Immunology Practice Questions Final

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A positive tuberculin skin tests reaction indicate that

A cell-mediated immune response has occurred

A 3-year-old boy with an X-linked defect in the Bruton tyrosine kinase (BTK) gene is impaired in which of the following mechanisms? A. Antibody-mediated bacterial clearance B. Formation of the membrane attack complex C. Delayed (-type) hypersensitivity (DTH) responses D. IFN-γ secretion by CD4+ T cells E. T-cell precursor migration to the thymus

A. Antibody-mediated bacterial clearance

A child stung by a bee experiences respiratory distress within minutes and lapses into unconsciousness. This reaction is probably mediated by A. IgE antibody. B. IgG antibody. C. sensitized T cells. D. complement. E. IgM antibody.

A. IgE antibody.

Each of the following statements concerning immunologic tolerance is correct EXCEPT: A. Tolerance is not antigen-specific; i.e., paralysis of the immune cells results in a failure to produce a response against many antigens. B. Tolerance is more easily induced in T cells than in B cells. C. Tolerance is more easily induced in neonates than in adults. D. Tolerance is more easily induced by simple molecules than by complex ones.

A. Tolerance is not antigen-specific; i.e., paralysis of the immune cells results in a failure to produce a response against many antigens

An 8-year-old female with a known allergy to peanuts inadvertently ingests a cereal containing traces of peanuts. Within 1 hour, she develops diffuse erythema (redness of the skin) and urticaria associated with respiratory symptoms of shortness of breath and diffuse wheezing. These findings suggest which of the following events? A. Type I hypersensitivity reaction B. Arthus reaction C. FcR-bearing cells binding to host cells coated with IgG D. IgG binding to extracellular matrix of the respiratory passages E. IgM-mediated interaction with cell membranes of lymphocytes

A. Type I hypersensitivity reaction

14.2. A 25-year-old female with a history of penicillin allergy unknown to her physician was given a single injection of penicillin for the treatment of syphilis. Within minutes, she developed diffuse urticaria (hives), tachycardia (rapid heart rate), and hypotension (decrease in blood pressure). This patient has experienced A. anaphylaxis. B. anergy. C. antibody-mediated cytotoxicity. D. asthma. E. contact sensitivity.

A. anaphylaxis

395. Bone marrow transplantation in immunocompromised patients presents which major problem? A. potentially lethal graft-versus-host disease B. high risk of T cell leukemia C. inability to use a live donor D. delayed hypersensitivity

A. potentially lethal graft-versus-host disease

Graft rejection consists of: A. sensitization, when T cells are stimulated, and effector, when they attack the graft. B. sensitization, when B cells are stimulated, and effector, when they attack the graft. C. recognition, when T cells are stimulated, and effector, when they attack the graft. D. recognition, when B cells are stimulated, and effector, when they attack the graft. E. None of the above.

A. sensitization, when T cells are stimulated, and effector, when they attack the graft.

A child disturbs a wasp nest, is stung repeatedly, and goes into shock within minutes, manifesting respiratory failure and vascular collapse. This is MOST likely to be due to A. systemic anaphylaxis. B. serum sickness. C. an Arthus reaction. D. cytotoxic hypersensitivity.

A. systemic anaphylaxis

Insulin-dependent diabetes: A. usually shows juvenile onset. B. is more common in men that in women. C. interferes with fat metabolism. D. seems to be triggered by antibodies. E. None of the above.

A. usually shows juvenile onset.

Which of the following reactions features mast cell degranulation as one of its key features? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: A Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

Which of the following types of hypersensitivity reactions is associated with IgE? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: A Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

Which of the following is NOT packaged within basophil and mast cell granules? A. Prostaglandins B. Histamine C. Heparin D. Tryptase E. All of the above are found in granules.

Answer: A Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 2 Hint: One of these choices is not pre-formed; it is only produced following mast cell/basophil activation.

The effects of histamine in allergic reactions are primarily attributable to its binding which of the following histamine receptors? A. H1 B. H2 C. H3 D. H4 E. None of the above

Answer: A Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 2 Hint: Which receptors activate the allergic response, as opposed to which inhibit degranulation of mast cells?

Which of the following is NOT a means by which type II hypersensitivity reactions occur? A. IgE binding to FcεRI on mast cells B. IgM binding to cell-surface antigens, leading to complement fixation on the cell surface C. Cytotoxic cells with Fc receptors for antibodies bound to the surface of a cell, leading to cytotoxic killing D. Antibody-antigen complexes that form opsonins, leading to phagocyte-driven cell killing E. All of the above are associated with type II hypersensitivity reactions.

Answer: A Section: Antibody-Mediated (Type II) Hypersensitivity Reactions Difficulty: 2 Hint: One of the choices is not associated with type II reactions.

Which of the following BEST describes the difference(s) between types II and III hypersensitivity reactions? A. Direct recognition of cell-surface antigens by antibodies in type II reactions versus deposition of improperly cleared antibody-antigen complexes in type III reactions B. Direct recognition of cell-surface antigens by antibodies in type III reactions versus deposition of improperly cleared antibody-antigen complexes in type II reactions C. Cross-linking of FcεRI by IgE-opsonized pathogens D. Cross-linking of FcγRIIB by IgG-opsonized pathogens E. None of the above

Answer: A Section: Antibody-Mediated (Type II) Hypersensitivity Reactions & Immune Complex-Mediated (Type III) Hypersensitivity Difficulty: 3 Hint: One of the choices involves a different hypersensitivity reaction.

12. Insulin-dependent diabetes: A. usually shows juvenile onset. B. is more common in men that in women. C. interferes with fat metabolism. D. seems to be triggered by antibodies. E. None of the above.

Answer: A Section: Autoimmunity Difficulty: 1 Hint: It is also known as juvenile-onset diabetes.

Which of the following cytokines is NOT generally found in increased concentrations in individuals with chronic inflammation? A. IL-10 B. TNF-α C. IL-1 D. IL-6 E. All of the above are generally elevated in chronic inflammation.

Answer: A Section: Chronic Inflammation Difficulty: 1 Hint: Which of the choices is not pro-inflammatory?

Which of the following is NOT involved in the development of Type II diabetes? A. Antibodies against pancreatic islet cells B. Signaling from IL-6R C. Inactivation of components involved in signaling from the insulin receptor by JNK D. Both B and C are not involved in the development of Type II diabetes. E. None of the above are involved in the development of Type II diabetes.

Answer: A Section: Chronic Inflammation Difficulty: 3 Hint: How does Type II diabetes differ from Type I diabetes?

Which of the following cell types is NOT typically associated with type IV hypersensitivity reactions? A. B cells B. TH1 C. TH17 D. Langerhans cells E. None of the above are typically associated with type IV hypersensitivity reactions.

Answer: A Section: Delayed-Type (Type IV) Hypersensitivity (DTH) Difficulty: 2 Hint: Which of the above types of cells, by means of what they secrete in all of the other types of hypersensitivity reactions, play a lesser role in type IV reactions?

Which of the following are anaphylatoxins? A. C1 and MASP 1 B. C3a and C5a C. C3b and C5b D. C4b and factor D E. C5b and the MAC

Answer: A Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Anaphylatoxins are a cleaved product from important effector molecules found common to each of the three complement pathways.

27. Graft rejection consists of: A. sensitization, when T cells are stimulated, and effector, when they attack the graft. B. sensitization, when B cells are stimulated, and effector, when they attack the graft. C. recognition, when T cells are stimulated, and effector, when they attack the graft. D. recognition, when B cells are stimulated, and effector, when they attack the graft. E. None of the above.

Answer: A Section: Transplantation Immunology Difficulty: 1 Hint: Sensitization of T cells is essential.

Which of the following is an example of a passive immunization? A. Antibodies against rabies given to someone who was bitten by a potentially rabid dog B. Heat-killed flu antigen grown in chicken eggs C. Live viral antigen given on a sugar cube to protect against polio D. Both A and B. E. Both B and C.

