Difference Between APTT and PTT

Partial thromboplastin time (PTT) and activated partial thromboplastin time (aPTT) are used to test for the same functions; however, in aPTT, an activator is added that speeds up the clotting time and results in a narrower reference range.

1. What is difference between PT and PTT?
2. Why is aPTT called aPTT?
3. What does PT and aPTT stand for?
4. Why aPTT test is done?
5. What is a normal PTT?
6. What happens if PTT is high?
7. What is aptt normal range?
8. What is PT APTT and INR?
9. What happens if PTT is low?
10. Is PT the same as INR?
11. What causes low PTT?
12. What causes high aPTT?

What is difference between PT and PTT?

Two laboratory tests are used commonly to evaluate coagulation disorders: Prothrombin Time (PT) which measures the integrity of the extrinsic system as well as factors common to both systems and Partial Thromboplastin Time (PTT), which measures the integrity of the intrinsic system and the common components.

Why is aPTT called aPTT?

The term 'Activated Partial Thromboplastin Time (APTT)' derives from the original form of the test (devised in 1953) in which only the phospholipid concentration of the test was controlled (as opposed to the phospholipid and the surface activator concentration) and the name 'partial thromboplastin' was applied at the ...

What does PT and aPTT stand for?

D010314. The partial thromboplastin time (PTT) or activated partial thromboplastin time (aPTT or APTT) is a blood test that characterizes coagulation of the blood. A historical name for this measure is the kaolin-cephalin clotting time (KCCT), reflecting kaolin and cephalin as materials historically used in the test.

Why aPTT test is done?

The aPTT test is used when someone has unexplained bleeding or clotting. Along with the PT test (which evaluates the extrinsic and common pathways of the coagulation cascade), the aPTT is often used as a starting place when investigating the cause of a bleeding or thrombotic (blood clot) episode.

What is a normal PTT?

Measured in seconds to clot formation, normal PTT can vary based on laboratory or institution; however, normal PTT is between 25 to 35. PTT ranges are used to classify heparin dosing schemes as low or high intensity and to ensure effective dosing.

What happens if PTT is high?

Your PTT test results will show how much time it took for your blood to clot. Results are usually given as a number of seconds. If your results show that your blood took a longer-than-normal time to clot, it may mean you have: A bleeding disorder, such as hemophilia or von Willebrand disease.

What is aptt normal range?

The reference range of the aPTT is 30-40 seconds. The reference range of the PTT is 60-70 seconds. In patients receiving anticoagulant therapy, the reference range is 1.5-2.5 times the control value in seconds.

What is PT APTT and INR?

Individually these tests are commonly referred to as a prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR). These pre-surgical tests determine whether your blood clots normally and are used to avoid excessive bleeding during surgery.

What happens if PTT is low?

If the amount of one or more factors is too low, or if the factors cannot do their job properly, then a stable clot may not form and bleeding continues. With a PTT, your result is compared to a normal reference interval for clotting time.

Is PT the same as INR?

A prothrombin time (PT) is a test used to help detect and diagnose a bleeding disorder or excessive clotting disorder; the international normalized ratio (INR) is calculated from a PT result and is used to monitor how well the blood-thinning medication (anticoagulant) warfarin (Coumadin®) is working to prevent blood ...

What causes low PTT?

deficiency of blood clotting factors. von Willebrand disease (a disorder that causes abnormal blood clotting) disseminated intravascular coagulation (a disease in which the proteins responsible for blood clotting are abnormally active) hypofibrinogenemia (deficiency of the blood clotting factor fibrinogen)

What causes high aPTT?

Any deficiency or inhibitor of the clotting factors within the intrinsic or common pathways will result in a prolonged APTT. The factors involved in the intrinsic and common pathways are II (prothrombin), V, VIII, IX, X, XI, XII, and fibrinogen (factor I).