FLOW-CYTOMETRIC ANALYSIS OF MEPACRINE-LABELED PLATELETS IN PATIENTS WITH END-STAGE PENAL FAILURE

Platelet dysfunction and increased bleeding tendency has been the most consistently described haemostatic abnormality in patients with renal failure. Besides abnormalities in platelet membrane glycoproteins, a reduced amount of platelet-dense granule content has been demonstrated in patients with endstage renal failure (ESRD) indicating an acquired storage pool deficiency (SPD) present in uraemia. To study dense gran ules, platelets were labelled with mepacrine, a fluorescent probe whic h is specifically incorporated into dense bodies. MepaPlatelets of 13 patients with ESRD and of 11 healthy controls were studied. The result s showed that mepacrine-labelled platelets of patients with ESRD revea l a significantly (p < 0.05) reduced fluorescence compared to the cont rol group. This implies a reduced number or content of dense granules present in ESRD platelets. Thus, the current data indicate that ESRD i s associated with an acquired platelet SPD which may play an important role in the pathophysiology of uraemic bleeding tendency. Moreover, t he described FACS assay may be a useful and rapid method for screening patients with suspected acquired or inherited SPD.