inhibitor syndrome
Last reviewed 01/2018
The presence of circulating inhibitors of blood coagulation is indicated by:
- an increased partial thromboplastin time which cannot be corrected by addition of normal plasma; formally tested as a 30 minute 1:1 mix test - incubation of patient plasma plus an equal volume of normal plasma
- normal or increased prothrombin time
Increased PTT and PT occurs only when specific coagulation factors fall to below 30% of their normal values.
Two types of circulating inhibitor are recognised:
- antibodies directed against specific coagulation proteins
- inhibitors directed against phospholipid function - principally, lupus anticoagulant