Review Question - QID 210731

This patient with a normocytic anemia after an infection and bite cells on blood smear most likely has glucose-6-phosphate dehydrogenase deficiency, which should be treated by avoiding certain foods and antibiotics that trigger oxidation.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic disorder that causes an intrinsic hemolytic anemia. Specifically, deficiency in this gene renders red blood cells unable to produce sufficient reducing equivalents of glutathione to appropriately handle oxidative stressors. Therefore, patients with this disease can suffer from acute hemolytic anemia following exposure to stressors including primaquine, dapsone, sulfa drugs, infections, and fava bean ingestion. These episodes lead to precipitation of hemoglobin as Heinz bodies and subsequent removal of these units by the spleen yields characteristic bite cells.

Figure A shows a blood smear with several erythrocytes that are missing a peripheral region of cytoplasm and look as if they have been "bitten". These "bite cells" are characteristic of G6PD deficiency.

Incorrect Answers:
Answer 1: Administration of iron tablets is appropriate for iron deficiency anemia; however, this disease would present with a microcytic rather than normocytic anemia.

Answer 3: Splenectomy is appropriate for a diverse array of intrinsic hemolytic anemias such as sickle cell anemia or hereditary spherocytosis; however, these disease would not present with bite cells.

Answer 4: Supplementation with B vitamins is appropriate for folate or B12 deficiency; however, these diseases would present with a macrocytic rather than normocytic anemia.

Answer 5: Treatment with a chelating agent is appropriate for lead poisoning anemia; however, lead poisoning would lead to a microcytic rather than normocytic anemia.

Bullet Summary:
Hemolytic anemia in G6PD deficiency can be triggered by oxidative stressors such as food, antibiotics, and infections.