Acquired inhibitors to the coagulation factor XII associated with liver disease

Three patients with liver disease and prolonged activated partial thrombopl astine time (APTT) on routine tests are presented. One woman had metastatic liver disease from gastric carcinoma, a second woman had autoimmune hepati tis, and one man had severe chronic hepatitis B. APTT was not corrected aft er mixing experiments with 25%, 50%, and 75% of normal pool plasma, indicat ing the presence of an acquired inhibitor. In all three cases, factor XII c oagulant activity was reduced: <1%, <1%, and 3%, respectively, while all of the other coagulation factors were normal. In all three cases no other aut o-antibody was detected. In the first patient, APTT was normalized after a left liver lobectomy, whereas the primary lesion remained unresected. In th e second patient, the FXII activity was improved after corticosteroid thera py but never returned to normal values. In the third patient, the APTT was improved after hydroxychloroquine therapy. None of the patients had hemorrh agic or thrombotic phenomena. (Am J Gastroenterol 1999;94: 2551-2553. (C) 1 999 by Am. Coll. of Gastroenterology).