NSG 530 EXAM 4 ADVANCED
PATHOPHYSIOLOGY ACTUAL EXAM |
150 QUESTIONS AND CORRECT
DETAILED ANSWERS WITH
RATIONALES | LATEST 2026-2027
VERSION |RATED A +
1. A 35-year-old patient presents with recurrent bacterial infections,
chronic diarrhea, and failure to thrive. Laboratory evaluation
reveals markedly decreased levels of all immunoglobulins. Which
type of immunodeficiency is most likely?
A. Selective IgA deficiency
B. Common variable immunodeficiency
C. Severe combined immunodeficiency (SCID)
D. Chronic granulomatous disease
Rationale:
SCID involves profound deficiencies in both humoral and cellular
immunity, leading to severe recurrent infections, failure to thrive, and
marked hypogammaglobulinemia. Selective IgA deficiency affects only
IgA, and CVID usually presents later with variable immunoglobulin
deficiencies.
2. A patient with a history of systemic lupus erythematosus (SLE)
develops hematuria and proteinuria. Which immunopathologic
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mechanism is primarily responsible for this renal involvement?
A. Type I hypersensitivity
B. Type III hypersensitivity
C. Type II hypersensitivity
D. Type IV hypersensitivity
Rationale:
Immune complex deposition (Type III hypersensitivity) in glomeruli
leads to inflammation, complement activation, and renal damage, as
seen in lupus nephritis. Type II involves antibody-mediated
cytotoxicity, Type I is IgE-mediated allergy, and Type IV is T-cell
mediated.
3. A 28-year-old man presents with fever, sore throat, and
lymphadenopathy. Monospot test is positive. Which virus is most
likely responsible?
A. Cytomegalovirus (CMV)
B. Epstein-Barr virus (EBV)
C. Herpes simplex virus (HSV)
D. Human immunodeficiency virus (HIV)
Rationale:
EBV infects B cells and epithelial cells, leading to infectious
mononucleosis characterized by fever, pharyngitis, and
lymphadenopathy. CMV can cause similar symptoms but typically has
a negative Monospot test. HSV causes localized lesions, and HIV
presents with chronic immunodeficiency.
4. A patient presents with a history of frequent abscesses and poor
wound healing. A nitroblue tetrazolium test is abnormal. Which
immune defect is most consistent with these findings?
A. X-linked agammaglobulinemia
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B. Complement deficiency
C. Severe combined immunodeficiency
D. Chronic granulomatous disease
Rationale:
Chronic granulomatous disease results from defective NADPH
oxidase in phagocytes, impairing the oxidative burst and leading to
recurrent bacterial and fungal infections. Nitroblue tetrazolium testing
detects this defect. X-linked agammaglobulinemia is B-cell mediated,
and complement deficiencies affect opsonization and MAC formation.
5. A patient develops hemolytic anemia after receiving penicillin.
Which immunologic mechanism is most likely involved?
A. Type I hypersensitivity
B. Type III hypersensitivity
C. Type II hypersensitivity
D. Type IV hypersensitivity
Rationale:
Type II hypersensitivity involves antibody-mediated cytotoxicity, where
drugs like penicillin bind to RBC surfaces and induce IgG-mediated
destruction, causing hemolytic anemia. Type I is IgE-mediated allergy,
Type III involves immune complexes, and Type IV is T-cell mediated.
6. A patient with HIV has a CD4+ T-cell count of 150 cells/mm³.
Which opportunistic infection is the patient most at risk for at this
stage?
A. Influenza
B. Pneumocystis jirovecii pneumonia (PCP)
C. Streptococcal pneumonia
D. Rhinovirus infection
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Rationale:
PCP is a hallmark opportunistic infection in patients with advanced
HIV and CD4 counts <200. Common viral infections like influenza
may occur at any immune status, but opportunistic pathogens like
PCP, toxoplasmosis, and Mycobacterium avium complex are linked to
severe immunodeficiency.
7. A 50-year-old man presents with fever, cough, and cavitary lung
lesions. Sputum cultures reveal acid-fast bacilli. Which immune
response is essential for containing this infection?
A. Humoral immunity (B cells)
B. Cell-mediated immunity (T cells, especially Th1)
C. Complement-mediated lysis
D. Eosinophil-mediated cytotoxicity
Rationale:
Mycobacterium tuberculosis is controlled primarily by cell-mediated
immunity. Th1 CD4+ cells activate macrophages to contain infection.
Humoral immunity plays a minimal role, while complement and
eosinophils are not central in TB defense.
8. A 5-year-old child presents with severe varicella (chickenpox)
infection. Genetic testing reveals a mutation in the IFN-γ receptor.
Which aspect of immunity is most compromised?
A. Humoral antibody response
B. Macrophage activation and intracellular pathogen defense
C. Mast cell degranulation
D. Complement-mediated lysis
Rationale:
IFN-γ is critical for activating macrophages to kill intracellular
pathogens like viruses and mycobacteria. Mutations impair