Disease overview: Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include myelodysplastic syndromes myelodysplastic syndromes: (my-eh-lo-diss-PLASS-tik SIN-dromez) A group of disorders where the bone marrow does not work well, and the bone marrow cells fail to make enough healthy blood cells. Myelo refers to the bone marrow. Dysplastic means abnormal growth or development. People with MDS have low blood cell count for at… with RS (MDS-RS) and MDS/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T).
Diagnosis: MDS-RS is a lower risk MDS, with single or multilineage dysplasia (MDS-RS-SLD/MLD), <5% bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. (BM) blasts blasts: See Blast Cells. , <1% peripheral blood blasts and ≥15% BM RS (≥5% in the presence of SF3B1 mutations). MDS/MPN-RS-T, now a formal entity in the MDS/MPN overlap syndromes, has diagnostic features of MDS-RS-SLD, along with a platelet platelet: The smallest type of blood cell. Platelets help the blood to clot and stop bleeding. Also called a thrombocyte. count ≥450 × 109 /L and large atypical megakaryocytes.
Mutations and karyotype: Mutations in SF3B1 are seen in ≥80% of patients with MDS-RS-SLD and MDS/MPN-RS-T, and strongly correlate with the presence of BM RS; MDS/MPN-RS-T patients also demonstrate JAK2V617F (50%), DNMT3A, TET2 and ASXL1 mutations. Cytogenetic abnormalities are uncommon in both.
Risk stratification: Most patients with MDS-RS-SLD are stratified into lower risk groups by the revised-IPSS. Disease outcome in MDS/MPN-RS-T is better than that of MDS-RS-SLD, but worse than that of essential thrombocythemia (MPN). Both diseases are associated with a low risk of leukemic transformation.
Treatment: Anemia Anemia: (uh-NEE-mee-uh) A condition in which there is a shortage of red blood cells in the bloodstream. This causes a low red blood cell count. Symptoms of anemia are fatigue and tiredness. and iron overload iron overload: A condition that occurs when too much iron accumulates in the body. Bone marrow failure disease patients who need regular red blood cell transfusions are at risk for iron overload. Organ damage can occur if iron overload is not treated. are complications seen in both and are managed similar to lower risk MDS and MPN. Luspatercept, a first-in-class erythroid maturation agent is now approved for the management of anemia in patients with MDS-RS and MDS/MPN-RS-T. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs remains to be defined.