Platelet Coagulant Activities in Metrizamide Gradient Platelets : Application to Bernard-Soulier and Thrombotic Disorders

A new technique for platelet isolation from five ml of total blood on metrizamide gradients has been applied to the study of platelet coagulant activities.” Assay methods have been described : contact product forming activity (CPFA), collagen induced coagulant activity (CICA) and platelet factor three (PF3) have been measured in the metrizamide gradient platelets (MGP) and found similar to that of platelets in platelet richplasma (PRP).

Platelet coagulant activities of the MGP have been measured in patients with hemorragie tendencies like Bernard-Soulier (B-S) patients or those with thrombotic tendencies including diabetics with or without vascular complications or patients with transient ischemic attacks (TIA). CICA was not found in. all the 3 patients with B-S syndrome. 3 of the 10 diabetics showed an increased CPFA activity while 5 showed an increased CICA activity contrasting with the normal activities found in diabetics without vascular complications ; PF3 activity is increased in the two groups of diabetics. 3 patients of the 7 with TIA had an increased CPFA as well CICA.

The results suggest that these activities may play some role in diabetics with vascular complications and in some cases with TIA.