Sideroblastinen

Sideroblastinen, commonly referred to as sideroblasts, are nucleated erythroblasts in which iron accumulates as granules within mitochondria. These iron-loaded mitochondria can be visualized in bone marrow cells after staining with Prussian blue. When a distinctive ring of iron surrounds the nucleus, the cells are described as ring sideroblasts.

Ring sideroblasts are characteristic of sideroblastic anemia, a group of disorders caused by impaired incorporation of iron into heme during red blood cell development. In the bone marrow, ring sideroblasts are counted and analyzed to help classify the condition. The presence of more than a few ring sideroblasts or a high proportion of erythroid precursors with ring sideroblasts supports the diagnosis of sideroblastic anemia, and many guidelines distinguish this pattern in myelodysplastic syndromes as MDS with ring sideroblasts.

Sideroblastic anemia can be congenital or acquired. Congenital forms often involve mutations in the ALAS2 gene, which encodes an enzyme essential for heme synthesis. Acquired forms include myelodysplastic syndromes (especially MDS with ring sideroblasts and SF3B1 mutations), chronic alcohol use, copper deficiency, lead poisoning, zinc excess, and certain medications such as linezolid or isoniazid. The underlying cause influences both prognosis and treatment.

Diagnosis relies on bone marrow examination with Prussian blue staining to detect sideroblasts, complemented by iron studies and clinical assessment to identify causative factors. Management focuses on addressing the underlying cause, providing supportive care for anemia, and considering disease-modifying therapy in select cases (for example, MDS-associated sideroblastic anemia). The prognosis varies with etiology and the extent of ring sideroblast formation.