Nokea
Which of the following statements is true?
- A. MHC class I and MHC class II molecules both consist of two transmembrane protein chains
- B. MHC class I molecules have one peptide-binding site whereas MHC class II molecules have two peptide-binding sites
- C. A given MHC molecule binds only one peptide at a time
- D. MHC molecules on the cell surface have empty peptide-binding sites in the absence of infection
Correct Answer: C
Rationale: The correct answer is C because a given MHC molecule can bind only one peptide at a time. This is essential for the proper presentation of antigens to immune cells. MHC class I and class II molecules do not consist of two transmembrane protein chains (A), MHC class I molecules have one peptide-binding site while MHC class II molecules have one peptide-binding site (B), and MHC molecules on the cell surface typically have peptides bound to their peptide-binding sites, even in the absence of infection (D).
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What accurately describes passive acquired immunity (select all that apply)?
- A. Pooled gamma globulin
- B. Immunization with antigen
- C. Temporary for several months
- D. Immediate, lasting several weeks
Correct Answer: C
Rationale: Passive acquired immunity involves the transfer of antibodies from one individual to another, such as pooled gamma globulin, maternal immunoglobulins, and immediate protection that lasts for weeks to months.
Find the unmatched pair with respect to immune function:
- A. Interferons: protection from viral infections
- B. ROS: killing of engulfed pathogens
- C. Mast cells: acute phase response
- D. Selectins: role in leukocyte extravasation
Correct Answer: C
Rationale: The correct answer is C: Mast cells: acute phase response. Mast cells are actually involved in allergic responses, not the acute phase response of the immune system. The acute phase response is primarily mediated by cytokines and acute-phase proteins. Interferons protect against viral infections, ROS help kill pathogens inside cells, and selectins aid in leukocyte extravasation during inflammation.
A client is being administered the first dose of belimumab for a systemic lupus erythematosus flare. What actions by the nurse are most appropriate? (Select one that does not apply.)
- A. Observe the client for at least 2 hours afterward.
- B. Instruct the client about the monthly infusion schedule.
- C. Inform the client not to drive or sign legal papers for 24 hours.
- D. Ensure emergency equipment is working and nearby.
Correct Answer: C
Rationale: The correct answer is C: Inform the client not to drive or sign legal papers for 24 hours. This is because belimumab can cause dizziness and fatigue as side effects, which may impair the client's ability to drive or make important decisions. It is crucial for the nurse to ensure the safety of the client and others by advising against these activities for 24 hours post-administration.
Choice A: Observing the client for at least 2 hours is important for monitoring immediate adverse reactions, but it is not the most appropriate action in this scenario.
Choice B: Instructing the client about the monthly infusion schedule is important for treatment adherence, but it is not the most immediate concern after the first dose administration.
Choice D: Ensuring emergency equipment is working and nearby is important for safety precautions, but advising the client not to drive or sign legal papers is more directly related to the potential side effects of belimumab.
Some top-selling drugs that are currently prescribed to treat certain immune-mediated diseases are actually monoclonal antibodies specific for:
- A. An inflammatory cytokine
- B. An inflammatory cytokine receptor
- C. Lymphocytes of the T cell lineage
- D. Two of these responses are correct
Correct Answer: D
Rationale: The correct answer is D because some top-selling drugs for immune-mediated diseases target either an inflammatory cytokine or its receptor. Monoclonal antibodies specific for an inflammatory cytokine can block its activity, while those targeting the receptor can prevent the cytokine from binding and triggering immune responses. Choices A and B are correct examples of drugs targeting inflammatory pathways. Choice C, targeting T cell lymphocytes, is less common for immune-mediated diseases compared to targeting cytokines or receptors. Therefore, D is the correct answer as it encompasses both common targeting strategies.
Which cells play a key role in linking innate and adaptive immunity?
- A. B cells
- B. Dendritic cells
- C. Eosinophils
- D. NK cells
Correct Answer: B
Rationale: The correct answer is B: Dendritic cells. Dendritic cells are antigen-presenting cells that bridge the innate and adaptive immune responses by capturing and presenting antigens to T cells, thus initiating the adaptive immune response. They are crucial for activating T cells and initiating specific immune responses.
A: B cells are responsible for antibody production in the adaptive immune response, not for linking innate and adaptive immunity.
C: Eosinophils are primarily involved in parasitic infections and allergic reactions, not in linking innate and adaptive immunity.
D: NK cells are part of the innate immune system and are involved in detecting and killing infected cells, but they do not directly link innate and adaptive immunity.