Table 3.

Initial assessment of prolonged PT and aPTT in a patient with bleeding

PT	aPTT	Causes
Normal	Normal	von Willebrand's disease FXIII deficiency, Dysfibrinogenemia	Platelet dysfunction α-antiplasmin deficiency
		Mixing study corrects	Mixing study does not correct
Prolonged	Normal	Hereditary Isolated FVII deficiency Acquired Vitamin K deficiency/ antagonists Severe liver impairment	Inhibitors Lupus anticoagulant FVII inhibitor (rare)
Normal	Prolonged	Bleeding FVIII/vWD deficiency, FIX/XI deficiency No bleeding FXII, HMWK, prekallikrein	Bleeding FVIII, FIX, FXI inhibitor, heparin No bleeding FXII inhibitor, lupus anticoagulant HMWK, prekallikrein
Prolonged	Prolonged	FII, FV, FX deficiency FV and FVIII deficiency Severe liver impairment Vitamin K deficiency/antagonist DIC	FII, FV, FX inhibitor Lupus anticoagulant