1.3 Hematology: Hypochromic and Microcytic Anemias

The osmotic fragility test result in a patient with thalassemia major would most likely be:

A. Increased

B. Decreased

C. Normal

D. Decreased after incubation at 37°C

B. Decreased

B The osmotic fragility is decreased because numerous target cells are present and have increased surface volume in thalassemia major patients.

All of the following are characteristic findings in a patient with iron deficiency anemia except:

A. Microcytic, hypochromic red cell morphology

B. Decreased serum iron and ferritin levels

C. Decreased total iron-binding capacity (TIBC)

D. Increased RBC protoporphyrin

C. Decreased total iron-binding capacity (TIBC)

C In iron deficiency anemia (IDA), there is an increase in TIBC and in RBC protoporphyrin. The serum iron and ferritin levels are decreased. IDA is characterized by a microcytic hypochromic anemia.

Iron deficiency anemia may be distinguished from anemia of chronic infection by:

A. Serum iron level

B. Red cell morphology

C. Red cell indices

D. Total iron-binding capacity

D. Total iron-binding capacity

D In iron deficiency anemia, the serum iron and ferritin levels are decreased and the total iron-binding capacity and RBC protoporphyrin are increased. In chronic disease, serum iron and TIBC are both

decreased because the iron is trapped in reticuloendothelial (RE) cells, and is unavailable to the red cells for hemoglobin production.

Which anemia has red cell morphology similar to that seen in iron deficiency anemia?

A. Sickle cell anemia

B. Thalassemia syndrome

C. Pernicious anemia

D. Hereditary spherocytosis

B. Thalassemia syndrome

B Iron deficiency anemia and thalassemia are both classified as microcytic, hypochromic anemias. Iron deficiency anemia is caused by defective heme synthesis; whereas thalassemia is caused by decreased globin chain synthesis.

Iron deficiency anemia is characterized by:

A. Decreased plasma iron, decreased % saturation, increased total iron-binding capacity (TIBC)

B. Decreased plasma iron, decreased plasma ferritin, normal RBC porphyrin

C. Decreased plasma iron, decreased % saturation, decreased TIBC

D. Decreased plasma iron, increased % saturation, decreased TIBC

A. Decreased plasma iron, decreased % saturation, increased total iron-binding capacity (TIBC)

A Iron deficiency anemia is characterized by decreased

plasma iron, increased TIBC, decreased % saturation, and microcytic, hypochromic anemia. Iron deficiency occurs in three phases: iron depletion, iron-deficient erythropoiesis, and iron deficiency anemia.

Storage iron is usually best determined by:

A. Serum transferrin levels

B. Hgb values

C. Myoglobin values

D. Serum ferritin levels

D. Serum ferritin levels

D Ferritin enters the serum from all ferritin-producing tissues, and therefore is considered to be a good indicator of body storage iron. Because iron stores must be depleted before anemia develops, low serum ferritin levels precede the fall in serum iron associated with iron deficiency anemia.

All of the following are associated with sideroblastic anemia except:

A. Increased serum iron

B. Ringed sideroblasts

C. Dimorphic blood picture

D. Increased RBC protoporphyrin

D. Increased RBC protoporphyrin

D Sideroblastic anemia has a decreased red cell protoporphyrin. The defect in sideroblastic anemia involves ineffective erythropoiesis. The failure to produce RBC protoporphyrin occurs because the nonheme iron is trapped in the mitochondria and is unavailable to be recycled.

What is the basic hematological defect seen in patients with thalassemia major?

A. DNA synthetic defect

B. Hgb structure

C. β-Chain synthesis

D. Hgb phosphorylation

C. β-Chain synthesis

C In thalassemia major, there is little or no production of the β-chain, resulting in severely depressed or no synthesis of Hgb A. Severe anemia is seen, along with skeletal abnormalities and marked splenomegaly. The patient is usually supported with transfusion therapy.

Which of the following is the primary Hgb in patients with thalassemia major?

A. Hgb D

B. Hgb A

C. Hgb C

D. Hgb F

D. Hgb F

D Patients with thalassemia major are unable to synthesize the β-chain; hence, little or no Hgb A is produced. However, γ chains continue to be synthesized and lead to variable elevations of Hgb F in these patients.

A patient has an Hct of 30%, a hemoglobin of 8 g/dL, and an RBC count of 4.0 × 1012/L. What is the morphological classification of this anemia?

A. Normocytic normochromic

B. Macrocytic hypochromic

C. Microcytic hypochromic

D. Normocytic hyperchromic

C. Microcytic hypochromic

C The indices will provide a morphological classification of this anemia. The MCV is 75 fL (reference range 80-100 fL), the MCH is 20.0 pg (reference range 27-31 pg), and the MCHC is 26.6% (reference range 32%-36%). Therefore, the anemia is microcytic hypochromic.

In which of the following conditions is Hgb A2 elevated?

A. Hgb H

B. Hgb SC disease

C. β-Thalassemia minor

D. Hgb S trait

C. β-Thalassemia minor

C Hgb A2 is part of the normal complement of adult Hgb. This Hgb is elevated in β-thalassemia minor because the individual with this condition has only one normal β-gene; consequently, there is a slight elevation of Hgb A2 and Hgb F.

Which of the following parameters may be similar for the anemia of inflammation and iron deficiency anemia?

A. Normocytic indices

B. Decreased serum iron concentration

C. Ringed sideroblasts

D. Pappenheimer bodies

B. Decreased serum iron concentration

B Thirty to fifty percent of the individuals with the anemia of chronic inflammation demonstrate a microcytic hypochromic blood picture with decreased serum iron. Serum iron is decreased because it is unable to escape from the RE cells to be delivered to the nucleated red cells in the bone marrow.