Coagulation laboratory tests
Plasminogen assay

Author: Jeremy Parsons, M.D. (see Authors page)

Revised: 16 May 2016, last major update November 2012

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

PubMed Search: Plasminogen assay [title]

Cite this page: Plasminogen assay. website. Accessed October 25th, 2016.
Definition / General
  • Indications: patients with familial venous thrombosis but no evidence of other hypercoagulable states, occasionally used to monitor thrombolytic therapy or for patients with ligneous conjunctivitis
  • Either functional (based on plasmin activity) or immunologic (based on concentration of plasminogen antigen) (Haemostasis 1988;18:47)

  • Functional assays:
    • Determine plasmin enzyme activity with plasmin-specific chromogenic substrate
    • Add streptokinase to patient plasma, complex cleaves a chromogen releasing a colored compound
    • Color is measured spectrophotometrically and is proportional to plasminogen in sample
    • Expressed as percentage of normal plasma (reference range 75 - 130%)

  • Immunologic assays:
    • Radial immunodiffusion methods
    • Used if dysplasminogenemia is being evaluated
    • Ratio of functional activity to antigen is significantly decreased compared to controls

  • Plasminogen levels are increased by oral contraceptives (which increase cholesterol levels), pregnancy and acute phase reactants
  • Plasminogen levels are decreased by liver disease, thrombolytic therapy and DIC; newborns have levels that are 60% of adults, increase to adult values by age 6 months