Coagulation
Coagulation laboratory tests
tPA assay

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

Revised: 17 May 2016, last major update November 2012

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

PubMed Search: tPA assay [title]

Table of Contents
Definition / General | Laboratory
Cite this page: tPA assay. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/coagulationtPAassay.html. Accessed December 6th, 2016.
Definition / General
  • tPA activity / antigen and PAI-1 activity / antigen are used to evaluate fibrinolysis; often PAI-1 activity and tPA antigen are ordered together
  • PAI-1 rapidly forms a complex with free tPA in the specimen
  • Not recommended for routine clinical laboratories due to complexity and special handling requirements
  • Can also measure tPA plasma concentration by ELISA or other immunologic assays
  • Resting level is usually low, not clinically significant
  • Post-stimulation level (such as after venous occlusion for 10 minutes) may be more useful
  • Higher levels in patients with acute paraquat intoxication (J Korean Med Sci 2011;26:474)
Laboratory
  • Must first inhibit interaction of tPA with PAI1 (its functional inhibitor) by acidifying plasma
  • Determine activity by measuring plasmin activity from conversion of plasminogen