本態性血小板血症8例の検討

抄録

Eight patients with essential thrombocythemia were diagnosed according to the criteria proposed by the Polycythemia Vera Study Group. Ages ranged from 19∼83 years with a median of 63. Five patients had thrombotic complications, one had hemorrhagic complications and two were asymptomatic. The hemoglobin level ranged from 11.7 to 15.3 g/dl. White blood cell counts ranged from 7,800 to 46,000/μl. Platelet counts ranged from 109x to 282×10⁴/μl. The most common morphologic abnormalities were giant platelets. Six patients exhibited at least some impairmant of aggregation with ADP or collagen. Platelet adhesion studies were normal in 6 patients. Spontaneous platelet aggregation was noted in all patients when patient's platelet rich plasma was not diluted. The occurrence of thrombosis and/or hemorrhage showed no correlation with either the platelet count or platelet function tests. In 6 of 8 cases, the karyotypes were normal. One revealed 46, XX, t (20; 22) (q13.3; q13) and in another case, the percentages of tetraploid chromosome constitution among all analysed metaphases were increased. The number of CFU-C, CFU-E and BFU-E-derived colonies in peripheral blood increased in all examined cases. CFU-C and BFU-E-derived colonies in bone marrow revealed normal or increased in numbers. The growth of CFU-E-derived colonies in bone marrow showed no consistent pattern. In two of six cases, spontaneous erythroid growths, which could be grown in the culture condition without added Epo as well as BPA, were observed.