Answer: A Section: Vaccines Difficulty: 1 Hint: Passive immunity uses antibodies while active immunity uses antigen.

Vaccines are MOST readily made against: A. bacteria because their cell walls remain relatively unchanged from generation to generation. B. fungi because several species of fungi are commensals therefore priming the immune response to readily produce antibodies to the new vaccine. C. helminths because they are large organisms and make for easy targets. D. prions because they are new microbe so there is much research effort to stop prion related diseases. E. viruses, particularly RNA viruses, because their cell receptors are unchanging and bind human cell receptors.

Answer: A Section: Vaccines Difficulty: 2 Hint: For a vaccine to be efficient, the vaccine's target must be something that does not readily change.

Hypersensitivity reactions to cell surface antigens via IgG or IgM are classified as which type? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: B Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

Which of the following types of hypersensitivity reactions includes the transfusion reaction? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: B Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

Which of the following cell types are implicated in type I hypersensitivity reactions? A. Neutrophils B. Mast cells/basophils C. T cells D. Monocytes E. None of the above

Answer: B Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 1 Hint: Type I reactions have been linked to related cells that can be circulating or tissue-resident.

Which of the following effects is NOT a result of histamine binding to histamine receptor H1? A. Intestinal smooth muscle contraction B. Suppression of mast-cell degranulation C. Increased vascular permeability D. Increased mucous secretion E. All of the above result from histamine binding H1.

Answer: B Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 2 Hint: Which of these blocks stimulation of the allergic response?

15. Multiple sclerosis: A. does not seem to have an environmental component. B. seems to have some genetic component. C. is more common in Europe than North America. D. seems to be primarily mediated by antibodies. E. All of the above.

Answer: B Section: Autoimmunity Difficulty: 1 Hint: If one sibling has it, others are more likely to have it as well.

Chronic stimulation of the tissue regeneration function of the inflammatory response primarily involves which of the following cells? A. T cells B. Fibroblasts C. B cells D. Basophils E. None of the above

Answer: B Section: Chronic Inflammation Difficulty: 2 Hint: Which of the cells is responsible for producing components that will contribute to tissue repair?

Parasitic infections include: A. protozoans. B. protozoans and helminthes. C. prions and viruses. D. prions, viruses, and bacteria. E. protozoans, helminthes, prions, viruses, and bacteria.

Answer: B Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Parasitic infections involve larger microbes.

Each of the following is a step in bacterial infection EXCEPT: A. attachment to host cells. B. the host feels tired or uncomfortable. C. invasion of host tissue. D. proliferation of bacterial cells. E. toxin-induced damage to host cells.

Answer: B Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Pathogens infect, reproduce, and move to the next host.

Primary virulence in fungi indicates: A. an aggressive fungal infection. B. infection by a rare fungal species with high pathogenicity. C. infection by an opportunistic fungal species with low pathogenicity. D. infection by a multi-drug-resistant fungal species. E. infection by multiple fungal species as at once.

Answer: B Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Virulence is divided into primary and opportunistic.

Some species of fungi are part of the normal microbiota or normal microbial flora of a host organism. How does the immune system differentiate between "good" fungi and "bad" fungi? A. Good fungi only reside in certain places and thereby will not trigger an immune response. B. Good fungi are weakly virulent, while bad fungi are highly virulent. C. Fungi are differentiated based on their cytokine production. D. Low levels of any fungi are ignored by the immune system. E. PAMPs such as motifs in peptidoglycan are used to mark fungal cells.

Answer: B Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Normal microbiota are weakly immunogenic and serve to stimulate the immune system so that an immune response can develop quickly (within days).

Sleeping sickness and Chagas's disease are caused by members of the genus Trypanosoma, protozoans that reside in the bloodstream. What is the principle way trypanosomes evade the immune response? A. Antagonistic cytokines are produce by the trypanosome. B. Periodic changes in the surface antigen (VSG) of trypanosomes ensures that at least some cells will survive antibody mediate attacks. C. Trypanosomes are human pathogens and thus immune to human immune responses. D. Trypanosomes invade the brain and red blood cells so that immune effector cells such as macrophages and dendritic cells cannot phagocytize trypanosomes. E. Vaccines are readily available to people in trypanosome infested areas.

Answer: B Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Trypanosomes are masters at hiding from the immune system.

25. Minor histocompatibility locus genes can cause tissue rejection: A. only if major histocompatibility genes also cause rejection. B. even if major histocompatibility genes match properly. C. more quickly than MHC-mediated rejection. D. at the same rate as MHC rejection. E. None of the above

Answer: B Section: Transplantation Immunology Difficulty: 2 Hint: Major is major and minor is minor.

What would happen if a person who is undergoing chemotherapy were given a live virus vaccine against polio? A. The cancer patient would likely develop a strong immune response to the vaccine because a live viral antigen was used. B. The cancer patient would likely develop polio because the immune system is compromised and would not be able to fight off the live virus. C. The chemotherapy the cancer patient is receiving would inactivate the vaccine by killing the live polio virus. D. There would be no effect, as the cancer patient does not produce a high number of immune cells for the polio virus to interact with. E. Using a live viral antigen in a vaccine is lethal to immunocompromised people because their immune system would be overwhelmed and toxic shock would occur.

Answer: B Section: Vaccines Difficulty: 2 Hint: Cancer patients are immunocompromised because of their cancer treatments, long-term illness, and self-immune response.

Which maternal antigens are protective against diseases such as diphtheria, tetanus, streptococcal infections, and measles? A. IgA and IgE B. IgA and IgG C. IgD and IgE D. IgG and IgM E. All classes of immunoglobulins

Answer: B Section: Vaccines Difficulty: 2 Hint: Certain classes of immunoglobulins are capable of crossing the placenta and may be secreted in breast milk.

Formation of immune complexes between antibodies and soluble antigens is considered to be which type of hypersensitivity reaction? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: C Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

Which of the following cell-surface receptors is MOST closely linked to activating type I hypersensitivity reactions? A. FcεRII B. FcγRIIB C. FcεRI D. LFA-1 E. None of the above

Answer: C Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 1 Hint: Which of the above receptors are prevalent on the cells that drive type I hypersensitivity reactions?

The transfusion reaction involves which of the following antigens that are antigenically identical to antigens on the surface of commensal bacteria? A. Fc receptors on the surface of mast cells B. Complement receptors on the surface of APCs C. Carbohydrates on the surface of erythrocytes D. Fc receptors on the surface of cytotoxic cells E. None of the above

Answer: C Section: Antibody-Mediated (Type II) Hypersensitivity Reactions Difficulty: 1 Hint: Not all cell-surface antigens that can be recognized by the immune system are proteins.

16. Rheumatoid arthritis: A. seems to be T-cell mediated, with cytotoxic T cells being primarily responsible. B. is more common in men than in women. C. targets the joint capsules. D. is characterized by juvenile onset. E. All of the above.

Answer: C Section: Autoimmunity Difficulty: 1 Hint: The etiology includes activation of the complement cascade at the joints.

Which of the following is not considered to be a newly emerging infectious disease? A. Ebola B. Legionnaires disease (Legionella) C. Multi-drug-resistant tuberculosis D. SARS E. West Nile

Answer: C Section: Emerging and Re-emerging Infectious Diseases Difficulty: 1 Hint: Most emerging infectious diseases are animal viruses that have managed to jump the species barrier and infect humans.

8. Central tolerance employs all but which of the following mechanisms? A. Apoptosis B. Receptor editing C. Positive selection D. Negative selection E. Clonal deletion

Answer: C Section: Establishment and Maintenance of Tolerance Difficulty: 1 Hint: Removal of autoreactive cells is a major mechanism.

3. The tolerogenic response: A. is not antigen specific. B. leads to apoptosis but not anergy. C. results in cells becoming non-responsive. D. depends of the presentation context. E. affects T cells only.

