Acquired bleeding disorders
Acute phase reaction

Topic Completed: 1 September 2010

Revised: 4 January 2019, last major update September 2010

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Acute phase reaction [title] coagulation

Kendall Crookston, M.D., Ph.D.
Lizabeth S. Rosenbaum, M.D.
Page views in 2019: 187
Page views in 2020 to date: 56
Cite this page: Crookston K., Rosenbaum L., Gober-Wilcox J. Acute phase reaction. website. Accessed August 3rd, 2020.
Definition / general
  • Many serum proteins become elevated due to illness, injury, inflammation or stress
    • Also pregnancy
  • Elevated levels return to normal after condition resolves
  • Also called positive acute phase proteins
  • In response to injury, neutrophils and macrophages secrete IL-1, IL-6, IL-8 and TNF-a into the bloodstream
  • Production of other proteins is reduced ("negative" acute phase reactants)
  • Associated with increase in fibrinogen, factor VIII, vWF (up to 3x normal levels) and PAI-1 (up to 50x)
  • Associated with decrease in PTT, decrease in protein S (due to binding to increased C4b)
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