3. Toll-like receptors function in which one of the following?
A. Regulation of B-cell activation by antigen binding
B. Activation of the complement pathway
C. Recognition of microorganisms by the innate immune system
D. Activation of immunoglobulin chain switching
E. Inhibition of eosinophils
4. Which one of the following is an advantage of killed viral vaccines compared with live viral vaccines?
A. Killed viral vaccines produce a CD8 cytotoxic T-cell response
B. Killed viral vaccines can be given by the natural route of infection and induce an immunoglobulin G and A response
C. Killed viral vaccines often confer life-long protection
D. Killed viral vaccines do not revert to virulence
E. Killed viral vaccines can be given pre-exposure to disease-causing agents
5. Which one of the following is the main difference between cytotoxic (type II) and immune complex (type III) hypersensitivity?
A. Distribution of antigen–antibody complexes
B. Involvement of T cells
C. Involvement of complement
D. Antibody isotype
E. Difference in triggers
6. Which one of the following correctly describes immunoglobulin A (IgA) in humans?
A. It is the rarest immunoglobulin isotype
B. The two subclasses of IgA, IgA1 and IgA2, differ in their light chains
C. IgA2 is present more abundantly than IgA1 in the airways
D. Secretory IgA can reduce the motility of Salmonella species, thus affecting the bacterial virulence
E. IgA2 is the predominant subclass in the serum
7. Which one of the following describes the involvement of human natural killer (NK) cells in innate immunity?
A. NK cells are activated directly by macrophages
B. NK cells express antigen-specific receptors
C. NK cells contribute to the delayed T-cell response following infection
D. NK cells do not mediate antibody-dependent cellular cytotoxicity
E. NK cells are found only in the lymph nodes
8. A 24-year-old man is stung by a bee and experiences respiratory distress within minutes and lapses into unconsciousness. This reaction is probably mediated by:
A. IgG antibody
B. IgE antibody
C. IgM antibody
D. Complement
E. Sensitised T cells
9. Which one of the following is a mechanism in the development of immune tolerance?
A. Clonal amplification of B cells in the thymus
B. Failure of B cells bearing low-affinity receptors to recognise self-antigens in the thymus
C. T cells in the thymus with high affinity for self-antigen undergo positive selection
D. Regulatory T cells actively activate an immune response to an antigen
E. Acquisition of anergy after T-cell receptor ligation without co-stimulation
10. A 56-year-old bee-farmer was admitted after an anaphylactic reaction to bee stings. He underwent immunotherapy/desensitisation to prevent future adverse reactions associated with bee stings. Which one of the following mechanisms explains the principle of immunotherapy?
A. Reduces allergen-specific IgE
B. Acts by induction of ‘blocking’ IgG antibodies
C. Works by altering T-cell reactivity to specific antigen, which in turn causes a reduction in release of pro-allergic/inflammatory cytokines
D. Works by inactivating B cells, which then alters T-cell reactivity to the specific antigen
E. Acts by blocking the antigen-presenting cells directly, so the foreign antigen is not detected by the immune system of the patient
11. Interferon-gamma is produced by:
A. Type 1 helper T cells
B. Type 2 helper T cells
C. B lymphocytes
D. Plasma cells
E. Eosinophils
Theme: Cytokines and immune cells (for Questions 12 and 13)
A. Neutrophils
B. Eosinophils
C. B lymphocytes
D. T lymphocytes
E. Macrophages
F. Dendritic cells
G. Natural killer cells
H. Plasma cells
12. Which cell is the main source of interleukin-1?
13. Which cell is the main source of interleukin-2?
Clinical
14. A 24-year-old man with a history of hereditary angio-oedema (HAE) presents with acute breathlessness and on examination is found to have laryngeal, pharyngeal and tongue oedema. In addition to securing his airway, which drug should be administered urgently?
A. Intravenous methylprednisolone
B. Intravenous frusemide
C. Anti-histamine
D. Fresh frozen plasma (FFP)
E. Nebulised salbutamol
15. A 20-year-old woman presents with dyspnoea, angio-oedema, urticaria and hypotension after eating shellfish. She is successfully treated with epinephrine (adrenaline), anti-histamines, corticosteroid and intravenous fluids. She has a history of asthma. She takes inhaled beclomethasone. Radioallergosorbent (RAST) testing reveals the presence of shellfish-specific IgE. Which one of the following statements regarding this patient’s condition is the most accurate?
A. This allergy is likely to disappear in a few years
B. She should avoid other highly allergenic foods, such as peanuts and tree nuts
C. She is at high risk for developing a more severe anaphylactic reaction in the future if she ingests shellfish
D. She had a type II hypersensitivity reaction
E. She had a type IV hypersensitivity reaction
16. A 30-year-old Aboriginal woman received a tetanus vaccination today. She had her diphtheria/pertussis/tetanus injection following the birth of her first child. She asks whether she should have any other immunisations. Which one of the following is the immunisation recommendation for Aboriginal and Torres Strait Islanders?
