Observations on the Heparin Neutralizing Activity of Outdated Platelet Concentrates

Summary

A crude extract of outdated, washed, frozen and thawed, platelet concentrates was prepared and optimally diluted for use in the A. P. T. T. test as a source of platelet phospholipid (P. F. 3). The extract contained, in addition to P.F. 3, active heparin neutralizing activity (P. F. 4), which was able to neutralize plasma heparin up to a concentration of approximately 0.8 units/ml plasma. Although these observations are of a preliminary nature, it is felt that the extract can be used to follow the “intrinsic” coagulability of plasma samples from patients receiving therapeutic heparin. Utilizing the A. P. T. T. test system, the determination of coagulability and the neturalization of heparin result from the use of this extract in a single test.

Keywords

Platelet factor 4 - Heparin neutralizing activity - Activated partial thromboplastin time (A.P.T.T.)

• References

• 1 Conley CL, Hartmann RC, Lalley JS. The relationships of heparin activity to platelet concentration. Proc Soc Exp Biol Med 1948; 69: 284-286
• 2 Creveld vanS, Paulssen MM. Significance of clotting factors in blood platelets in normal and pathological conditions. Lancet 1951; 2: 242-244
• 3 Jurgens R. Funktion der Thrombozyten bei Blutung und Thrombose. Wiener Klin Wachr 1954; 66: 8504
• 4 Kubisz P, Levy-Toledano S, Cronberg S, Pinkhas J, Caen J. Effect of phentolamine, an alpha receptor blocking agent, on epinephrine, ADP and collagen induced platelet factor 4 release and platelet aggregation. Rev Eur Etud Clin Biol 1970; 15: 429-432
• 5 Niewiarowski S, Lipinski B, Farbiszewski R, Poplawski A. The release of platelet factor 4 during platelet aggregation and the possible significance of this reaction in haemostasis. Experientia 1968; 24: 343-344
• 6 Donati MB, Palester-Chlebowczyk M, de Gaetano G, Verlen J. Platelet factor 4: properties and clinical significance. In: Platelet Function and Thrombosis. Mannucci PM, Gorini S. (eds) Plenum Press; New York: 1972. pp 173-189
• 7 Yin ET, Wessler S, Butler J. Plasma heparin: a unique, practical submicrogram sensitive assay. J Lab Clin Med 1973; 81: 298-310
• 8 Jacques LB, Walters ET. Identity and origin of anticoagulant of anaphylactic shock in dog. J Physiol 1941; 99: 454-466
• 9 Preston FW, Parker RP. New antiheparin agent: polybrene; effect in peptone shock and in experimental radiation injury. Arch Surg 1953; 66: 545-551
• 10 Hirsh J, Genton E, Hull R. Venous Thromboembolism. Grune and Stratton; New York: 1981. p 166