Answer: C Section: Establishment and Maintenance of Tolerance Difficulty: 2 Hint: Anergy and apoptosis are both mechanisms of tolerance.

Schistomiasis is a debilitating and potentially fatal disease caused by the helminthic parasite Schistosoma. Which antibody is specific for helminth response? A. IgA B. IgD C. IgE D. IgG E. IgM

Answer: C Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Typical immune response to helmiths releases histamine, which recruits eosinophils.

One mechanism that viruses use to avoid the immune response is to bind up immune effector molecules. All of the following methods are used by antibodies to block viral infection EXCEPT: A. antibodies bind to and coat virus particles, preventing viral ligands from binding to cell receptors. B. antibodies trigger complement, which can lyse viral particles or recruit opsonins. C. antibodies stimulate activation of cytotoxic T cells. D. antibodies aid in phagocytosis. E. antibodies compete for binding with viral ligands.

Answer: C Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Viruses must bind to a ligand before they can enter a host cell and begin their life cycle.

24. While MHC matching is important for transplantation, ABO blood group matching is also critical because: A. ABO antigens are expressed on nervous tissue. B. ABO antigens are expressed on muscle cells. C. complement will cause rapid lysis of ABO mismatched cells. D. Both A and C. E. None of the above.

Answer: C Section: Transplantation Immunology Difficulty: 2 Hint: ABO is expressed on connective tissues.

22. Because T cells are essential in graft rejection, nude mice, which lack a thymus: A. will reject grafts the same as wild-type mice. B. will reject grafts more vigorously than wild-type mice. C. will not reject grafts since they lack T cells. D. will not reject grafts since they lack B cells. E. will not reject grafts because of peripheral tolerance.

Answer: C Section: Transplantation Immunology Difficulty: 2 Hint: Without a thymus, T-cell development does not occur.

Several vaccines are combination vaccines and are used to vaccinate people against two or more pathogens. One example of a combination vaccine is the TDaP vaccine (tetanus, diphtheria, pertussis). How does a combination vaccine develop immunologic memory to more than one pathogen? A. Allergic reactions are less common with combination vaccines than with single-antigen vaccines. B. Combination vaccines develop immunity against very similar or the same (broad spectrum) antigens. C. Combination vaccines are more economical to produce than single vaccines. D. Each antigen target included in the combination vaccine must be different enough so that the immune system can recognize the target antigen on the pathogen cell. E. Similar antigens can be chemically modified so that immune system will recognize each antigen as unique.

Answer: C Section: Vaccines Difficulty: 1 Hint: For a vaccine to develop long-term safe immunity, the vaccine's target antigen must be specific.

Why does active immunity produce long-term immunity better than passive immunity? A. Active immunity always leads to having the illness though in a milder form than an unvaccinated individual. B. Antibodies do not produce long term immunity because they breakdown after two weeks. C. During active immunity, antigens for the disease are presented to the immune system through classical antigen presentation mechanisms, so an active B-cell response and immunologic memory develop. D. Long-term storage of antibodies maintains vaccine integrity however antigens cannot be stored long term. E. Both A and B.

Answer: C Section: Vaccines Difficulty: 2 Hint: Developing immunologic memory is the single most important factor in vaccine design. Vaccines that do not develop memory cells are not good vaccines and will require frequent boosters.

The tuberculin reaction is an example of which type of hypersensitivity? A. Type I B. Type II C. Type III D. Type IV E. None of the above

Answer: D Section: All Sections Difficulty: 1 Hint: What is the tuberculin reaction detecting, and how are its effects detected?

The Arthus reaction is considered to be which of the following hypersensitivity types? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: D Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

A normal individual should only produce IgE in response to which of the following types of antigens? A. Antigens from extracellular bacterial antigens B. Antigens from intracellular bacterial antigens C. Viral antigens D. Parasite antigens E. All of the above

Answer: D Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 1 Hint: IgE is normally only produced against one of the types of antigens listed above.

Which of the following cytokines is NOT generally associated with allergic reactions? A. TNF-α B. GM-CSF C. IL-4 D. TGF-β E. All of the above are associated with allergic reactions.

Answer: D Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 2 Hint: Which of the listed cytokines have an immunosuppressive effect?

11. Hashimoto's thyroiditis targets the thyroid and: A. is more common in men than in women. B. shows juvenile onset. C. is primarily T-cell mediated. D. leads to hypothyroidism. E. All of the above.

Answer: D Section: Autoimmunity Difficulty: 2 Hint: It reduces thyroid function.

18. Many autoimmune disorders are treated with immunosuppressive drugs, which produce other problems. Antigen specific immunotherapy would be much better because: A. they would target only the autoreactive cells. B. they would not induce general suppression of the immune system. C. they would produce a general reduction in inflammation. D. Both A and B. E. All of the above.

Answer: D Section: Autoimmunity Difficulty: 3 Hint: The key to effective immune function is the ability to mount specific responses.

6. Apoptosis is: A. similar to necrosis. B. important in peripheral tolerance, but not central tolerance. C. important in central tolerance, but not peripheral tolerance. D. impaired in Fas-deficient systems. E. None of the above.

Answer: D Section: Establishment and Maintenance of Tolerance Difficulty: 2 Hint: Apoptosis is widely used.

4. Tolerance is promoted by all of the following circumstances EXCEPT: A. high doses of antigen. B. persistent antigen. C. oral introduction of antigen. D. presence of adjuvant. E. low levels of costimulation.

Answer: D Section: Establishment and Maintenance of Tolerance Difficulty: 2 Hint: Oral polio vaccine is unusual in its effectiveness.

2. Which of the following statements does NOT describe tolerogens accurately? A. They can be the same molecules as immunogens. B. They lead cells to become unresponsive. C. They are part of peripheral tolerance. D. They only affect B cells. E. All of the above.

Answer: D Section: Establishment and Maintenance of Tolerance Difficulty: 2 Hint: Tolerogens are equivalent to immunogens, but in different context.

Acquired fungal immunity is supported by: A. multiple antifungals and vaccines that are available. B. normal flora species that produce new antimicrobial compounds. C. plasma-cell and memory B-cell activation. D. TH1 and INF-ɣ production. E. TNF-α and TC production.

Answer: D Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Cytokine production is required for long-term immunity to fungal pathogens.

______ is known as an endotoxin. A. C3a B. Capsular proteins C. Flagellar proteins (H antigen) D. Lipid A of the LPS in gram-negative cells E. Peptidoglycan in gram-positive cells

Answer: D Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Endotoxins are not secreted.

How do Plasmodium cells avoid immune clearance? A. Antagonistic cytokines are produced by the Plasmodium cells. B. Periodic changes in the surface antigen (VSG) of Plasmodium ensures that at least some cells will survive antibody mediate attacks. C. Plasmodium cells show multi-drug resistance. D. Plasmodium invades red blood cells so that immune-effector cells such as macrophages and dendritic cells cannot phagocytize Plasmodium cells. E. TNF-α is produced in large amounts by Plasmodium, thus overwhelming the immune response and creating a cytokine storm.

Answer: D Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Plasmodium is the causative agent of malaria. People with sickling red blood cells are less likely to have malaria.

Which of the following is recognized by the innate immune system and triggers an immune response that will produce antiviral cytokines and trigger effector molecules? A. Complement B. IgA C. IL-2 D. PAMPs E. TNF-α

Answer: D Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: The innate immune system looks for common, non-specific identifiers on viruses.

Cryptococcus may spread throughout an infected host. By what mechanism is Cryptococcus controlled by the acquired immune system? A. Activation of TH cells B. Degranulation of eosinophils and IgE C. Expression of TNF-α D. Granuloma formation E. Plasma cell activation

Answer: D Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Granulomas represent an attempt by the immune system to wall off a pathogen.

