ASCP Hematology 2 — Questions and Answers
Question 1: Sickle cell disease is caused by a substitution of which amino acid in the beta-globin chain?
- Lysine for glutamic acid at position 6
- Valine for glutamic acid at position 6 (Correct answer)
- Alanine for glycine at position 6
- Proline for valine at position 6
Correct answer: Valine for glutamic acid at position 6
In sickle cell disease, valine substitutes for glutamic acid at position 6 of the beta-globin chain.
Question 2: What is the function of the reticuloendothelial system in red blood cell destruction?
- Synthesizes new RBCs
- Removes senescent RBCs via phagocytosis (Correct answer)
- Produces clotting factors
- Regulates platelet production
Correct answer: Removes senescent RBCs via phagocytosis
The reticuloendothelial system (spleen, liver, bone marrow macrophages) phagocytizes and destroys aging red blood cells.
Question 3: Which finding on a CBC is most indicative of hemolytic anemia?
- Decreased reticulocyte count
- Increased reticulocyte count (Correct answer)
- Decreased MCV
- Increased MCH
Correct answer: Increased reticulocyte count
An elevated reticulocyte count reflects increased bone marrow production in response to accelerated RBC destruction.
Question 4: Which stain is used to identify reticulocytes on a peripheral smear?
- Wright-Giemsa stain
- Prussian blue stain
- New methylene blue stain (Correct answer)
- Periodic acid-Schiff stain
Correct answer: New methylene blue stain
New methylene blue is a supravital stain that precipitates residual RNA in reticulocytes, making them visible.
Question 5: A patient has an MCV of 110 fL. Which condition is most likely?
- Iron deficiency anemia
- Thalassemia minor
- Vitamin B12 deficiency (Correct answer)
- Anemia of chronic disease
Correct answer: Vitamin B12 deficiency
An elevated MCV >100 fL indicates macrocytic anemia, most commonly caused by vitamin B12 or folate deficiency.
Question 6: Which leukemia is characterized by the Philadelphia chromosome (BCR-ABL fusion)?
- Acute lymphoblastic leukemia
- Chronic myelogenous leukemia (Correct answer)
- Hairy cell leukemia
- Acute myeloid leukemia
Correct answer: Chronic myelogenous leukemia
Chronic myelogenous leukemia (CML) is defined by the t(9;22) translocation creating the BCR-ABL fusion gene.
ASCP Hematology 2
Sickle cell disease is caused by a substitution of which amino acid in the beta-globin chain?