NR 507 Advanced Pathophysiology –
Week 1 EDAPT: Immune Response
Practice Questions & Explanations
Q1. Which hypersensitivity reaction is mediated by IgE?
Answer: Type I hypersensitivity.
Rationale: Type I (allergic/anaphylactic) reactions are IgE-mediated
and involve mast cell degranulation and histamine release.
Q2. A patient develops hemolytic anemia after receiving the wrong
blood type. Which hypersensitivity reaction is this?
Answer: Type II hypersensitivity.
Rationale: Type II involves antibody (IgG or IgM) binding to
antigens on cells → complement activation → cell lysis.
Q3. Which hypersensitivity type involves immune complexes
depositing in tissues?
Answer: Type III hypersensitivity.
Rationale: Immune complex–mediated reactions (e.g., lupus, serum
sickness) cause inflammation and tissue damage.
Q4. Which cells are primarily responsible for Type IV
hypersensitivity reactions?
,Answer: T lymphocytes (specifically CD4+ Th1 and CD8+ cytotoxic
T cells).
Rationale: Type IV is cell-mediated, not antibody-mediated (e.g., TB
skin test, contact dermatitis).
Q5. A patient with recurrent infections since infancy is found to have
a defect in B-cell function. What type of immune disorder is this?
Answer: Primary immunodeficiency.
Rationale: Primary (congenital) immunodeficiencies are genetic and
usually manifest in early life.
Q6. HIV primarily destroys which immune cells?
Answer: CD4+ T helper cells.
Rationale: HIV binds to CD4 receptors, leading to progressive
immunodeficiency (AIDS).
Q7. Which type of hypersensitivity reaction is most involved in
autoimmune diseases like rheumatoid arthritis?
Answer: Type III hypersensitivity.
Rationale: Autoantibodies form immune complexes that deposit in
joints, leading to inflammation.
Q8. What is the main difference between active and passive
immunity?
,Answer: Active = body produces its own antibodies; Passive =
antibodies are transferred.
Rationale: Active (e.g., vaccines) provides long-term protection;
passive (e.g., maternal antibodies, IVIG) is temporary.
Q9. A patient with a latex allergy experiences hives and
bronchospasm after exposure. Which immune mediator is
responsible?
Answer: Histamine.
Rationale: Mast cells release histamine, causing vasodilation,
bronchoconstriction, and itching in allergic reactions.
Q10. Which autoimmune disorder is characterized by destruction of
pancreatic beta cells?
Answer: Type 1 Diabetes Mellitus.
Rationale: An autoimmune T-cell–mediated response destroys
insulin-producing beta cells in the pancreas.
Q11. Which hypersensitivity type involves delayed onset (24–72
hours after exposure)?
Answer: Type IV hypersensitivity.
Rationale: Cell-mediated reactions (e.g., TB test, poison ivy) take
time for T-cell activation and cytokine release.
, Q12. Which immunoglobulin is elevated in allergic responses?
Answer: IgE.
Rationale: IgE binds to mast cells/basophils and triggers histamine
release upon allergen exposure.
Q13. Which hypersensitivity reaction explains post-streptococcal
glomerulonephritis?
Answer: Type III hypersensitivity.
Rationale: Immune complexes deposit in kidneys, causing
inflammation and tissue injury.
Q14. Which cytokine is critical for activating cytotoxic T cells?
Answer: Interleukin-2 (IL-2).
Rationale: IL-2, secreted by activated T helper cells, stimulates T-cell
proliferation and differentiation.
Q15. Which immune cells are the first responders to infection?
Answer: Neutrophils.
Rationale: Neutrophils are rapid responders, performing
phagocytosis at infection sites.
Q16. Which lab test best monitors HIV progression?
Week 1 EDAPT: Immune Response
Practice Questions & Explanations
Q1. Which hypersensitivity reaction is mediated by IgE?
Answer: Type I hypersensitivity.
Rationale: Type I (allergic/anaphylactic) reactions are IgE-mediated
and involve mast cell degranulation and histamine release.
Q2. A patient develops hemolytic anemia after receiving the wrong
blood type. Which hypersensitivity reaction is this?
Answer: Type II hypersensitivity.
Rationale: Type II involves antibody (IgG or IgM) binding to
antigens on cells → complement activation → cell lysis.
Q3. Which hypersensitivity type involves immune complexes
depositing in tissues?
Answer: Type III hypersensitivity.
Rationale: Immune complex–mediated reactions (e.g., lupus, serum
sickness) cause inflammation and tissue damage.
Q4. Which cells are primarily responsible for Type IV
hypersensitivity reactions?
,Answer: T lymphocytes (specifically CD4+ Th1 and CD8+ cytotoxic
T cells).
Rationale: Type IV is cell-mediated, not antibody-mediated (e.g., TB
skin test, contact dermatitis).
Q5. A patient with recurrent infections since infancy is found to have
a defect in B-cell function. What type of immune disorder is this?
Answer: Primary immunodeficiency.
Rationale: Primary (congenital) immunodeficiencies are genetic and
usually manifest in early life.
Q6. HIV primarily destroys which immune cells?
Answer: CD4+ T helper cells.
Rationale: HIV binds to CD4 receptors, leading to progressive
immunodeficiency (AIDS).
Q7. Which type of hypersensitivity reaction is most involved in
autoimmune diseases like rheumatoid arthritis?
Answer: Type III hypersensitivity.
Rationale: Autoantibodies form immune complexes that deposit in
joints, leading to inflammation.
Q8. What is the main difference between active and passive
immunity?
,Answer: Active = body produces its own antibodies; Passive =
antibodies are transferred.
Rationale: Active (e.g., vaccines) provides long-term protection;
passive (e.g., maternal antibodies, IVIG) is temporary.
Q9. A patient with a latex allergy experiences hives and
bronchospasm after exposure. Which immune mediator is
responsible?
Answer: Histamine.
Rationale: Mast cells release histamine, causing vasodilation,
bronchoconstriction, and itching in allergic reactions.
Q10. Which autoimmune disorder is characterized by destruction of
pancreatic beta cells?
Answer: Type 1 Diabetes Mellitus.
Rationale: An autoimmune T-cell–mediated response destroys
insulin-producing beta cells in the pancreas.
Q11. Which hypersensitivity type involves delayed onset (24–72
hours after exposure)?
Answer: Type IV hypersensitivity.
Rationale: Cell-mediated reactions (e.g., TB test, poison ivy) take
time for T-cell activation and cytokine release.
, Q12. Which immunoglobulin is elevated in allergic responses?
Answer: IgE.
Rationale: IgE binds to mast cells/basophils and triggers histamine
release upon allergen exposure.
Q13. Which hypersensitivity reaction explains post-streptococcal
glomerulonephritis?
Answer: Type III hypersensitivity.
Rationale: Immune complexes deposit in kidneys, causing
inflammation and tissue injury.
Q14. Which cytokine is critical for activating cytotoxic T cells?
Answer: Interleukin-2 (IL-2).
Rationale: IL-2, secreted by activated T helper cells, stimulates T-cell
proliferation and differentiation.
Q15. Which immune cells are the first responders to infection?
Answer: Neutrophils.
Rationale: Neutrophils are rapid responders, performing
phagocytosis at infection sites.
Q16. Which lab test best monitors HIV progression?