Viruses, like many good pathogens, have adapted to survive in their hosts. Which of the following scenarios would be MOST favorable to viral transmission and long term survival of the viral species? A. Virus X enters a host cell, produces many progeny viruses (virions), and lyses the host cell. B. Virus X enters the host cell and merges viral DNA with the host DNA so that the virus is copied into all progeny host cells. C. Virus X enters the host cells, merges viral DNA with the host DNA until the host cell is stressed, and then begins to produce many virions eventually lysing the host cell. D. Virus X enters the host cell and consistently makes virions at a low level so that all host cell functions are not disrupted. E. Virus X enters the host cell, makes many progeny virions, and releases virions through exocytosis so that each virion is wrapped in the host cell plasma membrane. The host cell will eventually die or be targeted by the immune system for apoptosis.

Answer: D Section: Importance of Barriers to Infection and the Innate Response Difficulty: 3 Hint: Good pathogens produce progeny without killing their host cells.

19. Autografts will be rejected only rarely because of all but which of the following? A. They are from the same individual. B. They are MHC matched. C. They do not trigger an immune response. D. They have Th17 cells. E. All of the above.

Answer: D Section: Transplantation Immunology Difficulty: 1 Hint: "Auto" means self.

Hypersensitivity reactions to penicillin have been identified that correspond to which of the above types of reactions? A. Type I hypersensitivity B. Type II hypersensitivity C. Type III hypersensitivity D. Type IV hypersensitivity E. All of the above

Answer: E Section: All Sections Difficulty: 2 Hint: Know how each type of hypersensitivity reaction occurs.

Which of the following cell types are targets of the products of mast-cell degranulation, as well as the mediators produced by mast cells following degranulation? A. Smooth muscle B. Nervous tissue C. Hematopoietic cells D. Epithelial cells E. All of the above

Answer: E Section: Allergy: A Type I Hypersensitivity Reaction Difficulty: 2 Hint: Do the mediators released by mast cells only influence one type of cell?

13. Myasthenia gravis is an autoimmune disease that: A. is triggered by antibodies. B. targets the neuromuscular junction. C. leads to destruction of muscle cells. D. Both A and B. E. All of the above.

Answer: E Section: Autoimmunity Difficulty: 1 Hint: Acetylcholine receptors are on muscle cells.

10. Autoimmune diseases: A. involve a failure of central tolerance. B. involve a failure of peripheral tolerance. C. lead to tissue destruction. D. Both A and B. E. All of the above.

Answer: E Section: Autoimmunity Difficulty: 1 Hint: Multiple failures must take place for autoimmunity to develop.

14. Systemic lupus erythematosus: A. is more common in women than in men. B. is antibody mediated. C. targets multiple organs. D. Both B and C. E. All of the above.

Answer: E Section: Autoimmunity Difficulty: 1 Hint: Systemic means spread throughout.

17. Individuals who express HLA-B27 are 90 times more likely to develop the autoimmune disorder ankylosing spondylitis than individuals with a different HLA allele at this locus. This leads to the conclusion that: A. HLA-B27 causes ankylosing spondylitis. B. individuals with HLA-B27 will develop ankylosing spondylitis. C. autoimmune disorders must have genetic components. D. patients with ankylosing spondylitis express HLA-B27. E. None of the above is true.

Answer: E Section: Autoimmunity Difficulty: 2 Hint: Likelihood does not equal causation.

Which of the following is a potential cause of chronic inflammation? A. Obesity B. Infectious agents C. Tissue damage D. Intestinal commensal microbiota components E. All of the above

Answer: E Section: Chronic Inflammation Difficulty: 2 Hint: Is there only one single cause of chronic inflammation?

Re-emerging infectious diseases prevent a major problem worldwide. What actions can be taken to prevent the spread of re-emerging infectious diseases such as whooping cough (Bordetella pertussis)? A. Create new antibiotics, antifungals, and antivirals to treat existing stains of pathogen and limit development of multi-drug resistances. B. Ensure proper precautions during travel, especially for airborne pathogens. C. Maintain rigorous vaccination programs for all healthy individuals. D. Provide herd immunity during outbreaks. E. All of the above are good preventative actions.

Answer: E Section: Emerging and Re-emerging Infectious Diseases Difficulty: 2 Hint: Preventing the spread of infectious disease involves proper treatment for infected individuals and vaccinations where possible for healthy individuals.

1. Central tolerance: A. is the first step of tolerance mechanisms. B. affects both T cells and B cells. C. deletes cells that are autoreactive. D. occurs in the bone marrow and thymus. E. All of the above.

Answer: E Section: Establishment and Maintenance of Tolerance Difficulty: 1 Hint: Autoreactivity can involve both T cells and B cells.

5. Tolerance is promoted by: A. induction of anergy. B. induction of apoptosis. C. regulation of activity of cells. D. Both A and B. E. All of the above.

Answer: E Section: Establishment and Maintenance of Tolerance Difficulty: 1 Hint: Autoreactivity is such a large potential problem that multiple systems to control it are used.

9. Peripheral tolerance: A. Is caused by costimulation without TcR-MHC+ peptide interaction. B. Is caused by TcR-MHC+ peptide interaction without costimulation. C. Leads to anergy. D. Both A and C. E. Both B and C.

Answer: E Section: Establishment and Maintenance of Tolerance Difficulty: 1 Hint: It is antigen specific.

7. Maintaining immunologically protected sites, such as the eye: A. allows sequestration of antigens. B. reduces central tolerance. C. can lead to autoreactivity secondary to injury. D. can reduce background reactivity. E. All of the above.

Answer: E Section: Establishment and Maintenance of Tolerance Difficulty: 2 Hint: Keeping self antigens away from immune cells reduces interactions, both during development and afterwards.

Which of the following is NOT an explanation for inefficient clearing of antibody-antigen complexes that could lead to type III hypersensitivity reactions? A. High affinity for tissues of particular antigens B. Antigens that are prone to formation of lattices when bound by antibodies C. Highly charged antigens D. Compromised phagocytic system E. All of the above could explain inefficient clearing of antibody-antigen complexes.

Answer: E Section: Immune Complex-Mediated (Type III) Hypersensitivity Difficulty: 2 Hint: There is no single explanation for the development of type III hypersensitivity reactions.

Influenza virus is an annual concern in the United States and worldwide. Each year, millions of people receive the flu vaccine to protect against the influenza virus. What two viral ligands does the flu vaccine produce immunity to? A. Hemagglutinin and TNF-α B. Hemagglutinin and N-acetyl glucosamine C. N-acetyl glucosamine and Neuraminidase D. N-acetyl glucosamine and reverse transcriptase E. Neuraminidase and Hemagglutinin

Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Influenza viruses are named after their H and N antigens.

By which mechanisms can bacterial pathogens evade a host immune response? A. Avoiding phagocytosis by the production of a capsule B. Escape of the phagolysosome within phagocytic cells C. Neutralization of digestive enzymes found within phagocytic cells D. Both A and B. E. All of the above.

Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Phagocytes capture pathogens and degrade them using hydrolytic enzymes.

Leishmaniasis is a disease that can either be fatal to its host or will be cleared by the immune response of the host. Which pathway is responsible for clearing leishmaniasis? A. Memory B cells B. Complement C. Plasma cells D. TC cells E. TH cells Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Production of TNF and interferon is the main immune response to Leishmania major.

Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 1 Hint: Production of TNF and interferon is the main immune response to Leishmania major.

Anaphylatoxins stimulate a localized inflammatory response, which includes mast-cell degranulation, vasodilation, and recruitment of lymphocytes and phagocytic cells. What is the purpose of this localized immune response? A. Mast cells contain histamine, which triggers vasodilation, which will increase blood flow to an infected area so that higher numbers of white blood cells will be recruited. B. Serum proteins contain specific and nonspecific immune effector molecules to bind up and neutralize the invading pathogen and any toxins. C. Vasodilation locally increases the temperate of an infected area so that bacterial proteins become denatured. D. Vasodilation increases tenderness at the site of infection and causes edema (swelling) to that the host is careful not to overuse or tax the infected area. E. All of the above.

Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Anaphylatoxins trigger an immune cascade to recruit other immune-effector molecules.

People encounter fungi on a daily basis, yet few healthy individuals develop fungal infections. Each of the following are mechanisms of the innate immune system that help prevent or limit fungal infections in healthy individuals EXCEPT: A. neutrophils are especially good a phagocytizing fungal cells. B. normal microbial flora (commensals) limit fungal growth by toxin (antimicrobial) production. C. normal microbial flora use available nutrients and colonization space on the host, which makes the host an inhospitable environment for fungal cells. D. PAMPs such as b-glucans, mannans, and chitin are recognized by innate immune cells. E. several species of fungi are able to block PRR binding.

Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Normal flora species are the primary defense against fungal infections. Other non-specific immune cells can also recognize non-host motifs in fungal cell walls.

Viruses such as Epstein-Barr virus, cytomegalovirus, and HIV are capable of suppressing the immune system by: A. binding antibodies but avoiding an immune response. B. infecting lymphocytes or phagocytic cells. C. production of cytokine antagonists. D. wrapping progeny viral particles in the host-cell plasma membrane. E. Both B and C.

Answer: E Section: Importance of Barriers to Infection and the Innate Response Difficulty: 2 Hint: Viruses can evade or decrease an immune response by targeting host immune cells or cytokines.

20. Isografts are NOT usually rejected because: A. they are between genetically identical individuals. B. they are MHC matched. C. they do not trigger an immune response. D. they are syngeneic. E. All of the above.

Answer: E Section: Transplantation Immunology Difficulty: 1 Hint: "Syngeneic" means shared genes.

26. Allografts can be accepted without use of immunosuppressive drugs if: A. they lack alloantigens, such as cartilage. B. cells are grafted to a site that is immunologically privileged. C. tolerance has been induced previously, such as non-identical twins. D. Both A and B. E. All of the above.

Answer: E Section: Transplantation Immunology Difficulty: 1 Hint: Lack of antigens leads to a lack of immune response.

21. Rejection of allografts: A. does not depend on MHC mismatching. B. demonstrates immunological specificity. C. demonstrates immunological memory. D. Both A and B. E. Both B and C.

Answer: E Section: Transplantation Immunology Difficulty: 1 Hint: Rejection does depend on mismatches of MHC.

23. Kidney transplant infiltrates show both CD4+ and CD8+ T cells. This suggests that to reduce graft rejection: A. CD4+ T cells should be depleted. B. CD8+ T cells should be depleted. C. Both CD4+ and CD8+ cells should be depleted. D. Inflammatory cells should be depleted. E. None of the above are viable treatments.

Answer: E Section: Transplantation Immunology Difficulty: 3 Hint: What effect will T-cell depletion have on immune function?

Modern-day vaccines try to elicit an immune response from: A. memory B cells. B. cytotoxic T cells. C. hematopoietic stem cells. D. innate immune cells. E. naïve B cells and TH cells.

Answer: E Section: Vaccines Difficulty: 1 Hint: Good vaccines should activate both B and T cells.

What is herd immunity? A. A global vaccination day established by the World Health Organization to ensure every person on the planet is vaccinated against a particular pathogen. The last herd immunity day was in the early 1980s with smallpox. B. A vaccination program started by progressive nations to prevent the spread of prion diseases such as Mad Cow (BSE). C. Herd immunity refers to a special vaccination method whereby immunocompromised individuals are given vaccines made only of antibodies. D. Receiving all government recommended vaccines in one day. This produces the strongest immune response possible but frequently leaves the person being vaccine experience malaise (generally feeling bad) and feverish. E. Vaccinating the majority of a population to protect immunocompromised individuals from a particular pathogen.

Answer: E Section: Vaccines Difficulty: 2 Hint: Herd immunity is utilized when there is insufficient vaccine available to vaccinate everyone and to protect the immunocompromised.

Vaccination type: Rotavirus

Attenuated

A 3-month-old male infant has recurrent infections and is found to have an impaired ability to kill microbes by the nitroblue tetrazolium test (which evaluates effectiveness of degradative enzymes). Which of the following conditions is most likely responsible for the findings in this patient? A. Chediak-Higashi syndrome B. Chronic granulomatous disease C. Hereditary angioedema D. HIV/AIDS E. Waldenström macroglobulinemia

B. Chronic granulomatous disease

A female neonate has a malformed jaw, cardiac abnormalities, and hypocalcemia, in addition to diminished cell-mediated and B-cell responses. Which of the following immune deficiencies should be included in the differential diagnosis of this patient? A. Adenosine deaminase (ADA) deficiency B. DiGeorge syndrome C. Hereditary angioedema D. Severe combine immunodeficiency disease (SCID) E. Wiskott-Aldrich syndrome

B. DiGeorge syndrome

Which one of the following sequences is appropriate for testing a patient for antibody against the AIDS virus with the ELISA procedure? (The assay is carried out in a plastic plate with an incubation and a wash step after each addition except the final one.) A. patient's serum/enzyme substrate/HIV antigen/enzyme-labeled antibody against HIV B. HIV antigen/patient's serum/enzyme-labeled antibody against human gamma globulin/enzyme substrate C. enzyme-labeled antibody against human gamma globulin/patient's serum/HIV antigen/enzyme substrate D. enzyme-labeled antibody against HIV/HIV antigen/patient's serum/enzyme substrate

B. HIV antigen/patient's serum/enzyme-labeled antibody against human gamma globulin/enzyme substrate

The main advantage of passive immunization over active immunization is that A. it can be administered orally. B. it provides antibody more rapidly. C. antibody persists for a longer period. D. it contains primarily IgM.

B. It provides antibody more rapidly

If you measure the ability of cytotoxic T cells from an HLA-B27 person to kill virus X-infected target cells, which one of the following statements is CORRECT? A. Any virus X-infected target cell will be killed. B. Only virus X-infected cells of HLA-B27 type will be killed. C. Any HLA-B27 cell will be killed. D. No HLA-B27 cell will be killed.

B. Only virus X-infected cells of HLA-B27 type will be killed

What is the role of class II MHC proteins on donor cells in graft rejection? A. They are the receptors for interleukin-2, which is produced by macrophages when they attack the donor cells. B. They are recognized by helper T cells, which then activate cytotoxic T cells to kill the donor cells. C. They induce the production of blocking antibodies that protect the graft. D. They induce IgE which mediates graft rejection.

B. They are recognized by helper T cells, which then activate cytotoxic T cells to kill the donor cells.

A 35-year-old male presents with headache, fatigue, light-headedness, dyspnea (difficulty in breathing), and tachycardia (rapid heart rate). Laboratory findings reveal decreased hemoglobin and a positive direct Coombs test (presence of antibodies on erythrocyte surfaces). The patient is currently taking an antibiotic for symptoms of upper respiratory infection. These findings suggest which type of hypersensitivity? A. Type I, mediated by IgG antibodies B. Type II, mediated by IgG antibodies C. Type III, mediated by IgG antibodies D. Type III, mediated by IgG or IgM antibodies E. Type IV, mediated by CD4+ T cells

B. Type II, mediated by IgG antibodies

A positive tuberculin skin test (a delayed hypersensitivity reaction) indicates that A. a humoral immune response has occurred. B. a cell-mediated immune response has occurred. C. both the T and B cell systems are functional. D. only the B cell system is functional.

B. a cell-mediated immune response has occurred.

Individuals of blood group type AB A. are Rh(d)-negative. B. are "universal recipients" of transfusions. C. have circulating anti-A and anti-B antibodies. D. have the same haplotype.

B. are "universal recipients" of transfusions

Chemically-induced tumors have tumor-associated transplantation antigens that A. are always the same for a given carcinogen. B. are different for two tumors of different histologic type even if induced by the same carcinogen. C. are very strong antigens. D. do not induce an immune response.

