MLPAO Hematology and Coagulation Fundamentals 2 — Questions and Answers
Question 1: What does an elevated reticulocyte count indicate?
- Bone marrow failure
- Increased red blood cell production (erythropoietic response) (Correct answer)
- Iron deficiency
- Chronic disease
Correct answer: Increased red blood cell production (erythropoietic response)
An elevated reticulocyte count indicates increased erythropoietic activity in the bone marrow, typically in response to anemia, blood loss, or hemolysis. Reticulocytes are immature red blood cells that still contain residual RNA and mature in the circulation within 1-2 days.
Question 2: Which stain is used to identify iron stores in bone marrow aspirates?
- Wright-Giemsa stain
- Prussian blue (Perls) stain (Correct answer)
- Sudan black B stain
- Periodic acid-Schiff (PAS) stain
Correct answer: Prussian blue (Perls) stain
Prussian blue (Perls) stain reacts with ferric iron (Fe3+) in hemosiderin to produce a blue-green color. It is used to assess iron stores in bone marrow macrophages and to identify sideroblasts (erythroblasts containing iron granules). Absent stainable iron confirms iron deficiency.
Question 3: What is the role of erythropoietin (EPO) in hematopoiesis?
- Stimulates white blood cell production
- Stimulates red blood cell production in response to hypoxia (Correct answer)
- Stimulates platelet production
- Inhibits bone marrow stem cell differentiation
Correct answer: Stimulates red blood cell production in response to hypoxia
Erythropoietin is a glycoprotein hormone produced primarily by the kidneys in response to tissue hypoxia. It stimulates erythroid progenitor cells in the bone marrow to proliferate and differentiate into mature red blood cells. Chronic kidney disease reduces EPO production, causing anemia.
Question 4: Which white blood cell type is most numerous in normal adult peripheral blood?
- Lymphocytes
- Monocytes
- Neutrophils (Correct answer)
- Eosinophils
Correct answer: Neutrophils
Neutrophils are the most abundant white blood cell type in normal adult blood, comprising 40-70% of the total WBC count. They are the primary phagocytic cells of the innate immune system and are the first responders to bacterial infections.
Question 5: What does a 'left shift' in the white blood cell differential indicate?
- An increase in mature lymphocytes
- An increase in immature granulocytes (bands and metamyelocytes) indicating active infection (Correct answer)
- A decrease in all white blood cell types
- An increase in eosinophils
Correct answer: An increase in immature granulocytes (bands and metamyelocytes) indicating active infection
A left shift refers to an increase in immature granulocytes (particularly band neutrophils, but also metamyelocytes and myelocytes) in peripheral blood. This indicates the bone marrow is releasing cells prematurely in response to increased demand, typically from bacterial infection or inflammation.
Question 6: Which hereditary condition causes sickle-shaped red blood cells under conditions of low oxygen?
- Hereditary spherocytosis
- Sickle cell disease (HbSS) (Correct answer)
- Glucose-6-phosphate dehydrogenase deficiency
- Thalassemia major
Correct answer: Sickle cell disease (HbSS)
Sickle cell disease is caused by a point mutation in the beta-globin gene (Glu6Val) producing hemoglobin S. Under low oxygen conditions, HbS polymerizes, causing the characteristic sickle shape. This leads to vaso-occlusion, chronic hemolytic anemia, and organ damage.
MLPAO Hematology and Coagulation Fundamentals 2
What does an elevated reticulocyte count indicate?