According to the International Society on Thrombosis (ISTH), the guidelines for diagnostic criteria for LA/aPL include the demonstration of which of the following?
A) Normal phospholipid-dependent coagulation reaction
B) Absence of a clotting factor
C) Presence of an inhibitor
D) Abnormal PT

Question

Quizplus · Accepted Answer

The ISTH guidelines for the diagnosis of lupus anticoagulant (LA)/antiphospholipid (aPL) include the demonstration of the presence of an inhibitor. This is because lupus anticoagulant is an antibody that interferes with normal phospholipid-dependent coagulation tests, leading to a prolonged clotting time in vitro, which indicates the presence of an inhibitor rather than a deficiency of clotting factors or abnormalities in PT (prothrombin time).

According to the International Society on Thrombosis (ISTH), the Guidelines