Coagulation
Coagulation laboratory tests
Plasminogen assay
Author: Jeremy C. Parsons, M.D.
Last author update: 1 November 2012
Last staff update: 23 September 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Plasminogen assay [title]
Cite this page: Parsons JC. Plasminogen assay. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/coagulationplasminogen.html. Accessed June 5th, 2023.
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
Interpretation
- 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
