aPTT
Single-Factor Assay - 1
If aPTT is abnormal and PT and TT
are normal and normal plasma corrects aPTT then a single-factor deficiency in the intrinsic pathway
may be to blame
Principle :
Factor VIII – most common
Factor IX
Factor XI
Most common
factor deficiencies :
Confirmed by repeating aPTT using
known factor deficient plasma + patient plasma
aPTT will stay
prolonged
Confirmed by the repeating aPTT
using known factor deficient plasma + normal plasma
aPTT will be normal
Procedure :