Nokea
Which antibody isotype is most abundant in circulation?
- A. IgA
- B. IgG
- C. IgE
- D. IgM
Correct Answer: B
Rationale: The correct answer is B: IgG. IgG is the most abundant antibody isotype in circulation, constituting about 75% of total antibodies. This is because IgG is produced during secondary immune responses and has a longer half-life compared to other isotypes, allowing it to accumulate in circulation. IgA is mainly found in mucosal surfaces, IgE is associated with allergic reactions, and IgM is the first antibody produced in a primary immune response. Therefore, IgG is the most abundant in circulation due to its longevity and role in secondary immune responses.
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Identify the incorrect statement in regard to immunoglobulins (Ig)
- A. Are made up of two identical light chains and two identical heavy chains
- B. Cannot recognize conformational antigens on viral particles
- C. Can recognize only exposed epitopes of pathogens
- D. Expressed early during B cell development on the membrane of B cell precursors (pre- B cells)
Correct Answer: B
Rationale: The correct answer is B because immunoglobulins can indeed recognize conformational antigens on viral particles. Immunoglobulins have variable regions that can bind to a wide range of antigen shapes. Choice A is correct as Ig structure consists of two light and two heavy chains. Choice C is incorrect as immunoglobulins can also bind to internal epitopes. Choice D is incorrect as Ig expression starts during the late B cell development stage.
A patient with systemic lupus erythematosus (SLE) is admitted to the hospital for evaluation and management of acute joint inflammation. Which information obtained in the admission laboratory testing concerns you most?
- A. The blood urea nitrogen (BUN) level is elevated.
- B. The C-reactive protein (CRP) level is increased.
- C. The anti-nuclear antibody (ANA) test is positive.
- D. The lupus erythematosus (LE) cell prep is positive.
Correct Answer: A
Rationale: An elevated BUN level may indicate kidney involvement which is a serious complication of SLE. The other findings are expected in SLE and do not indicate an urgent problem. CRP is a marker of inflammation and positive ANA and LE cell prep are diagnostic of SLE but do not indicate acute complications.
A client with AIDS is terminally ill and wants to name a person as a beneficiary to his life insurance in exchange for immediate cash. What is the term that best describes this arrangement?
- A. Power of attorney
- B. Beneficiary settlement
- C. Viatical settlement
- D. Life insurance guardianship
Correct Answer: C
Rationale: A viatical settlement allows a terminally ill client to sell their life insurance policy for immediate cash naming a beneficiary.
Which of the following immunoglobulins is present normally in plasma at the highest concentration?
- A. IgG
- B. IgM
- C. IgA
- D. IgD
Correct Answer: A
Rationale: The correct answer is A: IgG. IgG is the most abundant immunoglobulin in plasma, comprising around 75% of total immunoglobulins. It is produced in response to infections and provides long-term immunity. IgM is the first antibody produced in response to an infection, but its concentration decreases over time. IgA is mainly found in mucosal areas and secretions. IgD is present in small amounts and its function is not fully understood. Thus, IgG is the correct answer due to its high concentration in plasma and important role in long-term immunity.
Match the immunoglobulins with their primary functions:
- A. 1-C, 2-A, 3-B, 4-D
- B. 1-B, 2-C, 3-D, 4-A
- C. 1-D, 2-B, 3-C, 4-A
- D. 1-A, 2-D, 3-B, 4-C
Correct Answer: A
Rationale: The correct answer is A: 1-C, 2-A, 3-B, 4-D. Immunoglobulins are antibodies with different functions:
1. IgG (C) - Main antibody in secondary immune response.
2. IgA (A) - Found in mucosal areas, neutralizes pathogens.
3. IgM (B) - First antibody produced in primary immune response.
4. IgE (D) - Involved in allergic reactions and defense against parasites. Other choices are incorrect as they mismatch the immunoglobulins with their functions.