Plasminogen Activator Inhibitor 1 (PAI-1) Activity
Also known as: PAI-1
Use
Plasminogen activator inhibitor 1 (PAI-1) is a member of a family of proteins that inhibit plasminogen activators. It serves as the primary inhibitor of tissue plasminogen activator (tPA) and other plasminogen activators in the blood, thus limiting the production of plasmin and keeping the fibrinolysis process in check. Increased levels of PAI-1 are associated with an increased incidence of acute coronary syndrome, chronic and acute coronary artery disease, and restenosis after coronary angioplasty. PAI-1 levels are determined genetically and have been associated with a variety of atherosclerotic risk factors, insulin resistance syndrome, and diabetes mellitus. It acts as a prothrombic factor in thromboembolic disorders and influences the effectiveness of antithrombolytic therapy.
Special Instructions
If the patient's hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted. Please refer to the Sample Collection for Coagulation Testing for directions. To avoid delayed turnaround times, submit separate frozen specimens for each test requested.
Limitations
PAI-1 is an acute-phase reactant and can become transiently elevated by infection, inflammation, or trauma. Levels increase during pregnancy, and certain polymorphisms in the PAI-1 gene can lead to increased blood concentrations. Weight loss and treatments that lower triglyceride and/or cholesterol levels have been shown to lower PAI-1 levels.
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 5975-8
- 5975-8
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
0.5 mL
Minimum Volume
Not provided
Container
Blue-top (sodium citrate) tube
Collection Instructions
Blood should be collected in a blue-top tube containing 3.2% buffered sodium citrate. Evacuated collection tubes must be filled to completion to ensure a proper blood to anticoagulant ratio. The sample should be mixed by gentle inversion at least six times to ensure adequate mixing. When collecting with a 'butterfly', use a discard tube. Centrifuge and remove the plasma using a plastic transfer pipette without disturbing the cells. Transfer the plasma into a Labcorp PP transpak frozen purple tube with screw cap. Freeze immediately and maintain frozen until tested.
Storage Instructions
Freeze.
Causes for Rejection
Specimen received unfrozen; noncitrated plasma specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Unstable |
| Refrigerated | Unstable |
| Frozen | 11 days |