Related Experiment Video
Updated: Aug 12, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
An acquired inhibitor to factor XIII A case report
An elderly woman presented with a postoperative bleeding problem, and a presumptive diagnosis of factor XIII (fibrin-stablilizing factor) deficiency was made. However, on further testing, an inhibitor to factor XIII was detected. She was on isoniazid (INH) therapy at the time. INH has been implicated in other patients who have developed inhibitors to factor XIII, and it was felt that this was the reason for this patient developing the inhibitor. The patient subsequently died from a cerebral haemorrhage, a well-described complication of factor XIII deficiency.
An elderly woman presented with a postoperative bleeding problem, and a presumptive diagnosis of factor XIII (fibrin-stablilizing factor) deficiency was made. However, on further testing, an inhibitor to factor XIII was detected. She was on isoniazid (INH) therapy at the time. INH has been implicated in other patients who have developed inhibitors to factor XIII, and it was felt that this was the reason for this patient developing the inhibitor. The patient subsequently died from a cerebral haemorrhage, a well-described complication of factor XIII deficiency.
Related Concept Videos
Anticoagulant Drugs: Low-Molecular-Weight Heparins
Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
Venous Thrombosis III: Interprofessional Care

