PLASMINOGEN ACTIVATOR
INHIBITOR 1 (PAI-1)

Background

The type 1 plasminogen activator inhibitor (PAI-1) is a primary regulator of the fibrinolytic system in vivo. PAI-1 binds to tissue plasminogen activator and inhibits plasminogen activation, which decreases fibrinolysis. A single guanosine insertion/deletion (4G or 5G) 675 base pairs from the start site of the genes promoter region affects an individual's predisposition for thrombosis.
Studies have shown a correlation between PAI-1 levels in plasma and the 4G/5G polymorphism. Subjects with the 4G/4G genotype have plasma PAI-1 concentrations that are 25% higher than those with the 5G/5G genotype. Increased PAI activity may be associated with increased risk for venous thrombosis and myocardial infarction. The prevalence of the 4G/4G genotype in the normal population is 26%.
An der Stelle -675 vor Beginn des PAI-1 Gens (SERPINE1) können 4 oder 5 Guanosin-Nukleotide stehen und die Bindung von Transkriptionsfaktoren beeinflussen. Das Vorliegen des 4G-Genotyps führt zu einer vermehrten Transkription des Gens und damit zu einem erhöhten PAI-1 Spiegel. Das resultiert in Folge in einer verminderten fibrinolytischen Aktivität des Plasminogenaktivators.

Indications for testing

Patients presenting with family histories of early heart disease or venous thrombosis

Pregnant women with past complications during pregnancy.

Specimen Shipping

Literature:

Tsantes AE et al. Association between the plasminogen activator inhibitor-1 4G/5G polymorphism and venous thrombosis. A meta-analysis. Thromb Haemost. 2007;97:907-13.
Fabbro D et al. Association between plasminogen activator inhibitor 1 gene polymorphisms and preeclampsia. Gynecol Obstet In-vest. 2003;56:17-22.