Medical Laboratory Technician Exam Medical Laboratory Technician Hematology and Coagulation Questions and Answers 2 — Questions and Answers
Question 1: A patient's blood smear shows hypersegmented neutrophils with macro-ovalocytes. Which vitamin deficiency is most likely responsible for these findings?
- Vitamin B12 or folate deficiency (Correct answer)
- Iron deficiency
- Vitamin C deficiency
- Vitamin K deficiency
Correct answer: Vitamin B12 or folate deficiency
Hypersegmented neutrophils and macro-ovalocytes are hallmark findings of megaloblastic anemia caused by vitamin B12 or folate deficiency.
Question 2: Which coagulation pathway is assessed by the activated partial thromboplastin time (aPTT)?
- Intrinsic and common pathways (Correct answer)
- Extrinsic and common pathways
- Intrinsic pathway only
- Platelet adhesion pathway
Correct answer: Intrinsic and common pathways
The aPTT evaluates factors in the intrinsic pathway (XII, XI, IX, VIII) and the common pathway (X, V, II, fibrinogen).
Question 3: What is the expected reticulocyte count pattern in a patient with aplastic anemia?
- Decreased reticulocyte count (Correct answer)
- Increased reticulocyte count
- Normal reticulocyte count
- Cyclically fluctuating reticulocyte count
Correct answer: Decreased reticulocyte count
Aplastic anemia involves bone marrow failure, resulting in decreased production of all cell lines including reticulocytes.
Question 4: A prolonged thrombin time (TT) that corrects with a mixing study most likely indicates which condition?
- Factor deficiency (Correct answer)
- Heparin contamination
- Fibrin degradation products
- Dysfibrinogenemia
Correct answer: Factor deficiency
Correction with a mixing study indicates a factor deficiency rather than an inhibitor, as the normal plasma supplies the missing factor.
Question 5: Which hemoglobin electrophoresis pattern is characteristic of sickle cell trait (HbAS)?
- HbA greater than HbS with normal HbA2 (Correct answer)
- HbS greater than HbA with elevated HbF
- HbS only with no HbA
- HbA only with elevated HbA2
Correct answer: HbA greater than HbS with normal HbA2
In sickle cell trait, HbA predominates over HbS (typically 55-60% HbA and 35-40% HbS) with normal HbA2 levels.
Question 6: What does a positive D-dimer result indicate in the context of coagulation testing?
- Active fibrinolysis of cross-linked fibrin (Correct answer)
- Primary fibrinogenolysis
- Platelet activation disorder
- Vitamin K deficiency
Correct answer: Active fibrinolysis of cross-linked fibrin
D-dimer is a specific degradation product of cross-linked fibrin, indicating that both thrombin generation and plasmin-mediated fibrinolysis have occurred.
Medical Laboratory Technician Exam Medical Laboratory Technician Hematology and Coagulation Questions and Answers 2
A patient's blood smear shows hypersegmented neutrophils with macro-ovalocytes.
Which vitamin deficiency is most likely responsible for these findings?