Acquired factor VIII inhibitor preceding chronic lymphocytic leukemia

Summary An acquired factor VIII inhibitor was found in an 82-year-old woman who presented with numerous spontaneously appearing ecchymoses. Coagulation studies revealed the presence of a prolonged activated partial thromboplastin time that was not corrected by 11 mixture with normal fresh plasma after a 2–h incubation. Factor VIII: C was 4%, and the titer for factor VIII inhibitor was 9 Bethesda units. Three months later, after a retroperitoneal hemorrhage, a lymphocytosis was found in her peripheral blood with morphological and surface immunophenotype characteristics of B-cell chronic lymphocytic leukemia, later confirmed by bone marrow morphological and immunocytochemical examinations. To our knowledge, this is the first report of an autoimmune factor VIII inhibitor associated with chronic lymphocytic leukemia.