Acquired inhibitors to the coagulation factor XII associated with liver disease

Three patients with liver disease and prolonged activated partial thromboplastine time (APTT) on routine tests are presented. One woman had metastatic liver disease from gastric carcinoma, a second woman had autoimmune hepatitis, and one man had severe chronic hepatitis B. APTT was not corrected after mixing experiments with 25%, 50%, and 75% of normal pool plasma, indicating the presence of an acquired inhibitor. In all three cases, factor XII coagulant activity was reduced: <1%, <1%, and 3%, respectively, while all of the other coagulation factors were normal. In all three cases no other auto-antibody was detected. In the first patient, APTT was normalized after a left liver lobectomy, whereas the primary lesion remained unresected. In the second patient, the FXII activity was improved after corticosteroid therapy but never returned to normal values. In the third patient, the APTT was improved after hydroxychloroquine therapy. None of the patients had hemorrhagic or thrombotic phenomena.