What is a characteristic feature of atopy?

Correct Answer: A

Rationale: Step-by-step rationale: 1. Atopy is a genetic predisposition to produce IgE antibodies in response to allergens. 2. IgE antibodies play a crucial role in allergic reactions. 3. Individuals with atopy have an exaggerated immune response to allergens. 4. Excess production of IgA antibodies (B) and suppressed immune response to allergens (C) are not characteristic features of atopy. 5. Delayed hypersensitivity reactions (D) involve a different immune mechanism compared to the immediate IgE-mediated response in atopy.

Correct Answer: B

Rationale: The correct answer is B: Pulmonary hemorrhage and glomerulonephritis. Goodpasture's syndrome is an autoimmune disease characterized by the presence of anti-glomerular basement membrane antibodies, leading to damage in the kidneys (glomerulonephritis) and lungs (pulmonary hemorrhage). Granuloma formation (A), contact dermatitis (C), and bronchoconstriction and vasodilation (D) are not characteristic features of Goodpasture's syndrome. Granulomas are more commonly seen in conditions like sarcoidosis, contact dermatitis is an inflammatory skin condition, and bronchoconstriction and vasodilation are features of allergic reactions or asthma, not typically seen in Goodpasture's syndrome.

Correct Answer: C

Rationale: Granulomatous hypersensitivity is characterized by the formation of granulomas in response to persistent antigen exposure. Systemic lupus erythematosus (SLE) is an autoimmune disease involving immune complex deposition and inflammation, not granuloma formation. Crohn's disease, sarcoidosis, and tuberculosis are commonly associated with granulomatous hypersensitivity due to their chronic inflammatory nature and granuloma formation in affected tissues. SLE does not typically present with granulomas, making it the correct answer.

Correct Answer: C

Rationale: Step 1: Lyme disease is rarely fatal if treated promptly. Step 2: Choice C states that Lyme disease is usually fatal if not treated successfully, which is incorrect. Step 3: Therefore, this statement indicates a need for review as it spreads misinformation. Step 4: Choices A, B, and D are accurate and align with the information provided in the educational program. Step 5: In summary, the need to review the material is highlighted by the inaccurate statement in choice C, as the other choices provide correct information on Lyme disease.

Correct Answer: C

Rationale: The correct answer is C: Expressed on naïve T cells. L-Selectin is a cell adhesion molecule expressed on the surface of naïve T cells. It plays a crucial role in the initial attachment of T cells to high endothelial venules (HEV) in lymphoid tissues, facilitating T cell entry into lymph nodes. It specifically binds to ligands on HEV, allowing T cells to extravasate into lymphoid tissues. Choice A is incorrect because L-Selectin is primarily expressed on naïve T cells rather than effector T cells. Choice B is incorrect as L-Selectin is expressed on HEV, not by them. Choice D is incorrect because L-Selectin is involved in the initial attachment of T cells to endothelial cells, rather than being required for extravasation into tissues.