B. are different for two tumors of different histologic type even if induced by the same carcinogen.

A 6-month-old male infant has diarrhea, extensive fungal infections, and skin rashes and has failed to gain weight. He is de먀cient in both T- and B-cell function. The thymus is of normal size. The most likely prospect for permanent restoration of normal immunity for this patient would be A. an antibiotic "cocktail" given at regular intervals. B. bone marrow transplantation. C. exogenous immunoglobulins administered periodically. D. isolation to an antiseptic environment. E. thymic hormones given throughout his life.

B. bone marrow transplantation.

A patient with a central nervous system disorder is maintained on the drug methyldopa. Hemolytic anemia develops, which resolves shortly after the drug is withdrawn. This is MOST probably an example of A. atopic hypersensitivity. B. cytotoxic hypersensitivity. C. immune-complex hypersensitivity. D. cell-mediated hypersensitivity.

B. cytotoxic hypersensitivity.

Minor histocompatibility locus genes can cause tissue rejection: A. only if major histocompatibility genes also cause rejection. B. even if major histocompatibility genes match properly. C. more quickly than MHC-mediated rejection. D. at the same rate as MHC rejection. E. None of the above

B. even if major histocompatibility genes match properly.

A 21-year-old woman has a history since childhood of recurrent episodes of swelling of the submucosal and subcutaneous tissue of the gastrointestinal and respiratory tracts. Her C1 inhibitor level is less than 5% of the reference value. These findings support a diagnosis of A. DiGeorge syndrome. B. hereditary angioedema. C. nutrition-based immune deficiency. D. paroxysmal nocturnal hemoglobinuria. E. Wiskott-Aldrich syndrome.

B. hereditary angioedema.

In a mixed-lymphocyte culture, lymphocytes from person X, who is homozygous for the HLA-Dw7 allele, are irradiated and then cultured with lymphocytes from person Z. It is found that DNA synthesis is NOT stimulated. The proper conclusion to be drawn is that A. person Z is homozygous for HLA-Dw7. B. person Z is homozygous or heterozygous for HLA-Dw7. C. person Z is heterozygous for HLA-Dw7. D. person Z does not carry the HLA-Dw7 allele.

B. person Z is homozygous or heterozygous for HLA-Dw7.

Proteins from two samples of animal blood, A and B, were tested by the double-diffusion (Ouchterlony) test in agar against antibody to bovine albumin. Which sample(s) contain horse blood? A. sample A B. sample B C. both samples D. neither sample

B. sample B

Multiple sclerosis: A. does not seem to have an environmental component. B. seems to have some genetic component. C. is more common in Europe than North America. D. seems to be primarily mediated by antibodies. E. All of the above.

B. seems to have some genetic component.

392. A patient with severe asthma gets no relief from antihistamines. The symptoms are MOST likely to be caused by A. interleukin-2. B. slow-reacting substance A (leukotrienes). C. serotonin. D. bradykinin.

B. slow-reacting substance A (leukotrienes).

In the immune response to a hapten-protein conjugate, in order to get anti-hapten antibodies it is essential that A. the hapten be recognized by helper T cells. B. the protein be recognized by helper T cells. C. the protein be recognized by B cells. D. the hapten be recognized by suppressor T cells.

B. the protein be recognized by helper T cells

The principal difference between cytotoxic (type II) and immune complex (type III) hypersensitivity is A. the class (isotype) of antibody. B. the site where antigen-antibody complexes are formed. C. the participation of complement. D. the participation of T cells.

B. the site where antigen-antibody complexes are formed.

An Rh-negative woman married to a heterozygous Rh-positive man has three children. The probability that all three of their children are Rh-positive is A. 1:2. B. 1:4. C. 1:8. D. zero.

C. 1:8.

AIDS is caused by a human retrovirus that kills A. B lymphocytes. B. lymphocyte stem cells. C. CD4-positive T lymphocytes. D. CD8-positive T lymphocytes.

C. CD4-positive T lymphocytes.

A 5-year-old girl has a small deletion in chromosome 22. She has impaired thymus development with a significant deficiency in the number of functional T cells. The most likely etiology for these findings is A. adenosine deaminase (ADA) deficiency. B. Chediak-Higashi syndrome. C. DiGeorge syndrome. D. hereditary angioedema. E. severe combined immunodeficiency (SCID).

C. DiGeorge syndrome.

A 24-year-old male presents with fever, cough, and night sweats. Examination reveals an elevated temperature, increased respiratory rate, oral thrush (fungal infection), and decreased breath sounds in the right midlung field. Laboratory testing reveals a CD4 count of 60/mL (reference range: 400/mL). On the basis of these findings, the most likely underlying process is A. autoimmune disease with pneumonia. B. bacterial pneumonia. C. HIV/AIDS with possible mycobacterium tuberculosis. D. hypersensitivity pneumonitis. E. Mycobacterium tuberculosis infection only

C. HIV/AIDS with possible mycobacterium tuberculosis

Central tolerance employs all but which of the following mechanisms? A. Apoptosis B. Receptor editing C. Positive selection D. Negative selection E. Clonal deletion

C. Positive selection

Polyomavirus (a DNA virus) causes tumors in "nude mice" (nude mice do not have a thymus, because of a genetic defect) but not in normal mice. The BEST interpretation is that A. macrophages are required to reject polyomavirus-induced tumors. B. natural killer cells can reject polyomavirus-induced tumors without help from T lymphocytes. C. T lymphocytes play an important role in the rejection of polyomavirus-induced tumors. D. B lymphocytes play no role in rejection of polyomavirus-induced tumors.

C. T lymphocytes play an important role in the rejection of polyomavirus-induced tumors.

Two dissimilar inbred strains of mice, A and B, are crossed to yield an F1 hybrid strain, AB. If a large dose of spleen cells from an adult A mouse is injected into an adult AB mouse, which one of the following is MOST likely to occur? A. The spleen cells will be destroyed. B. The spleen cells will survive and will have no effect in the recipient. C. The spleen cells will induce a graft-versus-host reaction in the recipient. D. The spleen cells will survive and induce tolerance of strain A grafts in the recipient.

C. The spleen cells will induce a graft-versus-host reaction in the recipient.

A 45-year-old female with a history of hepatitis C viral infection presents with decreased renal function, hypertension (increased blood pressure), and anemia. Laboratory findings reveal decreased serum C3. Her urine sediment contains leukocytes, erythrocytes, and red blood cell casts (a proteinaceous mold of the renal tubules that includes erythrocytes). Her renal biopsy is consistent with glomerulonephritis. These findings suggest which type of hypersensitivity A. Type I, mediated by CD4+ T cells B. Type II, mediated by IgM antibodies C. Type III, mediated by IgG antibodies D. Type IV, mediated by CD4+ T cells E. Type IV, mediated by IgG (and sometimes IgM) antibodies

C. Type III, mediated by IgG antibodies

Reaction to poison ivy or poison oak is A. an IgG-mediated response. B. an IgE-mediated response. C. a cell-mediated response. D. an Arthus reaction.

C. a cell-mediated response.

In which one of the following situations would a graft-versus-host reaction be MOST likely to occur? (Mouse strains A and B are highly inbred; AB is an F1 hybrid between strain A and strain B.) A. newborn strain A spleen cells injected into a strain B adult B. x-irradiated adult strain A spleen cells injected into a strain B adult C. adult strain A spleen cells injected into an x-irradiated strain AB adult D. adult strain AB spleen cells injected into a strain A newborn

C. adult strain A spleen cells injected into an x-irradiated strain AB adult

A delayed hypersensitivity reaction is characterized by A. edema without a cellular infiltrate. B. an infiltrate composed of neutrophils. C. an infiltrate composed of helper T cells and macrophages D. an infiltrate composed of eosinophils.

