1989 Volume 30 Issue 8 Pages 1271-1274
A case of polycythemia vera with an inhibitor against factor XII was reported. A 60-year-old female was admitted to Hokkaido University School Hospital because of erythrocytosis and hepatosplenomegaly. The hemoglobin was 22.5 g/dl and white cell count was 9,500/μl without immature cells. The platelet count was 484,000/μl. Bone marrow specimens showed marked hypercellularity. Philadelphia chromosome was not found on chromosome analysis. She was diagnosed as polycytemia vera according to the criteria of polycythemia Vera Study Group.
Activity of factor XII was found to be decreased on the initial examination, but she had no personal and familial history of bleeding. In order to clarify the cause of decreased activity of factor XII, her plasma was mixed with normal plasma, and then examined PTT using factor XII deficient plasma. Her plasma mixed with equivalent normal plasma did not show the correction of prolonged PTT. It was suggested that an inhibitor of her plasma was included in the IgG fraction using gelchromatography. The patient was treated with phlebotomy and administration of N4-palmitoil (1- -D-arabinofurasyl) cytosine (derivative of cytosine arabinoside; PLAC) 200 mg/day and Busulfan (1 mg/day). Factor XII was not corrected by phlebotomy, but corrected gradually by administratin of PLAC and Busulfan.
