Sideroblastic anemias



Sideroblastic anemias





Sideroblastic anemias, a group of heterogenous disorders, produce a common defect—failure to use iron in hemoglobin (Hb) synthesis, despite the availability of adequate iron stores. These anemias may be hereditary or acquired; the acquired form, in turn, can be primary or secondary.

Hereditary sideroblastic anemia often responds to treatment with pyridoxine. Correction of the secondary acquired form depends on the causative disorder; the primary acquired (idiopathic) form, however, resists treatment and usually proves fatal within 10 years after onset of complications or a concomitant disease.


Causes

Hereditary sideroblastic anemia appears to be transmitted by X-linked inheritance, occurring mostly in young males; females are carriers and usually show no signs of this disorder.

The acquired form may be secondary to ingestion of, or exposure to, toxins, such as alcohol and lead, or to drugs, such as isoniazid and chloramphenicol. It can also occur as a complication of other diseases, such as rheumatoid arthritis, lupus erythematosus, multiple myeloma, tuberculosis, and severe infections.

The primary acquired form, known as refractory anemia with ringed sideroblasts, is most common in elderly people. It’s often associated with thrombocytopenia or leukopenia as part of a myelodysplastic syndrome.

In sideroblastic anemia, normoblasts fail to use iron to synthesize Hb. As a result, iron is deposited in the mitochondria of normoblasts, which are then called ringed sideroblasts.

Jun 16, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Sideroblastic anemias
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