APTT Blood Test (Activated Partial Thromboplastin Time)
APTT Blood Test is one of several blood Coagulation tests. It measures how long it takes your blood to form a clot. The APTT has used deficiencies intrinsic Coagulation factors (prothrombin v, viii, ix, x, xi, xii) and fibrinogen that monitor heparin therapy It investigates the unexplained bleeding and clotting disorder. The APTT is 1 of several blood coagulation tests. It measures how long it takes your blood to form a clot.
Platelets poor plasma is incubated at 37°C then partial thromboplastin (phospholipid substitute) and surface activator Kalin, micronized silica are added Ca cl2 are added and time is taken for the mixture to clot.
Why Need This Test:
If you have a bleeding disorder, such as von Willebrand disease or another disease that prevents your blood from clotting, this test can help find out where the problem is.
Causes Of Prolonged APTT:
- Haemophilia A ( Deficiency of factor XII)
- Haemophilia B (Deficiency of factor (x)
- Von Willebrand disease
- Phospholipid Antibodies
Effect of APTT:
Drugs that may prolong test values, Including:
- Ascorbic Acid
What Happens when APT is High:
If the number of APTT is high than the normal it could Several things from bleeding disorders to liver disease. Then you get other test at the Condition,
- Anticoagulation effect
- Heparin contaminated Samples
- Factor deficiencies
- Factor inhibiton
How to Perform this Test:
- Phospholipid or partial Thromboplastin
- Platelet Poor Plasma
- Central Plasma
- Ca cl2 0.025 M Solution
- Test Tube
- Stop watch
Take 1ooμl of plasma in a glass tube, Add 100μl of APTT reagent, (Liquicelin E), and Place a water bath in an incubator for 5 minutes. After 5 minutes Add 100μl of Cacl2 and start a Stopwatch. Mix the tube gently by tilting the tube, Note the clotting time.
Normal Range of APTT is 38 to 42 Seconds.
- Hemophilia A and B
- Liver disease
- Massive transfusion of whole blood
- Administration of Heparin
- Factor ix, xi, xii