NEET-PG 2015 - Pathology Practice Questions

Q: Which type of artery is most commonly involved in PAN?

Muscular. ***Muscular*** - **Polyarteritis nodosa (PAN)** predominantly affects **medium to small-sized muscular arteries**, leading to inflammation, necrosis, and microaneurysms [1]. - This involvement often causes **organ ischemia** and symptoms related to the affected organs, such as the kidneys, gastrointestinal tract, and skin [1]. *Elastic* - **Elastic arteries**, such as the aorta and its major branches, are typically spared in PAN due to their larger size and distinct histological structure. - Diseases like **Takayasu arteritis** or **Giant cell arteritis** are more commonly associated with vasculitis affecting large elastic arteries. *Arterioles* - While arterioles can be affected in various forms of vasculitis, they are not the primary target in classic PAN. - Involvement of arterioles is more characteristic of **microscopic polyangiitis** or **Churg-Strauss syndrome** [2]. *Capillaries* - **Capillaries** are the smallest blood vessels, and their involvement is rare in PAN. - Conditions like **Henoch-Schönlein purpura** or some drug-induced vasculitides more typically affect capillaries, often resulting in palpable purpura [2].

Q: Which of the following statements is true regarding the Duffy Fy(a-b-) blood group?

lacks Fy(b) antigen. ***lacks Fy(b) antigen*** - The **Duffy Fy(a-b-)** phenotype indicates absence of both Fy a and Fy b antigens on red blood cells. - Since the phenotype is **Fy(a-b-)**, it definitively lacks the **Fy b antigen** (indicated by the "b-" notation). - This phenotype is common in people of **African descent** and confers natural **resistance to Plasmodium vivax malaria**, as these antigens serve as receptors for the parasite to enter RBCs. *lacks H- antigen* - The **H antigen** belongs to the **H/h blood group system** and is a precursor to A and B antigens in the ABO system. - The absence of H antigen (Bombay phenotype - Oh) is completely **unrelated to the Duffy blood group system**. - Duffy antigens are on the **DARC (Duffy Antigen Receptor for Chemokines)** protein, distinct from the H antigen. *lacks A-antigen* - The **A antigen** is part of the **ABO blood group system** and defines blood types A and AB. - The Duffy blood group system is **genetically and structurally independent** from the ABO system. - Having Fy(a-b-) phenotype does not affect A antigen expression. *All of the options* - This is incorrect because the Duffy Fy(a-b-) phenotype **specifically refers only to the absence of Duffy antigens** (Fy a and Fy b ). - It has **no relationship** with A, B, or H antigens, which belong to different blood group systems controlled by different genes on different chromosomes.

Q: What is a distinguishing feature of reticulocytes?

Presence of residual RNA and ribosomes. ***Presence of residual RNA and ribosomes*** - This is the **defining and most distinguishing feature** of reticulocytes that differentiates them from mature red blood cells. - Reticulocytes contain residual **ribosomal RNA** and other organelles that are lost when they mature into erythrocytes. - This residual RNA forms a **reticular (network-like) pattern** when stained with supravital stains like **new methylene blue** or **brilliant cresyl blue**, which is the basis for their name and identification. - The presence of RNA allows for **reticulocyte counting**, an important marker of bone marrow erythropoietic activity. *Slightly larger in size than RBCs* - While reticulocytes may be slightly larger (polychromatophilic appearance), size variation is **not specific** and overlaps significantly with mature RBCs. - Size is not a reliable distinguishing feature and is not used for identification or counting. *Mature in bone marrow* - Reticulocytes are **released from the bone marrow** as immature red cells and complete their maturation in the **peripheral circulation** over 24-48 hours. - They do not fully mature in the bone marrow; their presence in peripheral blood is normal. *Constitute approximately 1% of the red cells* - Normal reticulocyte count is **0.5-2%** (or approximately 1%) of total red blood cells in healthy adults. - This is a **population characteristic** indicating normal erythropoietic activity, not a distinguishing cellular feature.

Q: Which antibody is primarily associated with warm autoimmune hemolytic anemia (AIHA)?

IgG. ***IgG*** - **Warm autoimmune hemolytic anemia (AIHA)** is primarily associated with **IgG antibodies**, which mediate hemolysis at body temperature [1]. - IgG antibodies typically bind to red blood cells and lead to their destruction by the **reticuloendothelial system** [1]. *IgM* - Often involved in **cold agglutinin disease**, not warm AIHA, as it primarily reacts at lower temperatures [2]. - Usually results in **hemolysis** in peripheral areas, like the extremities, rather than at normal body temperature [2]. *IgD* - Known primarily as a marker on **B cells**, it plays a minimal role in hemolytic anemia and is not involved in antibody-mediated hemolysis. - Lack of significant **serological presence** in autoimmune hemolytic processes makes it an unlikely candidate. *IgE* - Primarily associated with **allergic reactions** and parasitic infections rather than autoimmune hemolytic conditions [2]. - Does not typically participate in **hemolysis** or bind to red blood cells in AIHA.

