Overview of Decreased Erythropoiesis

ByGloria F. Gerber, MD, Johns Hopkins School of Medicine, Division of Hematology
Reviewed/Revised Jun 2023
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    Anemia, a decrease in the number of red blood cells (RBCs), hemoglobin (Hb) content, or hematocrit (Hct), can result from decreased RBC production (erythropoiesis), increased RBC destruction, blood loss, or a combination of these factors. (See also Approach to the Patient with Anemia.)

    Anemias due to decreased erythropoiesis (termed hypoproliferative anemias) are recognized by a reticulocyte count that is inappropriately low for the degree of the anemia.

    The RBC indices, mainly the mean corpuscular volume (MCV), can narrow the differential diagnosis of deficient erythropoiesis and help determine what further testing is necessary.

    Microcytic anemias result from deficient or defective heme or globin synthesis. Microcytic, hypoproliferative anemias include

    Patients with a microcytic anemia typically require evaluation of iron stores.

    Normocytic anemias are characterized by a normal MCV (80 to 100 fL) and normochromic indices. The two most common causes are

    Acquired primary bone marrow disorders such as aplastic anemia, pure red cell aplasia, and myelodysplastic syndrome (MDS) can also manifest with a normocytic anemia.

    Macrocytic anemias can be caused by impaired DNA synthesis leading to megaloblastosis, as occurs with

    Other causes of macrocytic anemia include

    Some patients with hypothyroidism have macrocytic RBC indices, including some without anemia.

    Anemias can have variable findings on the peripheral smear. The anemia of chronic disease may be microcytic or normocytic. Anemias due to myelodysplastic syndromes may be normocytic, macrocytic, or even microcytic. Anemias due to endocrine disorders (such as hypothyroidism) or elemental deficiencies (eg, , zinc deficiency) can have variable manifestations, including a normocytic or macrocytic anemia.

    Treatment of deficient RBC production depends on the cause.

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