Factor xiv

Factor XIV is an activator of factor XII. The HMWK ("high-molecular-weight kininogen") acts as a cofactor in the activation of factor XI. HMWK is cleaved by Kallikrein, which releases bradykinin. It forms complexes with prekallikrein and F-XI.

Factor XIV is an alpha-2 single-chain peptide globulin with a molecular weight of 110,000 D and consists of two identical subunits.
In addition to its coagulation-activating properties, factor XIV also intervenes in inflammatory processes and complement activation, acts anti-adhesively for the leukocytes and thus anti-inflammatory. In addition, F-XIV also has an antithrombotic effect by antagonizing the kallikrein-dependent formation of urokinase.

Factor XIV can be detected in the thrombocytes from which it is released during the activation process.
The plasma concentration is 70-90mg/l or 70-120%. In case of severe liver damage, the HMWK may be reduced. In the plasma, the HMWK forms a 1:1 complex with prekallikrein.

In 1975, Waldmann and his colleagues observed a coagulation defect in a 71-year-old man named Fitzgerald who had gone to her treatment for a gunshot wound. He was found to have an unusually long bleeding time. By adding a plasma that was purified of all previously known coagulation factors, a previously new factor could be described that intervenes in the activation of the intrinsic system and is referred to in the literature as "high-molecular-weight kininogen" (HMWK).

1. HA Neumann (2014) The coagulation system. ABW-Wissenschaftsverlag GmbH Berlin S. 69f.