Q: Osmotic fragility test is commonly used for which of the following conditions?

Hereditary spherocytosis. ***Hereditary spherocytosis*** - The **osmotic fragility test** helps in diagnosing hereditary spherocytosis, where **spherical red blood cells** are more prone to hemolysis in hypotonic solutions [1][2]. - This condition is characterized by **spherocytes** (abnormally shaped RBCs) leading to increased osmotic fragility [1][3]. *Megaloblastic anemia* - Megaloblastic anemia is primarily associated with **deficiencies in B12 or folate**, affecting the size and maturation of red blood cells, not their osmotic fragility. - The diagnosis focuses on **serum vitamin levels** and **bone marrow examination** rather than osmotic fragility. *Iron deficiency anemia* - Iron deficiency anemia features **microcytic** and **hypochromic RBCs**, and its diagnosis relies on **iron studies**, not osmotic fragility tests. - The osmotic fragility test does not reveal significant changes in red blood cells for this condition. *Aplastic anemia* - Aplastic anemia involves **pancytopenia** due to bone marrow failure and does not typically show altered osmotic fragility. - The diagnosis is confirmed through **bone marrow biopsy**, not by assessing osmotic fragility. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 597-598. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 640-641. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, p. 638.

Q: Which of the following findings is diagnostic of iron deficiency anemia?

Increased TIBC, decreased serum ferritin. ***Increased TIBC, decreased serum ferritin*** - **Iron deficiency anemia** is characterized by depleted iron stores, leading to a **decreased serum ferritin** level, which is the most sensitive and specific marker for iron deficiency [4]. - In response to low iron stores, the body upregulates iron absorption and transport mechanisms, resulting in an **increased Total Iron Binding Capacity (TIBC)**, as there are more transferrin molecules available to bind iron [1]. *Decreased TIBC, decreased serum ferritin* - While a **decreased serum ferritin** is consistent with iron deficiency, a **decreased TIBC** is more indicative of **anemia of chronic disease** [1], where the body sequesters iron, leading to reduced iron availability for binding. - In **anemia of chronic disease**, both ferritin (an acute phase reactant) and TIBC can be reduced due to the inflammatory state [1], [2]. *Increased TIBC, increased serum ferritin* - An **increased TIBC** is seen in iron deficiency, but an **increased serum ferritin** indicates adequate or even **overloaded iron stores**, which contradicts the diagnosis of iron deficiency anemia. - High ferritin levels can be seen in conditions like **hemochromatosis** (iron overload) or **inflammation**, where ferritin acts as an acute phase reactant [5]. *Decreased TIBC, increased serum ferritin* - This combination is typical of **anemia of chronic disease**, where inflammation causes **increased serum ferritin** (as an acute phase reactant) and a **decreased TIBC** due to reduced production of transferrin [1]. - In this type of anemia, iron is often trapped within macrophages, making it unavailable for erythropoiesis despite seemingly normal or elevated stores [3].

Q: What does ristocetin testing indicate in von Willebrand disease?

Decreased agglutination. ***Decreased agglutination*** - In von Willebrand disease, **ristocetin induces less agglutination** due to a deficiency or dysfunction of von Willebrand factor. - This results in **impaired platelet adhesion** [1], crucial for effective hemostasis. *Increased agglutination* - Would suggest an increased platelet interaction, which is **not characteristic of von Willebrand disease**. - It can occur in conditions with enhanced von Willebrand factor, unlike in this case. *No agglutination* - Suggests complete lack of platelet interaction, which is **not typical** in von Willebrand disease. - There is often some level of interaction, albeit reduced, not a total absence of agglutination. *Normal agglutination* - Indicates no abnormalities, which **contradicts the known pathology** of von Willebrand disease. - Patients typically demonstrate decreased levels of agglutination, not normal findings in this test.

