ABPath Clinical Pathology 1 — Questions and Answers

Question 1: Which of the following is the most common cause of acquired hemolytic anemia?

Hereditary spherocytosis
Autoimmune hemolytic anemia (Correct answer)
Sickle cell disease
Thalassemia

Correct answer: Autoimmune hemolytic anemia

Acquired hemolytic anemias are conditions where red blood cells are prematurely destroyed due to factors outside of inherited defects. Autoimmune hemolytic anemia (AIHA) is the most common acquired form, where the body's immune system mistakenly produces antibodies that target and destroy its own red blood cells. This immune-mediated destruction can be primary or secondary to other diseases.

Question 2: Which laboratory test is primarily used to assess liver function?

Complete blood count (CBC)
Liver function tests (LFTs) (Correct answer)
Coagulation profile
Arterial blood gases (ABG)

Correct answer: Liver function tests (LFTs)

Liver function tests (LFTs) are a panel of blood tests specifically designed to assess the health and function of the liver. These tests measure various enzymes (like ALT, AST, ALP, GGT) and proteins (like albumin, bilirubin) that are produced by the liver or are released when liver cells are damaged. They provide crucial information about liver inflammation, damage, and synthetic capacity.

Question 3: A patient presents with a high white blood cell count. Which condition is most likely?

Acute leukemia
Chronic myelogenous leukemia (Correct answer)
Lymphoma
Acute viral infection

Correct answer: Chronic myelogenous leukemia

While acute leukemia can present with a high WBC count, chronic myelogenous leukemia (CML) is classically associated with extremely high, often markedly elevated, white blood cell counts, sometimes exceeding 100,000 cells/µL. This is due to the uncontrolled proliferation of mature and immature myeloid cells, particularly neutrophils, in the bone marrow and peripheral blood.

Question 4: What is the primary function of platelets in the blood?

Oxygen transport
Immune response
Blood clotting (Correct answer)
Nutrient transport

Correct answer: Blood clotting

Platelets, also known as thrombocytes, are small, anucleated cell fragments crucial for hemostasis, the process of stopping bleeding. Their primary function is to form a platelet plug at sites of vascular injury and to provide a surface for the activation of coagulation factors, ultimately leading to the formation of a stable fibrin clot.

Question 5: Which of the following tests is most appropriate for diagnosing tuberculosis (TB)?

Chest X-ray
Sputum smear for acid-fast bacilli (Correct answer)
Complete blood count (CBC)
Liver function tests (LFTs)

Correct answer: Sputum smear for acid-fast bacilli

While a chest X-ray can suggest TB, the definitive diagnosis of active pulmonary tuberculosis relies on identifying the causative organism, Mycobacterium tuberculosis. A sputum smear for acid-fast bacilli (AFB) directly visualizes these bacteria under a microscope, and a sputum culture provides confirmation and drug susceptibility testing, making it the most appropriate diagnostic test.

Question 6: In which condition is a "shift to the left" observed in the white blood cell count?

Acute inflammation (Correct answer)
Chronic inflammation
Viral infection
Iron-deficiency anemia

Correct answer: Acute inflammation

A 'shift to the left' refers to an increase in the proportion of immature neutrophils (band forms or metamyelocytes) in the peripheral blood. This phenomenon is a classic indicator of acute inflammation or infection, where the bone marrow is rapidly producing and releasing neutrophils to combat the insult, often before they have fully matured.

Question 7: What does a positive Coombs test indicate?

Hemolytic anemia (Correct answer)
Iron-deficiency anemia
Sickle cell disease
Vitamin B12 deficiency

Correct answer: Hemolytic anemia

A positive Coombs test (direct antiglobulin test) indicates the presence of antibodies or complement components bound to the surface of red blood cells. This binding marks the red blood cells for destruction, leading to hemolytic anemia. It is a key diagnostic test for immune-mediated hemolytic anemias, such as autoimmune hemolytic anemia or hemolytic disease of the newborn.

Question 8: Which of the following conditions is associated with a high erythrocyte sedimentation rate (ESR)?

Iron-deficiency anemia
Rheumatoid arthritis (Correct answer)
Sickle cell anemia
Chronic dehydration

Correct answer: Rheumatoid arthritis

The erythrocyte sedimentation rate (ESR) is a non-specific marker of inflammation. It measures the rate at which red blood cells settle in a tube of blood over a specific time. In inflammatory conditions like rheumatoid arthritis, increased levels of acute phase proteins (e.g., fibrinogen) cause red blood cells to aggregate and settle faster, resulting in an elevated ESR.

Question 9: What is the primary purpose of a bone marrow biopsy?

To diagnose anemia
To assess the bone marrow's ability to produce blood cells (Correct answer)
To evaluate liver function
To assess kidney function

Correct answer: To assess the bone marrow's ability to produce blood cells

A bone marrow biopsy is a diagnostic procedure that involves taking a sample of bone marrow, typically from the hip bone. Its primary purpose is to evaluate the cellularity, morphology, and maturation of blood cell precursors within the marrow, thereby assessing its ability to produce red blood cells, white blood cells, and platelets. This is crucial for diagnosing various hematologic disorders, including leukemias, lymphomas, and anemias.

ABPath Clinical Pathology 1

Which of the following is the most common cause of acquired hemolytic anemia?