idiopathic sideroblastic anemia
idiopathic sideroblastic anemiaAcquired refractory sideroblastic anemia, idiopathic acquired sideroblastic anemia Hematology A pluripotent stem cell defect characterized by ineffective erythropoiesis with a slight ↓ in RBC survival, mild maturational impairment of all hematopoietic cell lines, coupled with defective iron metabolism and iron accumulation; ISA affects older Pts, often related to radio- or chemotherapy, 10-30% of whom later develop acute non-lymphocytic leukemia Clinical Pallor, fatigue, weakness, dyspnea and palpitations on exertion Lab 'Dimorphic' anemia with hypochromic-microcytic and macrocytic features; 40% of erythroblasts are ring sideroblasts, anisocytosis, basophilic stippling, reticulocytes with impaired heme synthesis, ↓ delta ALA synthetase and protease activity Treatment Pyridoxine is often administered, usually without therapeutic response Prognosis ISA
is usually characterized by chronic stable anemia, and less commonly by evolution to leukemia, or to BM failure. Cf Refractory anemia with excess blasts.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.