Q: Shelf life of platelets in a blood bank is

5 days. **5 days** - Platelets stored at **room temperature (20-24°C)** have a limited shelf life due to the risk of bacterial contamination and metabolic changes. - This short storage period ensures the **viability and function** of platelets for transfusion. *7 days* - A 7-day shelf life was initially proposed but was not widely adopted due to concerns about increased **bacterial growth** and the practical challenges of extended storage at room temperature. - The risk of **bacterial sepsis** significantly increases with longer room temperature storage. *10 days* - This duration is beyond the currently accepted shelf life for platelets, leading to an unacceptably high risk of **bacterial contamination** and reduced therapeutic efficacy. - Storing platelets for 10 days would likely result in an increased incidence of **transfusion-associated sepsis**. *21 days* - A shelf life of 21 days is typical for **red blood cells** when stored at 1-6°C with specific anticoagulants, but it is far too long for platelets. - Platelets stored for this duration at room temperature would be significantly **non-viable** and pose a severe risk of bacterial infection.

Q: Which antigen is tested in routine Rh typing?

D antigen. ***D antigen*** - Routine Rh typing specifically tests for the **D antigen**, which determines the Rh status of an individual as Rh-positive or Rh-negative [1]. - The presence of the **D antigen** is crucial for blood transfusions and pregnancy management [1]. *A antigen* - The **A antigen** is tested in the context of the ABO blood group system, not specifically for Rh typing. - It does not provide information regarding the Rh factor which is critical in blood compatibility. *C antigen* - Similar to the **A antigen**, the **C antigen** is part of the broader Rh system but is not routinely assessed in standard Rh typing. - Its testing is typically reserved for specific clinical scenarios involving Rh incompatibility. *B antigen* - The **B antigen** pertains to the ABO blood group and does not relate to the Rh factor or routine Rh typing. - Rh typing is solely focused on the **presence of the D antigen** to determine the Rh status. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 627-628.

Q: Diabetic foot is associated with following type of gangrene -

Wet gangrene. ***Wet gangrene*** - Diabetic foot commonly leads to **ischemia** and **infection** [1], resulting in wet gangrene characterized by moist, necrotic tissue. - This type of gangrene is associated with **rapid progression** and can result in systemic toxicity, making prompt treatment essential. *Fournier's gangrene* - This type of gangrene specifically affects the **perineal** region and is not directly associated with diabetic foot. - It usually arises from infections related to **perineal trauma** or surgical procedures. *Gas gangrene* - Caused by **Clostridium** species and typically follows a traumatic injury or surgical procedure, not specifically related to diabetes. - Presents with **crepitus** and rapid systemic symptoms, different from the chronic nature of diabetic ulcers. *Dry gangrene* - Associated with **chronic ischemia** and necrosis, it occurs in conditions like peripheral arterial disease, not primarily with infections seen in diabetic foot [1]. - It usually develops gradually without the sudden onset of symptoms characteristic of wet gangrene.

Question 1

Which type of artery is most commonly involved in PAN?

Accepted Answer

Muscular

Answer

Capillaries

Answer

Elastic

Answer

Arterioles

Question 2

Which of the following statements is true regarding the Duffy Fy(a-b-) blood group?

Accepted Answer

lacks Fy(b) antigen

Answer

lacks H- antigen

Answer

lacks A-antigen

Answer

All of the options

Question 3

What is a distinguishing feature of reticulocytes?

Accepted Answer

Presence of residual RNA and ribosomes

Answer

Slightly larger in size than RBCs

Answer

Mature in bone marrow

Answer

Constitute approximately 1% of the red cells

Question 4

Which antibody is primarily associated with warm autoimmune hemolytic anemia (AIHA)?

Accepted Answer

IgG

Answer

IgE

Answer

IgM

Answer

IgD

Question 5

Osmotic fragility test is commonly used for which of the following conditions?

Accepted Answer

Hereditary spherocytosis

Answer

Megaloblastic anemia

Answer

Aplastic anemia

Answer

Iron deficiency anemia

Question 6

Which of the following findings is diagnostic of iron deficiency anemia?

Accepted Answer

Increased TIBC, decreased serum ferritin

Answer

Decreased TIBC, decreased serum ferritin

Answer

Increased TIBC, increased serum ferritin

Answer

Decreased TIBC, increased serum ferritin

Question 7

What does ristocetin testing indicate in von Willebrand disease?

Accepted Answer

Decreased agglutination

Answer

Normal agglutination

Answer

Increased agglutination

Answer

No agglutination

Question 8

Shelf life of platelets in a blood bank is

Accepted Answer

5 days

Answer

7 days

Answer

10 days

Answer

21 days

Question 9

Which antigen is tested in routine Rh typing?

Accepted Answer

D antigen

Answer

C antigen

Answer

A antigen

Answer

B antigen

Question 10

Diabetic foot is associated with following type of gangrene -

Accepted Answer

Wet gangrene

Answer

Dry gangrene

Answer

Gas gangrene

Answer

Fournier's gangrene

NEET-PG 2015 — Pathology