Inflammation and Repair Practice Questions

Q: Chediak Higashi syndrome is characterized by the following EXCEPT:

Neutrophilia. **Explanation:** **Chediak-Higashi Syndrome (CHS)** is a rare autosomal recessive disorder caused by a mutation in the **LYST gene** (Lysosomal Trafficking Regulator) [1]. This mutation leads to defective vesicle fusion and protein trafficking [1]. **Why "Neutrophilia" is the correct answer (the exception):** Patients with CHS actually present with **Neutropenia**, not neutrophilia [1]. The defect in lysosomal trafficking interferes with normal hematopoiesis in the bone marrow, leading to ineffective granulopoiesis and the premature destruction of white blood cells. **Analysis of other options:** * **Giant Granules (Option D):** This is the morphological hallmark of CHS. Due to disordered fusion of endosomes and lysosomes, massive, non-functional "giant" granules are seen in neutrophils, eosinophils, and melanocytes [1]. * **Defective Degranulation (Option B):** The giant granules are unable to fuse properly with phagosomes [1]. This prevents the release of hydrolytic enzymes into the phagocytic vacuole. * **Delayed Microbial Killing (Option C):** Because degranulation is impaired, the delivery of bactericidal enzymes to the ingested microbe is delayed or absent, leading to recurrent pyogenic infections [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Tetrad:** 1. Oculocutaneous albinism (melanocyte defect), 2. Recurrent pyogenic infections (staphylococci/streptococci), 3. Progressive neurological defects, 4. Bleeding tendencies (platelet dense body defect) [1]. * **Diagnosis:** Peripheral blood smear showing **giant peroxidase-positive granules** in neutrophils [1]. * **Accelerated Phase:** Most patients eventually enter a "hemophagocytic lymphohistiocytosis" (HLH) phase characterized by hepatosplenomegaly and pancytopenia. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 245-246.

Q: Which of the following cytokines is secreted by classically activated macrophages (M1)?

IL-1. **Explanation:** Macrophages can be activated via two distinct pathways: the **Classical (M1)** pathway and the **Alternative (M2)** pathway [1]. **1. Why IL-1 is correct:** Classically activated macrophages (M1) are induced by microbial products (like LPS) and IFN-γ [1]. Once activated, M1 macrophages function as "pro-inflammatory" cells. They secrete potent inflammatory cytokines, primarily **IL-1, IL-12, IL-23, and TNF** [1]. These cytokines serve to recruit more leukocytes and initiate the acute inflammatory response. M1 cells also produce reactive oxygen species (ROS) and nitric oxide (NO) to facilitate microbicidal activity [1]. **2. Why the other options are incorrect:** * **IL-2:** This is a T-cell growth factor primarily secreted by **Th1 cells**, not macrophages. It stimulates the proliferation of T-lymphocytes and NK cells. * **IL-4:** This is the hallmark cytokine of the **Th2 response**. It actually inhibits M1 activation and instead promotes **Alternative (M2) macrophage activation**, which is involved in tissue repair and anti-inflammatory responses [1]. * **IL-3:** This is a hematopoietic growth factor secreted by activated T-cells that stimulates the production of cells in the bone marrow. **High-Yield Clinical Pearls for NEET-PG:** * **M1 (Classical):** Induced by IFN-γ; Pro-inflammatory; Secretes **IL-1, IL-12, TNF**; Involved in inflammation and tissue destruction [1]. * **M2 (Alternative):** Induced by **IL-4, IL-13**; Anti-inflammatory; Secretes **IL-10, TGF-β**; Involved in tissue repair, fibrosis, and wound healing [1]. * **Memory Aid:** **M1** = "Murder" (Microbicidal/Inflammation); **M2** = "Mend" (Repair/Healing). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 104-107.

Question 1

Which of the following statements regarding the SIRS diagnostic criteria is incorrect?

Accepted Answer

Bandemia <5%

Answer

Bandemia >10%

Answer

Leukocytosis >12,000 cells/mm³

Answer

Respiratory rate >20 breaths/min

Question 2

Which of the following helps in generating the oxygen burst in neutrophils?

Accepted Answer

NADPH oxidase

Answer

Superoxide dismutase

Answer

Catalase

Answer

Glutathione peroxidase

Question 3

"CACHECTIN" is produced by?

Accepted Answer

macrophage

Answer

neutrophils

Answer

basophils

Answer

eosinophils

Question 4

Serum amyloid A protein levels are increased in which of the following conditions?

Accepted Answer

Ankylosing spondylitis

Answer

Alzheimer’s disease

Answer

Chronic renal failure

Answer

Malignant hypertension

Question 5

Chediak Higashi syndrome is characterized by the following EXCEPT:

Accepted Answer

Neutrophilia

Answer

Defective degranulation

Answer

Delayed microbial killing

Answer

Giant granules

Question 6

All of the following are false regarding vascular leakage in acute inflammation, except:

Accepted Answer

A hallmark of acute inflammation is increased permeability in the post-capillary venules.

Answer

Chemical mediators such as histamine play a role in delayed vascular leakage.

Answer

Transcytosis is not a contributing factor to vascular leakage.

Answer

In most cases, vascular leakage starts several hours after injury.

Question 7

Serotonin, a mediator of inflammation, is secreted/released by which of the following cells?

Accepted Answer

Platelets

Answer

Leukocytes

Answer

Endothelial cells

Answer

Mast cells

Question 8

In a granuloma, epithelioid cells and giant cells are derived from which cell type?

Accepted Answer

Monocyte-macrophages

Answer

T lymphocytes

Answer

B lymphocytes

Answer

Mast cells

Question 9

Which of the following cytokines is secreted by classically activated macrophages (M1)?

Accepted Answer

IL-1

Answer

IL-2

Answer

IL-4

Answer

IL-3

Question 10

Which of the following is an exogenous pyrogen?

Accepted Answer

Lipopolysaccharide

Answer

TNF-a

Answer

Neurotropic factor

Answer

IL-6

Inflammation and Repair — MCQs

Inflammation and Repair — MCQs

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