In Vivo Platelet Release in Myeloproliferative Disorders

Summary

The in vivo platelet release reaction in 22 patients with myeloproliferative disorders has been studied by measuring plasma concentrations of the platelet release product β-throm-boglobulin (βTG). Mean βTG and mean βTG:whole blood platelet count ratio were significantly raised in the patient group taken as a whole compared to an age matched control group. No significant increases were observed in the plasma concentrations of thrombin and plasmin sensitive fibrinogen fragments fibrinopeptide A (FpA) and Bβ1-42. The patients were divided into those who had normal, increased or decreased responses to in vitro ADP-induced platelet aggregation. Mean βTG and the mean βTG:whole blood platelet count ratio were higher in the increased and decreased responders to ADP than in the normal aggregation group, but the differences in means were not statistically significant. Aspirin given to six patients at a dose sufficient to eliminate the secondary phase of ADP-induced platelet aggregation reduced mean βTG and the mean βTG : whole blood platelet count ratio but did not alter mean FpA and Bβ1-42. It is concluded that the enhanced platelet release reaction seen in myeloproliferative disorders is independent of plasma protease activity that arises when coagulation and fibrinolytic systems are activated.

Keywords

Myeloproliferative disorders - βTG - FpA - Bβ1-42

• References

• 1 Videbaek A. Polycythaemia vera: course and prognosis. Acta Med Scand 1950; 138: 179-187
• 2 Chievitz E, Thiede T. Complications and causes of death in polycythaemia vera. Acta Med Scand 1962; 172: 513-523
• 3 Wasserman LR, Gilbert HS. Complications of polycythaemia vera. Semin Haematol 1966; 3: 199-208
• 4 Wasserman LR, Bassen F. Polycythaemia. J Mt Sinai Hosp 1959; 26: 1-49
• 5 Dawson AA, Ogston D. The influence of the platelet count on the incidence of thrombotic and haemorrhagic complications in polycythaemia vera. Postgrad Med J 1970; 46: 76-78
• 6 Spaet TH, Gaynor E, Goldstein ML. Defective platelets in essential thrombocythaemia. Arch Intern Med 1969; 124: 135-141
• 7 Tangun Y. Platelet aggregation and platelet factor 3 activity in myeloproliferative disorders. Thrombos Diathes Haemorrh 1971; 25: 241-251
• 8 Berger S, Aledort LM, Gilbert HS, Hanson JP, Wasserman LR. Abnormalities of platelet function in patients with polycythaemia vera. Cancer Res 1973; 33: 2683-2687
• 9 Boughton BJ, Corgett WE, Ginsberg AD. Myeloproliferative disorders: a paradox of in vivo and in vitro platelet function. J Clin Pathol 1977; 30: 228-234
• 10 Boughton BJ, Allington MJ, King A. Platelet and plasma β thromboglobulin in myeloproliferative syndromes and secondary thrombocytosis. Br J Haematol 1978; 40: 125-132
• 11 Tytgat GN, Collen D, Vermylen J. Metabolism and distribution of fibrinogen. II. Fibrinogen turnover in polycythaemia, thrombocytosis, haemophilia A, congenital afibrinogenemia and during streptokinase therapy. Br J Haematol 1972; 22: 701-717
• 12 Christensen LE. The turnover of plasma fibrinogen. Acta Med Scand 1958; 162: 407-414
• 13 Blomback B, Carlson LA, Franzen S, Zetterquist E. ¹³¹I labelled fibrinogen in man. Studies in normal subjects, in congenital coagulation factor deficiency states, in liver cirrhosis, in polycythaemia vera and in epidermolysis bullosa. Acta Med Scand 1966; 1979: 557-574
• 14 Martinez J, Sharpiro SS, Holbum RR. Metabolism of human prothrombin and fibrinogen in patients with thrombocytosis secondary to myeloproliferative states. Blood 1973; 42: 35-46
• 15 Carvalho A, Ellman L. Activation of the coagulation system in polycythaemia vera. Blood 1976; 47: 669-678
• 16 Ludlam CA, Moore S, Bolton AE, Pepper DS, Cash JD. The release of a human platelet protein measured by a radioimmunoassay. Thromb Res 1975; 6: 543-548
• 17 Ludlam CA, Cash JD. Studies on the liberation of β thromboglobulin from human platelets in vitro. Br J Haematol 1976; 33: 239-247
• 18 Nossel HL, Yudelman I, Canfield RE, Butler VP, Spanondis K, Wilner GD, Qureshi GD. Measurement of fibrinopeptide A in human blood. J Clin Invest 1974; 54: 43-53
• 19 Nossel HL, Wasser J, Kaplan KL, La Gamma KS, Yudelman I, Canfield RE. Sequence of fibrinogen proteolysis and platelet release after intrauterine infusion of hyperonic saline. J Clin Invest 1979; 64: 1371-1378
• 20 Russel NH, Salman J, Keenan JP, Bellingham AJ. Platelet adenine nucleotides and arachidonic acid metabolism in the myeloproliferative disorders. Thromb Res 1981; 22: 389-397
• 21 Boneu B, Nouvel C, Sie P, Caranobe C, Combes D, Laurie G, Pris J, Bierme R. Platelets in myeloproliferative disorders. I. A comparative evaluation with certain platelet function tests. Scand J Haematol 1980; 25: 214-220