CLS CLS Hematology and Coagulation 2 — Questions and Answers
Question 1: Which stain is routinely used to identify malaria parasites on a peripheral blood smear?
- Gram stain
- Wright-Giemsa stain (Correct answer)
- Ziehl-Neelsen stain
- India ink stain
Correct answer: Wright-Giemsa stain
Wright-Giemsa stain is the standard stain for peripheral blood smear examination, including identification of intraerythrocytic malaria parasites.
Question 2: Sickle cell disease results from a mutation in which protein?
- Albumin
- Fibrinogen
- Hemoglobin (Correct answer)
- Myoglobin
Correct answer: Hemoglobin
Sickle cell disease is caused by a point mutation (Glu→Val) in the beta-globin gene, producing abnormal hemoglobin S.
Question 3: The aPTT (activated Partial Thromboplastin Time) is primarily used to assess which pathway and monitor which therapy?
- Extrinsic pathway; warfarin monitoring
- Intrinsic and common pathways; heparin monitoring (Correct answer)
- Platelet function; aspirin monitoring
- Fibrinolysis; tPA monitoring
Correct answer: Intrinsic and common pathways; heparin monitoring
aPTT evaluates the intrinsic and common coagulation pathways and is the primary test used to monitor unfractionated heparin therapy.
Question 4: Hemolytic Uremic Syndrome (HUS) is classically characterized by which triad?
- Microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure (Correct answer)
- Fever, thrombocytopenia, and neurological symptoms
- Hemolytic anemia, jaundice, and splenomegaly
- DIC, sepsis, and organ failure
Correct answer: Microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure
HUS presents with the classic triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure, often following E. coli O157:H7 infection.
Question 5: In a complete blood count, what does a high RDW (Red Cell Distribution Width) indicate?
- Increased red cell density
- Greater variation in red cell size (anisocytosis) (Correct answer)
- Elevated reticulocyte count
- Increased red cell fragility
Correct answer: Greater variation in red cell size (anisocytosis)
RDW quantifies variation in red blood cell size (anisocytosis); an elevated RDW indicates a heterogeneous population of red cells.
Question 6: Which vitamin is essential for the gamma-carboxylation and activation of clotting Factors II, VII, IX, and X?
- Vitamin A
- Vitamin B12
- Vitamin C
- Vitamin K (Correct answer)
Correct answer: Vitamin K
Vitamin K is required for gamma-carboxylation of Factors II, VII, IX, and X, enabling them to bind calcium and become functional.
CLS CLS Hematology and Coagulation 2
Which stain is routinely used to identify malaria parasites on a peripheral blood smear?