Coagulation
Coagulation laboratory tests
tPA assay
Author: Jeremy C. Parsons, M.D.
Last author update: 1 November 2012
Last staff update: 11 May 2021
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: tPA assay [title]
Cite this page: Parsons J. tPA assay. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/coagulationtPAassay.html. Accessed December 23rd, 2024.
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
