Spontaneous Platelet Aggregation in Cerebrovascular Disease

Summary

50 patients from a group of 130 patients with transient ischaemic attacks or cerebral infarction were found to demonstrate in vitro spontaneous platelet aggregation (SPA) while 80 normal subjects tested never showed this phenomenon.

The following additional findings point towards a possible platelet abnormality:

1. Platelets from 10 patients with SPA when isolated and resuspended in normal plasma still demonstrated SPA while isolated normal platelets resuspended in patient’s plasma did not.

2. Platelets demonstrating SPA showed an increased aggregation tendency upon incubation with ADP while normal platelets developed the expected refractory state.

SPA was found to be dependant upon the presence of divalent cations and could further be inhibited by phentolamine and adenosine. Aspirin effectively abolished SPA in 50 patients and relieved the clinical symptoms of patients with recurrent complaints of transient blindness and paraesthesia.

• References

• 1 Barbui T, Battista R, Dini E. 1973; Spontaneous platelet aggregation in myeloproliferative disorders. Acta Haematologica 50: 25
• 2 Born GVR. 1962; Aggregation of blood platelets by adenosine diphosphate and its reversal. Nature 194: 927
• 3 Feissly R, Ludin H. 1949; Action of cocaine on blood platelets. Helvetia Physiologica Pharmacologica Acta 7: 69
• 4 Genton E, Gent M, Hirsh J, Harker LA. 1975; Platelet-inhibiting drugs in the prevention of clinical thrombotic disease. New England Journal of Medicine 293 1174 1236-1296
• 5 George JN, Lewis PC, Sears DA. 1976; Studies on platelet plasma membranes. II. Characterization of surface proteins of rabbit platelets in vitro and during circulation in vivo using diazotized (¹²⁵I)-diiodosulphanilic acid as a label. Journal of Laboratory and Clinical Medicine 88: 247
• 6 Kalendovsky Z, Austin J, Steele P. 1975; Increased platelet aggregability in young patients with stroke. diagnosis and therapy. Archives Neurology 32: 13
• 7 Murphy EA, Frances ME. 1971; The estimation of blood platelet survival. II. The multiple hit theory. Thrombosis et Diathesis Haemorrhagica 25: 53
• 8 O'Brien JR. 1962; Platelet aggregation. Some effects of the adenosine phosphate, thrombin and cocaine upon platelet adhesiveness. Journal Clinical Pathology 15: 446
• 9 O'Malley BC, Ward JD, Timperley WR, Porter NR, Preston FE. 1975; Platelet abnormalities in diabetic peripheral neuropathy. Lancet II: 1274
• 10 Preston FE, Emmanuel IG, Winfield DA, Malia RG. 1974; Essential thrombocythaemia and peripheral gangrene. British Medical Journal 3: 548
• 11 Preston FE. 1976. Circulating platelet aggregates in transient cerebral ischaemia. Combined Meeting of the Nederlandse Vereniging voor Hematologie and the British Society for Haematology. 54th General Meeting, Amsterdam The Netherlands
• 12 Vreeken J, Van Aken WG. 1971; Spontaneous aggregation of blood platelets as a cause of idiopathic thrombosis and recurrent painful toes and fingers. Lancet II: 1394
• 13 Walsh PN. 1972; Albumin density gradient separation and washing of platelets and the study of platelet coagulant activities. British Journal of Haematology 22: 205
• 14 Walsh PN, Pareti FI, Corbett JJ. 1976; Platelet coagulation and serum lipids in transient cerebral ischaemia. New England Journal of Medicine 295: 854
• 15 Wu KK, Hoak JC. 1976; Spontaneous platelet aggregation in arterial insufficiency. Mechanisms and applications. Thrombosis and Haemostasis 35: 702
• 16 Ziegler DK, Hassanein RS. 1973; Prognosis in patients with transient ischaemic attacks. Stroke 4: 666