Deck 11: Hypersensitivity

Question 1

An 8-year-old boy from the intermountain region of the United States is brought to the pediatrician with fever, rash, and pain in his knees and ankles. Pericarditis is evident on auscultation, and echocardiography confirms mitral valve regurgitation. Three weeks before this episode, the patient had experienced a sore throat but had not received medical attention. High titers of antistreptococcal antibodies are present in the serum. This child's disease is a result of which one of the following phenomena?

A)Clonal anergy
B)Peripheral tolerance
C)Epitope spreading
D)Central tolerance
E)Molecular mimicry

Answer 1

Molecular mimicry

Question 2

Which of the following is NOT associated with increased relative risk of developing systemic lupus erythematosus?

A)Female gender
B)Deficiency in complement protein C2
C)African-American ethnicity
D)Presence of HLA-DR3
E)Defect in B cell maturation

Answer 2

Defect in B cell maturation

Question 3

Which of the following is a common cause of hypersensitivity diseases?

A)Failure of lymphocyte maturation
B)Treatment with corticosteroids
C)Disseminated cancer
D)Failure of self-tolerance
E)Malnutrition

Answer 3

Failure of self-tolerance

Question 4

Which of the following statements about immune complex-mediated diseases is NOT true?

A)Immune complexes may contain antibodies bound to either self or foreign antigens.
B)Immune complex-mediated diseases generally show systemic manifestations.
C)Pathologic features of immune complex diseases are determined by the cellular source of the antigen.
D)Small complexes are deposited in vessels more than large complexes, which are usually efficiently phagocytosed.
E)Complexes containing cationic antigens are more likely to produce severe, long-lasting injury by depositing in blood vessels and renal glomeruli.

Question 5

All of the following are effector mechanisms of antibody-mediated disease EXCEPT:

A)Opsonization and phagocytosis of cells
B)Fas-dependent apoptosis of cells
C)Complement- and Fc receptor-mediated inflammation and tissue injury
D)Antibody stimulation of cell surface receptors in the absence of the physiologic ligands
E)FcϬR crosslinking

Question 6

A 26-year-old African-American woman visits her physician because of a prominent rash over her nose and cheeks, which she first noticed following her return from a vacation in Jamaica. She also complains of fever, fatigue, weight loss, and joint pain over the last several months. Serologic tests are conclusive for systemic lupus erythematosus (SLE), an autoimmune disease that can manifest clinically with rashes, arthritis, glomerulonephritis, hemolytic anemia, thrombocytopenia (low platelet count), and central nervous system involvement. The principal diagnostic test result specific for this condition is a high titer of autoantibodies against which of the following?

A)Glomerular basement membrane
B)Rh blood group antigen
C)Myelin
D)Double-stranded DNA
E)IgG

Question 7

In which of the following disorders is the underlying pathogenic mechanism NOT due to antibody-mediated damage to cells or tissues?

A)Pernicious anemia
B)Autoimmune hemolytic anemia
C)Pemphigus vulgaris
D)Acute rheumatic fever
E)Hyperacute allograft rejection

Question 8

Which type of hypersensitivity disease is caused by deposition of antigen-antibody complexes in blood vessel walls?

A)Type I
B)Type II
C)Type III
D)Type IV
E)Type V

Question 9

Which one of the following statements concerning autoimmune disease is true?

A)Autoimmunity manifests as organ-specific, not systemic, disease.
B)Infectious microorganisms are frequently present in autoimmune lesions.
C)Effector mechanisms in autoimmunity include circulating autoantibodies, immune complexes, and autoreactive T lymphocytes.
D)Among the genes associated with autoimmunity, associations are particularly prevalent with class I MHC genes.
E)Many autoimmune diseases show higher incidence in males than in females.

Question 10

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of a human organ-specific autoimmune disease mediated by T lymphocytes. In EAE, rodents are immunized with proteins found in the myelin sheath of central nervous system neurons. EAE is a model for which of the following human diseases?

A)Rheumatoid arthritis
B)Autoimmune myocarditis
C)Systemic lupus erythematosus
D)Diabetes mellitus type 1 (insulin-dependent)
E)Multiple sclerosis

Question 11

Which of the following conditions is NOT associated with immune complex deposition?

A)Arthus reaction
B)Autoimmune hemolytic anemia
C)Serum sickness
D)Systemic lupus erythematosus
E)Poststreptococcal glomerulonephritis

Question 12

Individuals with the class I HLA-B27 allele have a 90-fold greater chance of developing which of the following inflammatory diseases, relative to HLA-B27-negative individuals?

A)Rheumatoid arthritis
B)Ankylosing spondylitis
C)Pemphigus vulgaris
D)Diabetes mellitus type 1 (insulin dependent)
E)Multiple sclerosis

Question 13

A 14-year-old boy is brought to the pediatrician's office in mid summer because of an itchy, blistering rash on his calves and forearms. The rash developed 24 hours after he returned from a weekend Boy Scout camping trip. The pediatrician suspects the lesion is caused by poison ivy. If the doctor is correct, which one of the following is NOT a prominent component in the immunologic mechanisms causing the skin lesions?

A)T cells
B)IgE-coated mast cells
C)Interferon-ƴ
D)Endothelial adhesion molecules
E)Chemokines

Question 14

Which of the following would NOT be a likely therapy for treating autoimmune diseases?

A)Corticosteroids
B)Small molecule inhibitor of VLA-4
C)Cyclosporine
D)CTLA-4 antagonist
E)Plasmapheresis