A. Immunisation with pneumococcal and annual influenza vaccine for all Aboriginal and Torrens Strait Islanders who are 15 years of age and older
B. Immunisation with pneumococcal and annual influenza vaccine for all Aboriginal and Torrens Strait Islanders who are 50 years of age and older
C. Immunisation with pneumococcal and annual influenza vaccine for all Aboriginal and Torrens Strait Islanders who are 65 years of age and older
D. Immunisation with pneumococcal vaccine for all Aboriginal and Torrens Strait Islanders who are 50 years of age and older and influenza vaccine for those who are 65 years of age and older
E. Immunisation with annual influenza vaccine for all Aboriginal and Torrens Strait Islanders who are 50 years of age and older and pneumococcal vaccine for those who are 65 years of age and older
17. A 21-year-old man presents with recurrent bacterial infections. Investigations show low immunoglobulin (IgG, IgA and IgM) levels and comparison with previous results shows decreasing levels with age. His full blood count is normal. Which one of the following is the most likely diagnosis?
A. Myeloperoxidase deficiency
B. Common variable immunodeficiency
C. Chronic granulomatous disease
D. Hyper-IgM syndrome
E. C1 inhibitor deficiency
18. An 80-year-old man presents with a urinary tract infection. After receiving a dose of intravenous cephazolin, his systolic blood pressure falls from 170 mmHg to 90 mmHg. This patient has a known allergy to penicillin. Hypotension caused by anaphylaxis is suspected. Serum tryptase level is checked. Which one of the following is correct in the interpretation of tryptase results?
A. Peak tryptase levels occur at 4 h after an anaphylactic event
B. Tryptase is more useful in food-related anaphylaxis than medication-related anaphylaxis
C. Single measurement of tryptase has high sensitivity
D. May be significantly elevated in septicaemia
E. High tryptase may be due to mastocytosis
19. A 43-year-old woman presents with persistent itchy hives for 8 weeks. When asked, she says that each individual hive lasts for 2 or 3 days. Physical examination reveals multiple urticarial papules that do not blanch. Three days after initial consultation, she returns and some of the lesions are still present. What would be the next step in her work-up?
A. Thyroid function tests
B. An abdominal computed tomography to exclude an intra-abdominal malignancy
C. Check hepatitis serology
D. Check stool for ova and parasites
E. Perform a biopsy of one of the lesions
20. A 25-year-old man presents with symptoms of nasal congestion, itchy eyes and a tickling sensation in his throat. He has been experiencing these symptoms for several years. Symptoms are present throughout the year and outdoor activities do not worsen the symptoms. He has a cat, which does not sleep in the same room as him. Allergy skin testing indicates a positive response to dust mites and cat dander. Which one of the following therapeutic interventions is the most effective for this patient’s symptoms?
A. Leucotriene receptor antagonists
B. Removal of the allergen from the patient’s environment
C. Anti-histamines
D. Intranasal corticosteroids
E. Cromolyn sodium
21. A 28-year-old man who works in the timber industry has recently had an anaphylactic reaction to a yellow jacket (a type of wasp) sting. He has since been tested and found to be positive on venom skin test. What would be the most appropriate management plan for this man?
A. Venom immunotherapy
B. Commence leucotriene receptor antagonists
C. Avoid outdoor activities
D. Repeat skin test in 6 months
E. Apply wasp repellent on the skin when at work
22. An Aboriginal patient with a history of rheumatic fever develops a sore throat from which Group A streptococci are cultured. The patient is started on treatment with penicillin and the sore throat resolves within a few days. However, on day 7 after initiation of penicillin therapy, the patient develops a fever of 38° C, a generalised maculopapular rash, arthralgia and malaise. The most likely explanation for this is:
A. Development of subacute endocarditis
B. Recurrence of rheumatic fever
C. An IgG- and IgM-mediated response to penicillin
D. A delayed lymphocyte-mediated hypersensitivity reaction to penicillin
E. A delayed IgE-mediated response to penicillin
Theme: Primary immunodeficiency disease (for Questions 23–25)
A. X-linked hypogammaglobulinaemia
B. Selective IgA deficiency
C. Selective IgG deficiency
D. Hereditary angio-oedema
E. Chronic granulomatous disease
F. Common variable immunodeficiency
G. C3 deficiency
H. Ataxia–telangiectasia
23. Which disease is caused by a defect in the ability of neutrophils to kill microorganisms?
24. Which disease is caused by a deficiency in an inhibitor of the C1 component of complement?
25. Which disease is characterised by an inability to synthesise immunoglobulin G (IgG) and other immunoglobulins, resulting in presentations of recurrent pyogenic bacterial infections?
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