骨髄増殖異常症候群に合併した赤芽球癆に免疫抑制剤が有効であった1例

抄録

A case of pure red cell aplasia (PRCA) which developed in the course of myelodysplastic syndrome (MDS) is reported. A 62-year-old man was admitted in January, 1982, because of severe anemia. On physical examination, the patient was anemic, and laboratory examination showed normochromic and normocytic anemia. Bone marrow aspiration showed hypercellular marrow and karyorrhexis was present in the erythroid series. Ferrokinetic studies revealed ineffective erythropoiesis. CFU-C and CFU-E were markedly decreased. He was diagnosed as having MDS and was treated with vitamin B₆ and folic acid. However, anemia gradually progressed and he was readmitted in May, 1982. On laboratory examination, reticulocytes were not seen in the peripheral blood, and bone marrow aspiration showed marked erythroblastopenia. A diagnosis of PRCA was made. Peripheral blood mononuclear cells, but not serum, from the patient suppressed CFU-E of normal bone marrow in vitro. He was started on prednisolone 60 mg daily, and dramatic improvement in anemia was encountered. With tapering of prednisolone, however, anemia developed again. Cyclophosphamide, 75 mg daily, was administered, and anemia was improved.
Although mechanisms developing PRCA in the course of preleukemic state are not known, our study suggests that there may be a population of mononuclear cells in the patient's peripheral blood which suppresses normal CFU-E.