Propyl gallate-induced platelet aggregation in patients with end-stage renal disease: the influence of the haemodialysis procedure.

BACKGROUND Platelet dysfunction is a well-established disturbance in haemodialysis (HD) patients. Propyl gallate is a synthetic platelet activator with the property to stimulate platelet aggregation. The aim of the present study was to evaluate the influence of a single haemodialysis session on propyl gallate-induced platelet aggregation. METHODS Thirty-nine HD patients were enrolled in the study and 20 healthy volunteers were studied as controls. Cellulose diacetate (CD) dialysers were used in 20 patients and polysulphone dialysers in 19. HD was performed via an A-V fistula in 27 patients and via an i.v. catheter in 12. Erythropoietin was administered in 37 patients (epoietin-alpha in 24 and darbepoietin in 13). Thirty-four were receiving the low-molecular-weight heparin tinzaparin. Propyl gallate slide aggregometry was used for evaluating platelet aggregation. RESULTS In HD patients, platelet aggregation was impaired before as well as after the HD session. No effect of the HD procedure, type of vascular access, adequacy of HD or type of erythropoietin on the propyl gallate-induced platelet aggregation was detected. Platelet aggregation was higher when CD dialyser was used. A negative correlation between the time needed for platelet aggregation to occur and tinzaparin dose was found. CONCLUSION Propyl gallate-induced platelet aggregation in HD patients is impaired. Platelet aggregation was higher in patients dialysed with CD membrane than in those dialysed with polysulphone membrane. The higher the dose of tinzaparin, the higher the platelet aggregation. The clinical significance of the above results needs further evaluation.