EXISTENCE OF A PLATELET-ADHESION DEFECT IN PATIENTS WITH CIRRHOSIS INDEPENDENT OF HEMATOCRIT - STUDIES UNDER FLOW CONDITIONS

A defect in hemostasis has been repeatedly reported in patients with c irrhosis, However, the nature of this defect has not been fully charac terized. We explored adhesive and cohesive functions of platelets from cirrhotic patients at different stages of disease development, The re sponse of platelets to standard activating agents was tested by aggreg ometric procedures. The interaction of platelets with subendothelial c omponents was explored in a perfusion system in which blood was expose d (shea rate, 800/s; 10 minutes) to denuded segments of rabbit aorta P latelet interactions in these perfusions were analyzed morphometricall y, Results were always compared with those obtained in similar studies using blood obtained from healthy subjects, Aggregation studies showe d abnormal responses for single or several agonists, Abnormalities in aggregation were more evident in patients with severe disease (Child-P ugh class C), although they occasionally were abnormal for single agon ists (ADP or U46619) in patients with less severe disease (Child-Pugh classes A or B). All the patient classes showed impaired platelet-sube ndothelial interactions (P <.01 vs. healthy subjects) that were not ju stified by the relative thrombocytopenia present in the more severely affected patients. Experimental increases in hematocrit in patients at stages B and C did not improve platelet-subendothelial interactions, Platelets from cirrhotic patients interact defectively with subendothe lial components under flow conditions, The adhesion defect is more evi dent and consistent than the aggregation defects and may already be pr esent in patients with mild Liver failure, This adhesion defect may co ntribute to the defective hemostasis observed in cirrhotic patients.