What is a serious side effect of antimalarial DMARDs?

Correct Answer: A

Rationale: The correct answer is A: Retinal damage. Antimalarial DMARDs like hydroxychloroquine can cause retinal damage, leading to vision loss. This is a serious side effect because it can be irreversible and impact quality of life. Bone marrow suppression (B), pulmonary fibrosis (C), and hepatotoxicity (D) are potential side effects of other medications but are not commonly associated with antimalarial DMARDs. It is important to monitor patients on antimalarials for early signs of retinal damage to prevent permanent vision loss.

Correct Answer: A

Rationale: The correct answer is A: Belimumab. Belimumab is a monoclonal antibody that specifically targets B-cell activating factor (BAFF) and is approved for the treatment of SLE. BAFF plays a role in B-cell survival and maturation, which are key factors in the pathogenesis of SLE. Methotrexate (B), Hydroxychloroquine (C), and Leflunomide (D) are also used in the treatment of SLE, but they do not specifically target the underlying mechanisms of the disease like Belimumab does. Methotrexate is more commonly used for arthritis in SLE, Hydroxychloroquine is used for mild SLE cases, and Leflunomide is used for rheumatoid arthritis.

Correct Answer: B

Rationale: The correct answer is B because Type II hypersensitivity reactions are mediated by immunoglobulins G or M, not just IgM alone. Step-by-step rationale: 1. Type I hypersensitivity: Correctly matched with examples like hay fever and anaphylaxis. 2. Type II hypersensitivity: Incorrectly matched with IgM, as it is mediated by IgG or IgM. 3. Type III hypersensitivity: Correctly matched with immune complex deposits in blood vessel walls. 4. Type IV hypersensitivity: Correctly matched with examples like poison ivy and transplant rejection. In summary, choice B is incorrect because it inaccurately describes the immunoglobulin involved in Type II hypersensitivity reactions.

Correct Answer: B

Rationale: Rationale: The presence of nuclear remnants on red blood cells in sickle cell disease indicates Howell-Jolly bodies, a sign of functional asplenia due to autosplenectomy. This occurs in sickle cell disease due to chronic vaso-occlusive crises leading to infarction and fibrosis of the spleen. Asplenism increases the risk of infections, particularly encapsulated organisms. Summary: A: Hypersplenism is incorrect because it would result in increased removal of red blood cells without nuclear remnants. C: Hepatomegaly is incorrect as it is not typically associated with the presence of nuclear remnants on red blood cells. D: Bone marrow failure is incorrect as it does not specifically lead to the presence of Howell-Jolly bodies on red blood cells in sickle cell disease.

Correct Answer: B

Rationale: The correct answer is B: NK cells don't require any prior exposure before being active. NK cells are part of the innate immune system and can quickly respond to infected or abnormal cells without prior exposure or activation. They recognize stressed cells by detecting changes in surface markers. Choice A is incorrect because NK cells originate from lymphoid precursor cells. Choice C is incorrect because NK cells do not require prior exposure for their activity, although their response can be enhanced by cytokines. Choice D is incorrect because NK cells are not specific for particular viruses; they target a broad range of infected or abnormal cells.