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In Vitro Spontaneous Thrombin Generation in Human Factor‐IX Concentrates
Author(s) -
Sas Geza,
Owens Rosemary E.,
Smith James K.,
Middleton Sarah,
Cash John D.
Publication year - 1975
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.1365-2141.1975.tb00828.x
Subject(s) - thrombin , thrombogenicity , fibrinogen , in vitro , factor ix , chemistry , antithrombin , clotting factor , factor xiii , in vivo , clotting time , incubation period , factor x , immunology , chromatography , biochemistry , incubation , medicine , platelet , biology , heparin , microbiology and biotechnology
S ummary . A series of in vitro studies designed to ascertain the potential in vivo thrombogenicity of human factor IX‐containing concentrates is described. Using concentrates obtained from several different Centres the fibrinogen clotting time with some preparations was less than 6 h and/or the recalcification time of normal plasma was shortened. In some preparations, however, the plasma recalcification time was lengthened. Further studies revealed that all diluted factor‐IX concentrates generated thrombin after recalcification, and that the rate of thrombin generation appeared to be characteristic of a particular preparation. This characteristic has been designated the TGt 50 , which is the incubation period in minutes, after recalcification, required to obtain a 50 s clotting time of a fibrinogen substrate. The TGt 50 was found to correlate most strongly with recalcification time of celite exhausted plasma ( P < 0.001), but no correlation was observed between it and the immunological antithrombin III or factor‐VIII antigen levels. Evidence is presented which suggests that the thrombin generation test and recalcification time of celite exhausted plasma may represent suitable in vitro quality control assays for factor‐IX concentrates.