EFFECT OF DIFFERENT DIALYSIS MEMBRANES ON PLATELET-FUNCTION - A TOOL FOR BIOCOMPATIBILITY EVALUATION

Intradialytic coagulative and platelet activation, one of the main con sequences of blood-membrane contact, was studied in a group of 5 RDT p atients with a comparative evaluation of 3 different dialytic membrane s: Cuprophan (CU), Polysulfone (PS) and Cellulose Triacetate (CT). Eac h patient underwent 5 consecutive dialysis sessions with the above men tioned membranes. Intradialytic platelet activation was studied throug h a morpho-functional evaluation between the mean platelet volume (MPV ) and Serotonin (S), beta-Thromboglobulin (beta-TG) and Platelet Facto r 4 (PF4) serum levels. These determinations were made before HD (time 0) and after 30', 120' and 240'. We also checked the intradialytic st atus of thrombogenesis and fibrinolysis determining aPTT, thrombin tim e fibrinogen, antithrombin III (AT III), alpha-2 antiplasmin and plasm inogen, af the same time intervals. Ail membranes tested (CU, PS, CT) caused appreciable intradialytic platelet activation, above all after 15' and at the end of dialysis sessions, more marked for CU than PS or CT in particular MPV showed a decrease throughout the session (-5% at 30' and -9% at 240') while S, beta TG and PF4 peripheral blood levels showed a significant increase at the same intervals with CU membrane. Lastly coagulative and fibrinolytic parameters showed no significant differences among any of the membranes tested.