ＩＴＰおよび類縁疾患におけるビスコクラウリン型アルカロイド製剤の血小板増加作用と骨髄の変化：光顕および電顕的検討

Abstract

Cepharanthin (Ceph), a complex of biscoclaurine alkaloids, is known to be effective for increasing platelet counts particularly in patients with idiopathic thrombocytopenic purpura (ITP). We investigated the thrombopoietic effect of a high-dose Ceph treatment on thrombocytopenic patients. The morphological changes of the bone marrow in these patients were investigated by light and electron microscopy. The diseases consisted of 7 ITPs, 4 refractory cytopenias (RCs), and 2 aplastic anemias (AAs). The patients were divided into two groups: (1) prednisolone (PSL)+Ceph and (2) Ceph groups. The PSL+Ceph group consisted of 5 ITP and 1 RC-patients. These patients were refractory to prior PSL therapy, and were subsequently given 60mg of Ceph daily in addition to the PSL therapy. The Ceph group consisted of 2 ITP, 3 RC and 2 AA-patients. In the PSL+Ceph group, 5 out of 6 patients showed significant increase in platelet counts after the initiation of additional Ceph treatment. In the Ceph group, 2 RC patients showed slight increase in platelet counts. Thus, the Ceph treatment was found to be effective for increasing platelet counts, particularly when it was combined with the PSL therapy. To investigate the changes of bone marrow cells caused by the Ceph treatment, the bone marrows of the patients in the PSL+Ceph and Ceph groups were examined by light and electron microscopy. The following findings were seen in the bone marrow obtained during the Ceph treatment: Most of the macrophages showed a foam cell appearance. These cells had many vacuoles containing myelin-like structures. Some macrophages also showed remarkable acid phosphatase activity. Megakaryocytes had aggregated glycogen particles in the cytoplasm. These morphological findings were considered to be caused by the Ceph treatment, and they might be related to the mechanisms of thrombopoiesis.