C. an infiltrate composed of helper T cells and macrophages

397. Grafts between genetically identical individuals (i.e., identical twins) A. are rejected slowly as a result of minor histocompatibility antigens. B. are subject to hyperacute rejection. C. are not rejected, even without immunosuppression. D. are not rejected if a kidney is grafted, but skin grafts are rejected.

C. are not rejected, even without immunosuppression.

While MHC matching is important for transplantation, ABO blood group matching is also critical because: A. ABO antigens are expressed on nervous tissue. B. ABO antigens are expressed on muscle cells. C. complement will cause rapid lysis of ABO mismatched cells. D. Both A and C. E. None of the above.

C. complement will cause rapid lysis of ABO mismatched cells.

A patient skin-tested with purified protein derivative (PPD) to determine previous exposure to Mycobacterium tuberculosis develops induration at the skin test site 48 hours later. Histologically, the reaction site would MOST probably show A. eosinophils. B. neutrophils. C. helper T cells and macrophages. D. B cells.

C. helper T cells and macrophages

393. Hypersensitivity to penicillin and hypersensitivity to poison oak are both A. mediated by IgE antibody. B. mediated by IgG and IgM antibody. C. initiated by haptens. D. initiated by Th-2 cells.

C. initiated by haptens.

394. A recipient of a 2-haplotype MHC-matched kidney from a relative still needs immunosuppression to prevent graft rejection because A. graft-versus-host disease is a problem. B. minor histocompatibility antigens will not be matched. C. minor histocompatibility antigens will not be matched. D. complement components will not be matched.

C. minor histocompatibility antigens will not be matched.

Which one of the following is the BEST method of reducing the effect of graft-versus-host disease in a bone marrow recipient? A. matching the complement components of donor and recipient B. administering alpha interferon C. removing mature T cells from the graft D. removing pre-B cells from the graft

C. removing mature T cells from the graft

The tolerogenic response: A. is not antigen specific. B. leads to apoptosis but not anergy. C. results in cells becoming non-responsive. D. depends of the presentation context. E. affects T cells only

C. results in cells becoming non-responsive.

Rheumatoid arthritis: A. seems to be T-cell mediated, with cytotoxic T cells being primarily responsible. B. is more common in men than in women. C. targets the joint capsules. D. is characterized by juvenile onset. E. All of the above.

C. targets the joint capsules.

Because T cells are essential in graft rejection, nude mice, which lack a thymus: A. will reject grafts the same as wild-type mice. B. will reject grafts more vigorously than wild-type mice. C. will not reject grafts since they lack T cells. D. will not reject grafts since they lack B cells. E. will not reject grafts because of peripheral tolerance.

C. will not reject grafts since they lack T cells.

A certain population of lymphocytes inhibits activity of autoreactive lymphocytes. Such inhibitory cells express which markers?

CD4 CD25

AIDs is caused by a human retrovirus that kills

CD4+ T cells

Many autoimmune disorders are treated with immunosuppressive drugs, which produce other problems. Antigen specific immunotherapy would be much better because: A. they would target only the autoreactive cells. B. they would not induce general suppression of the immune system. C. they would produce a general reduction in inflammation. D. Both A and B. E. All of the above.

D. Both A and B.

This question is based on the same strains of mice described in the previous question. If adult AB spleen cells are injected into a newborn B mouse, which one of the following is MOST likely to occur? A. The spleen cells will be destroyed. B. The spleen cells will survive without any effect on the recipient. C. The spleen cells will induce a graft-versus-host reaction in the recipient. D. The spleen cells will survive and induce tolerance of strain A grafts in the recipient.

D. The spleen cells will survive and induce tolerance of strain A grafts in the recipient.

Autografts will be rejected only rarely because of all but which of the following? A. They are from the same individual. B. They are MHC matched. C. They do not trigger an immune response. D. They have Th17 cells. E. All of the above.

D. They have Th17 cells.

Which of the following statements does NOT describe tolerogens accurately? A. They can be the same molecules as immunogens. B. They lead cells to become unresponsive. C. They are part of peripheral tolerance. D. They only affect B cells. E. All of the above.

D. They only affect B cells.

Which of the following is/are initiated by the interaction of host cell membranes with IgM or IgG antibody but never IgE antibody? A. Arthus reactions B. Serum sickness C. Type I hypersensitivity reactions D. Type II hypersensitivity reactions E. Type IV hypersensitivity reactions

D. Type II hypersensitivity reactions

390. A patient with rheumatic fever develops a sore throat from which beta-hemolytic streptococci are cultured. The patient is started on treatment with penicillin, and the sore throat resolves within several days. However, 7 days after initiation of penicillin therapy the patient develops a fever of 103°F, a generalized rash, and proteinuria. This MOST probably resulted from A. recurrence of the rheumatic fever. B. a different infectious disease. C. an IgE response to penicillin. D. an IgG-IgM response to penicillin. E. a delayed hypersensitivity reaction to penicillin.

D. an IgG-IgM response to penicillin.

Penicillin is a hapten in both humans and mice. To explore the hapten-carrier relationship, a mouse was injected with penicillin covalently bound to bovine serum albumin and, at the same time, with egg albumin to which no penicillin was bound. Of the following, which one will induce a secondary response to penicillin when injected into the mouse 1 month later? A. penicillin B. penicillin bound to egg albumin C. egg albumin D. bovine serum albumin

D. bovine serum albumin

Graft and tumor rejection are mediated primarily by A. non-complement-fixing antibodies. B. phagocytic cells. C. helper T cells. D. cytotoxic T cells.

D. cytotoxic T cells.

A 2-month-old male infant presents with persistent diarrhea, signs and symptoms of Pneumocystis carinii pneumonia, and an oral fungal infection with Candida albicans. His weight is in the 10th percentile. Test results for HIV are negative by polymerase chain reaction. The most likely cause of these findings is A. grossly reduced levels of B cells. B. an X-linked inheritance of HLA genes. C. defective isotype switching. D. defective T-cell function. E. selective IgA deficiency.

D. defective T-cell function.

Which category of hypersensitivity BEST describes hemolytic disease of the newborn caused by Rh incompatibility? A. atopic or anaphylactic B. cytotoxic C. immune complex D. delayed

D. delayed

Apoptosis is: A. similar to necrosis. B. important in peripheral tolerance, but not central tolerance. C. important in central tolerance, but not peripheral tolerance. D. impaired in Fas-deficient systems. E. None of the above.

D. impaired in Fas-deficient systems.

The BEST method to demonstrate IgG on the glomerular basement membrane in a kidney tissue section is the A. precipitin test. B. complement fixation test. C. agglutination test. D. indirect fluorescent-antibody test.

D. indirect fluorescent-antibody test.

The minor histocompatibility antigens on cells A. are detected by reaction with antibodies and complement. B. are controlled by several genes in the major histocompatibility complex. C. are unimportant in human transplantation. D. induce reactions that can cumulatively lead to a strong rejection response.

D. induce reactions that can cumulatively lead to a strong rejection response.

Hashimoto's thyroiditis targets the thyroid and: A. is more common in men than in women. B. shows juvenile onset. C. is primarily T-cell mediated. D. leads to hypothyroidism. E. All of the above.

D. leads to hypothyroidism.

Tolerance is promoted by all of the following circumstances EXCEPT: A. high doses of antigen. B. persistent antigen. C. oral introduction of antigen. D. presence of adjuvant. E. low levels of costimulation.

D. presence of adjuvant.

Involves macrophages and helper T cells

Delayed hypersensitivity

Allografts can be accepted without use of immunosuppressive drugs if: A. they lack alloantigens, such as cartilage. B. cells are grafted to a site that is immunologically privileged. C. tolerance has been induced previously, such as non-identical twins. D. Both A and B. E. All of the above.

E. All of the above.

Autoimmune diseases: A. involve a failure of central tolerance. B. involve a failure of peripheral tolerance. C. lead to tissue destruction. D. Both A and B. E. All of the above.

