Thromboplastin time partial

PTT is the acronym for "partial thrombiplastin time" a laboratory test to check blood clotting.

The determination of the partial thrombiplastin time is used on the one hand to diagnose coagulation disorders and on the other hand to assess the course of taking certain medications.

In everyday clinical practice, PTT is determined in patients treated with anticoagulant drugs such as heparin or hirudin analogues.

The standard PTT value is 20 to 38 seconds.

A shortened PTT time is measured at:

• Factor V Leiden mutation
• Lack of protein S or protein C (congenital or acquired through liver or chronic intestinal diseases)
• Antithrombin Deficiency

A prolonged PTT or aPTT value occurs in various coagulation disorders:

• deficiency of certain coagulation factors (I, II, V, X, XI and XII)
• Haemophilia (lack of factor VIII or IX)
• Antiphospholipid antibody syndrome (so-called lupus anticoagulant)
• Von Willebrand-Jürgens Syndrome
• Consumption coagulopathy (disseminated intravascular coagulation)
• Vitamin K Deficiency
• Liver damage
• In addition, various drugs inhibit blood clotting and thus prolong PTT. This applies, for example, to heparin, hirudin analogues and acetylsalicylic acid (ASA).