Microcytic anemia is the most common form of anemia based on the size of the erythrocyte. Within the group, iron deficiency through malnutrition is the most common cause worldwide with the second being anemia of inflammatory disease. Sideroblastic anemia is the third group discussed in this course with both inherited and acquired forms, although inherited sideroblastic anemia known as porphyrias are very rare. Acquired forms associated with both non-clonal and malignant/clonal conditions have been observed.
Iron studies including iron stains, evaluation of blood and urine heme byproducts combined with family history and clinical findings are important diagnostic parameters used for differentiation of causes.
- The presence of normal to high ferritin levels with Pappenheimer bodies in the blood and sideroblasts in the bone marrow will rule out iron deficiency.
- Coexisting IDA with ACI may have normal ferritin levels and will have siderotic granules in bone marrow macrophages. sTfR/log ferritin levels over 2.0 can confirm the coexisting condition.
- Information about patient history will be very important when determining the causes of acquired SA and ACI. Both clonal and congenital-related SA will be dependent on molecular diagnostics with bone marrow evaluations. Relating acquired forms of SA with patient lifestyle, medications, and possible exposure to toxins will be supported by appropriate chemistry analysis.