E. All of the above.

Central tolerance: A. is the first step of tolerance mechanisms. B. affects both T cells and B cells. C. deletes cells that are autoreactive. D. occurs in the bone marrow and thymus. E. All of the above.

E. All of the above.

Isografts are NOT usually rejected because: A. they are between genetically identical individuals. B. they are MHC matched. C. they do not trigger an immune response. D. they are syngeneic. E. All of the above.

E. All of the above.

Maintaining immunologically protected sites, such as the eye: A. allows sequestration of antigens. B. reduces central tolerance. C. can lead to autoreactivity secondary to injury. D. can reduce background reactivity. E. All of the above.

E. All of the above.

Myasthenia gravis is an autoimmune disease that: A. is triggered by antibodies. B. targets the neuromuscular junction. C. leads to destruction of muscle cells. D. Both A and B. E. All of the above.

E. All of the above.

Systemic lupus erythematosus: A. is more common in women than in men. B. is antibody mediated. C. targets multiple organs. D. Both B and C. E. All of the above.

E. All of the above.

Tolerance is promoted by: A. induction of anergy. B. induction of apoptosis. C. regulation of activity of cells. D. Both A and B. E. All of the above.

E. All of the above.

Peripheral tolerance: A. Is caused by costimulation without TcR-MHC+ peptide interaction. B. Is caused by TcR-MHC+ peptide interaction without costimulation. C. Leads to anergy. D. Both A and C. E. Both B and C.

E. Both B and C.

Rejection of allografts: A. does not depend on MHC mismatching. B. demonstrates immunological specificity. C. demonstrates immunological memory. D. Both A and B. E. Both B and C.

E. Both B and C.

Kidney transplant infiltrates show both CD4+ and CD8+ T cells. This suggests that to reduce graft rejection: A. CD4+ T cells should be depleted. B. CD8+ T cells should be depleted. C. Both CD4+ and CD8+ cells should be depleted. D. Inflammatory cells should be depleted. E. None of the above are viable treatments.

E. None of the above are viable treatments.

Individuals who express HLA-B27 are 90 times more likely to develop the autoimmune disorder ankylosing spondylitis than individuals with a different HLA allele at this locus. This leads to the conclusion that: A. HLA-B27 causes ankylosing spondylitis. B. individuals with HLA-B27 will develop ankylosing spondylitis. C. autoimmune disorders must have genetic components. D. patients with ankylosing spondylitis express HLA-B27. E. None of the above is true.

E. None of the above is true.

The 8-year-old patient recovered from the event described in Study Question 14.4. The next day, she went to play with a friend who had recently returned from a family trip to Asia. The friend gave her a Japanese lacquered box as a gift. Two days later, she developed itchiness in her hands, and her mother noticed that they were bright red. Her mother also noticed clear fluid vesicles on her right forearm. These findings suggest which type of hypersensitivity? A. Type I, mediated by CD4+ T cells B. Type I, mediated by CD8+ T cells C. Type II, mediated by CD8+ T cells D. Type III, mediated by CD4+ T cells E. Type IV, mediated by CD4+ T cells

E. Type IV, mediated by CD4+ T cells

The following mechanisms may be involved in the clinical efficacy of desensitization therapy to treat patients with allergies to known allergens.

Enhance production of IgG, which binds allergen before it reaches mast cells, decreased sensitivity of mast cells and basophils to degranulation by allergen, decreased production of IgE antibody

Which statement regarding GVH disease is incorrect?

GVH requires natural killer cells

Auto-antibodies to receptor for thyroid stimulating hormones

Graves disease

Th1 cell reaction to thyroid antigens

Hashimoto's thyroiditis

Which molecules is/are released during anaphylaxis?

Histamine, PGD2, LTC4, Leukotriene

Rheumatoid factor, found in synovial fluid of patients with rheumatoid arthritis, is most frequently found to be

IgM reacting with H-chain determinants of IgG

Involves mast cells and basophils

Immediate (atopic) hypersensitivity

Irregular deposition of IgG along glomerular basement membrane

Immune complex hypersensitivity

A patient with severe asthma gets no relief from antihistamine. The symptoms are most likely to be caused by

Leukotrienes

Auto-antibodies to acetylcholine receptor

Myasthenia gravis

A 30 yr old female presents with fatigue, weight loss, arthritis of her hands and a malar (butterfly) rash. Blood test reveal decrease hemoglobin and the presence of antinuclear antibodies. These findings support which diagnoses paired with its underlying process?

Systemic lupus erythematosus: autoantibodies to chromosomal proteins

A 29 yr old woman visited her doctor after experiencing joint pain and stiffness in the mornings for several months. A blood test for antiphospholipid antibody was ordered and came back positive. Results from other blood tests revealed elevated titers for serum IgG and antibodies for ribonucleoproteins. A urine test was positive for protein. What is most likely diagnosis?

Systemic lupus erythmatosus

The usual sequence of events in allergic reaction is as follows

The allergen binds to IgE fixed to mast cells

The role that herd immunity plays in vaccination is to

To stop person to person transmission

A previous healthy 45 yr old male present with rhinorrhea, nasal congestion and persistent respiratory symptom several months after returning to his home in New Orleans after Hurricane Katrina. He has noticed mold growing along the wall of his home. Skin testing for sensitivity to common mold spores gave positive results to several of them in less than 30 minutes. These findings indicate an example of

Type I hypersensitivity

Despite having recovered fully from influenza the previous winter, a 56 yr old man becomes ill after being exposed to a colleague with influenza virus. Which mechanisms permits his reinfection despite previous exposure to influenza virus?

Viral variant evade the immune response against the original virus

A delayed hypersensitivity reaction is characterized by

an infiltrate composed of helper T cells and macrophages

Primary immunodeficiencies

are inherited

Grafts between genetically identical individuals

are not rejected, even without immunosuppression

RD was involved in a car accident and had burns on his right forearm. Doctors removed skin from his leg and grafted it onto his arm. What type of transplant is this?

autograft

The failure to inactivate or eliminate self-reactive cells results in

autoimmunity

The principal difference between cytotoxic (II) and immune complex (III) hypersensitivity is a.The class of antibody b.Whether the antibody reacts with the antigen on the cell or reacts with antigen before it interacts with the cell c.The participation of complement d.The participation of T cells

b.Whether the antibody reacts with the antigen on the cell or reacts with antigen before it interacts with the cell

Glucocorticoids exert immunosupprssive effects by

binding to intracellular receptors and influencing gene transcription

While MHC matching in important for transplantation, ABO blood group matching is also critical because

complement will cause rapid lysis of ABO mismatched cells

Vaccination type: Polio-Salk

inactivated/killed

Hyper IgM syndrome

is a result of a helper T cell defect

A line of tumor cells prepared from one mouse is injected into an MHC-matched recipient. The tumor was destroyed within 5 days. When tissues from the recipient were analyzed, the animal had a negligible cytotoxic T lymphocyte (CTL) response against the tumor. Flow cytometry revealed that the tumor cells expressed very low level of MHC class I molecules. The best explanation for the destruction of the tumor cells in the recipient is that

natural killer cells recognized the absence of MHC class I molecules and killed the tumor cells

Which is best method of reducing the effect of graft versus host disease is a hone marrow recipient?

removing mature T cells from the graft

Vaccination type: Haemophilus influenza

subunit

Vaccination type: streptococcus pneumoniae

subunit

A preliminary clinical trial showed that a humanized anti-CD28 monoclonal antibody prolonged the graft survival in patients who had had a kidney allograft. The probable mechanism responsible for this effect is best explained by

the binding of anti-CD28 to T cells which interferes with signal transduction needed for T cell activation

In order to prevent Rhesus hemolytic disease of newborn developing in babies that are at risk because of the parents blood group types, to whom and at what time should Rhogam (anti-Rhesus) be administered?

the mother should receive it within 3 days of birth

Th1 cell response to pancreatic beta cells

type 1 diabetes mellitus


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