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Plasma Levels of Platelet Factor 4 Measured by Radioimmunoassay
Author(s) -
Chesterman C. N.,
McGready Jennifer R.,
Doyle D. J.,
Morgan F. J.
Publication year - 1978
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1978.tb05819.x
Subject(s) - platelet factor 4 , radioimmunoassay , platelet , medicine , in vivo , platelet activation , endocrinology , biology , microbiology and biotechnology
S ummary . A radioimmunoassay has been developed to measure platelet factor 4 (PF 4 ) in biological fluids both in vitro and in vivo . The assay has been shown to be highly specific for PF 4 and has a sensitivity of 0.08 ng/assay tube and 1.6 ng/ml of plasma. The preparation of plasma for the measurement of in vivo levels of PF 4 requires the use of an anticoagulant containing EDTA, theophylline and prostaglandin E 1 , the immediate cooling of the blood and high speed or prolonged centrifugation to reduce platelet contamination. Plasma levels of PF 4 are normally between 4 and 24 ng/ml with a median of 7.4 ng/ml. Plasma PF 4 levels are markedly increased during cardiopulmonary bypass surgery with shortened 51 Cr‐labelled platelet survival times and during arterial thrombosis. However, despite similarly shortened platelet survival times, the level of PF 4 is normal in immune thrombocytopenia. Elevations of plasma PF 4 levels are found following surgery, acute myocardial infarction and frequently during acute infections and in inflammatory states. On the contrary, normal levels are usual in disseminated malignancy, in severe hepatic and renal disease and in chronic arterial disease. The measurement of PF 4 is a useful addition to the study of platelet pathophysiology. It is apparent, however, that raised levels are by no means specific for thromboembolic disease and similarly platelet destruction is not invariably associated with abnormally increased plasma PF 4 levels.