WBR0491
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Immunology |
| Sub Category | SubCategory::Pulmonology |
| Prompt | [[Prompt::A 7-year-old boy was brought to the emergency department for severe cough since three hours. The mother reports that her son woke up from sleep and started coughing non-stop to an extent that she noticed his color became blue. The mother mentions that this is not the first time it happens with him as he has been having severe bouts of cough at night or following his exercise classes at school. A diagnosis of asthma is suspected. Which of the following mediators is involved in the class switching of immunoglobulin to IgE which is involved in the pathophysiology of the patient's condition?]] |
| Answer A | AnswerA::Interleukin 1 |
| Answer A Explanation | [[AnswerAExp::Interleukin 1 affects the activity of hypothalamus, the thermoregulatory center, which leads to a raise of a body temperature, so called fever. That is why IL-1 is called endogenous pyrogen. Interleukin 1 is not involved in asthma.]] |
| Answer B | AnswerB::Interleukin 2 |
| Answer B Explanation | [[AnswerBExp::Interleukin 2 is necessary for the growth, proliferation, and differentiation of T cells to become 'effector' T cells. It is secreted by the T helper cells. Interleukin 2 is not involved in asthma.]] |
| Answer C | AnswerC::Interleukin 3 |
| Answer C Explanation | [[AnswerCExp::Interleukin 3 is secreted by basophils and activated T cells to support growth and differentiation of T cells from the bone marrow in an immune response. Interleukin 3 is not involved in asthma.]] |
| Answer D | AnswerD::Interleukin 4 |
| Answer D Explanation | [[AnswerDExp::Interleukin 4 induces B-cell class switching to IgE, and up-regulates MHC class II production. IL-4 decreases the production of Th1 cells, macrophages, IFN-gamma, and dendritic cell IL-12.]] |
| Answer E | AnswerE::Interleukin 5 |
| Answer E Explanation | [[AnswerEExp::Interleukin 5 is a major regulator of eosinophil accumulation in tissues, and can modulate eosinophil behavior at every stage from maturation to survival. Interleukin 5 is not involved in asthma.]] |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::The patient is suffering from symptoms of cough at night and following exercise, which are consistent with a diagnosis of asthma. Both interleukins 4 and 5 are involved in asthma. Interleukin 4 pronotes class switching of immunoglobulin into IgE and Interleukin 5 plays a role in the activation and the proliferation of eosinophils.
Educational objective: Shown below is an image summarizing the roles of interleukins and the cells that secrete them.
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| Approved | Approved::No |
| Keyword | WBRKeyword::Interleukin, WBRKeyword::asthma, WBRKeyword::immunoglobulin |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
