Acquired factor XIII inhibitor: clinical features, treatment, fibrin structure and epitope determination.

Acquired factor XIII (FXIII) deficiency, arising from an autoantibody against factor XIII, is a rare bleeding disorder. This autoimmune disorder most commonly occurs in the elderly. Patients who develop such acquired FXIII inhibitors may present with catastrophic bleeding events and are hard to be diagnosed with the normal general coagulation tests. Though the disease is relatively rare, it is known to cause significant mortality. In this article we briefly describe a patient who presented with extensive bleeding and a normal activated partial thromboplastin time and prothrombin time (PT), but had an acquired inhibitor to FXIII; her primary disease was systemic lupus erythematosus (SLE). Also, we will focus on the clinical features, treatment modalities, fibrin structure and epitope identification for acquired factor XIII inhibitor with a review of the literature.