骨髄異形成症候群におけるSideroblastogramの臨床的意義に関する検討

抄録

Clinical utility of sideroblastogram was evaluated by analyzing the sideroblastogram and other clinical data in 66 patients with myelodysplastic syndrome (MDS) [nine with refractory anemia (RA), 27 with RA with excess blasts (RAEB), 24 with RAEB in transformation (RAEBt), and six with chronic myelomonocytic leukemia (CMMoL)]. The sideroblastogram was constituted based on the classification of erythroblasts according to the numbers of stainable iron granules in their cytoplasm: briefly, type 0 as no granules, type I as 12 granules, type II as 35 granules, type III as more than 6 granules.
The type III dominant sideroblastogram (type III predominace) was observed in 73% of the patients with MDS in contrast with type 0I predominance in 100% of the healthy volunteers. Although type III predominance appeared distinctly in patients who presented erythroid morphological abnormalities, 50% of the patients without abnormalities also had type III predominance. Patients with type III predominance had more severe macrocytic anemia compared with other dominant types, but type III predominance did not influence the disease prognosis. In two cases the sideroblastogram was normalized at complete remission, and returned to type III dominance at recurrence of the disease.
The type III dominant sideroblastogram reflects the disorders of iron metabolism in erythroblasts, and the normalization of the sideroblastogram indicates the appearance of normal erythropoiesis from the normal clone in marrow. We conclude that the sideroblastogram is useful not only in diagnosing MDS but also in clinical evaluation of the therapeutic effect.