What is the reference range for factor XI?

Updated: Feb 07, 2020
  • Author: Bishnu Prasad Devkota, MD, MHI, FRCS(Edin), FRCS(Glasg), FACP; Chief Editor: Eric B Staros, MD  more...
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The so-called contact factors include factor XI, factor XII, high-molecular-weight kininogen (HK), and prekallikrein (PK). Factor XI is synthesized in the liver and megakaryocytes and is an 80-kd zymogen precursor of a serine protease. It circulates in complex with the nonenzymatic cofactor HK [1] and has a mean plasma half-life of about 52 hours.

The reference range for factor XI is between 65% and 135% of normal values. [2]

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