factor X; Factor Xa; Female; Fibrinopeptide A; Heparin; Humans; Male; Middle Aged; Molecular Weight; Partial Thromboplastin Time; Renal Dialysis; Uremia

Topics: Blood Preservation; Blood Specimen Collection; Burns; Disseminated Intravascular Coagulation; Fibrinogen; Fibrinopeptide A; Freezing; Humans; Immune Sera; Neoplasms; Plasma; Radioimmunoassay; Streptokinase; Thrombin; Thrombophlebitis; Uremia; Venous Pressure; Wounds and Injuries