Immuno Set 9 Flashcards
A 44-year-old school teacher who paints houses in the summer presents in early June with erythematous, indurated, and blistering lesions limited to his hands and forearms. The lesions typically appear each summer within several days of beginning to use painting products, including solvents and epoxy resins. He indicates that he does not wear protective gloves when working with these chemicals. The lesions disappear several weeks after he returns to his teaching position in the fall. Which of the following represents a likely step in the pathogenesis of this disease?
A. Activation of C1 B. Chemotaxis of neutrophils C. Induction of IgE antibodies D. Cell infiltration into the skin E. Immune complex deposition
D. Cell infiltration into the skin
A 44-year-old school teacher who paints houses in the summer presents in early June with erythematous, indurated, and blistering lesions limited to his hands and forearms. The lesions typically appear each summer within several days of beginning to use painting products, including solvents and epoxy resins. He indicates that he does not wear protective gloves when working with these chemicals. The lesions disappear several weeks after he returns to his teaching position in the fall. Which of the following test results would best fit the clinical findings in this case?
A. A positive skin test after 20 minutes with a dilute solution of epoxy resin
B. A positive skin patch test with a dilute solution of epoxy resin
C. Decreased serum levels of C1, C2, C3, and C4
D. A decreased CD4:CD8 ratio
E. Elevated serum tryptase
B. A positive skin patch test with a dilute solution of epoxy resin
Jim received penicillin for pneumonia several years ago and presented last week with what appeared to be an allergic reaction to the drug when it was taken for a sinus infection. The next day after beginning oral penicillin, Jim’s eyelids became puffy and his abdomen was covered with itchy, nearly confluent hives. After the administration of diphenhydramine and hydrocortisone his condition improved. Laboratory tests performed on his acute serum showed an elevated level of tryptase and decreased C1 and C3. A skin test with penicillin was negative. Which of the elements of this case suggests this reaction was caused by circulating IgG antibody- drug complexes, rather than IgE antibody to penicillin?
A. His plasma tryptase level was elevated.
B. His symptoms were corrected by administering antihistamines.
C. His C1 and C3 levels were decreased.
D. His skin lesions were pruritic (itchy).
E. He showed evidence of altered vascular permeability.
C. His C1 and C3 levels were decreased.
A 15-year-old female experiences flushing, pruritus, and urticaria, which began in the morning - during a class field trip to the local botanical garden. She is restless and uncomfortable and describes a sensation of “burning” and “pulling” in her skin. Which of the following best characterizes her condition?
A. Superantigen activation of CD4+ T cells
B. CD8+ T cell-mediated cytolysis of keratinocytes in the skin
C. CD4+ T cell-mediated delayed-type hypersensitivity to poison ivy
D. Complement activation by Ab-Ag immune complexes in the skin
E. Activation of IgE-coated mast cells leading to histamine release
E. Activation of IgE-coated mast cells leading to histamine release
All of the following are effector mechanisms of antibody-mediated disease EXEPT which of the following?
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 physiological ligands
E. FcR crosslinking
B. Fas-dependent apoptosis of cells
A 43-year-old woman sees her physician with complaints of anxiety, heat intolerance, arm weakness, tremor, and fatigue. Physical examination reveals tachycardia, diffuse thyroid enlargement, and abnormal protrusion of the eyeball. Laboratory tests indicate high serum thyroxine (T4) and triiodothyronine (T3) concentrations, with a high serum T3 to T4 ratio. The patient is treated with propylthiouracil and responses favorably. Which of the following is the underlying mechanism for patient’s condition?
A. Auto-Abs blockage of acetylcholine binding to acetylcholine receptor in the neuromuscular junction
B. Autoantibodies specific for thyroid-stimulating hormone (TSH) that blocks TSH binding to the TSH receptor
C. Autoantibody stimulation of TSH receptors
D. Autoantibody stimulation of thyroid hormone receptors
E. Autoreactive T cell-mediated damage to thyroid hormone-producing cells
C. Autoantibody stimulation of TSH receptors
A histological section of a kidney biopsy is notable for glomerular inflammation. Staining with fluorescent-labeled anti-IgG antibody revealed “lumpy-bumpy” staining pattern. Urinalysis is positive for moderate proteinuria and red cell casts. A chest X-ray shows pulmonary infiltrates. Which of the following is the most likely diagnosis?
A. Systemic lupus erythematous B. Grave’s disease C. Chronic allograft rejection D. Goodpasture’s syndrome E. Rheumatoid arthritis
A. Systemic lupus erythematous
Which type of hypersensitivity disease is caused by deposition of Ag-Ab complexes in the blood vessel walls?
A. Type I
B. Type II
C. Type III
D. Type IV
C. Type III
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 Ags
B. Immune complex-mediated diseases generally show systemic manifestation
C. Pathological features of immune complex diseases are determined by the cellular source of the Ag
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 the blood vessels and renal glomeruli.
C. Pathological features of immune complex diseases are determined by the cellular source of the Ag
Which of the following is NOT associated with immune complex deposition?
A. Arthus reaction B. Autoimmune hemolytic anemia C. Serum sickness D. Systemic lupus erythematous E. Poststreptococcal glomerulonephritis
B. Autoimmune hemolytic anemia
