Reference Range(s)

Clinical Significance

The aPTT is a screening test that will detect deficiencies or inhibitors to the intrinsic (Factors VIII, IX, XI and XII) and common (Factors II, V, X and fibrinogen) pathway coagulation factors.

Test FAQ

Partial Thromboplastin Time, Activated (aPTT)

Alternative Name(s)

APTT,PTT

Methodology

Photo-optical Clot Detection

Limitations

Expected impact by therapeutic levels (potential interference depends upon drug concentration): Warfarin: prolonged; Heparin (UFH or LMWH): prolonged; Dabigatran or Argatroban (Thrombin Inhibitors): prolonged; Rivaroxaban or Apixaban (Factor Xa Inhibitors): prolonged.