Cytokines and Chemokines Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Cytokines and Chemokines. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Cytokines and Chemokines Indian Medical PG Question 1: The acute inflammatory response is predominantly mediated by which type of immune cells?
- A. T lymphocytes
- B. Neutrophils (Correct Answer)
- C. Both B and T lymphocytes
- D. B lymphocytes
Cytokines and Chemokines Explanation: ***Neutrophils***
- **Neutrophils** are the **primary mediators** of the **acute inflammatory response**, being the first immune cells recruited to sites of injury or infection (usually within minutes to hours) [1], [3].
- They are **innate immune cells** that perform phagocytosis, release antimicrobial substances, and form neutrophil extracellular traps (NETs) to combat pathogens [1].
- Neutrophils constitute **50-70% of circulating leukocytes** and are the hallmark cells found in acute inflammation [3].
*T lymphocytes*
- **T lymphocytes** are central to **cell-mediated immunity** in the adaptive immune response, requiring several days for activation and clonal expansion [2].
- They recognize specific antigens through TCRs and are not involved in the immediate, non-specific phase of acute inflammation.
- T cells play roles in **chronic inflammation** and coordinating adaptive immunity, not acute responses.
*B lymphocytes*
- **B lymphocytes** mediate **humoral immunity** by producing antibodies during the adaptive immune response [1].
- Their activation, differentiation into plasma cells, and antibody production take days to weeks, making them irrelevant to the rapid acute inflammatory response.
- B cells are not recruited to acute inflammatory sites in the initial phase.
*Both B and T lymphocytes*
- While both are critical for **adaptive immunity** and host defense, neither B nor T lymphocytes are primary mediators of acute inflammation [4].
- The acute inflammatory response relies on **innate immune cells** (neutrophils, macrophages, mast cells) for immediate, non-specific protection before adaptive immunity develops [4].
Cytokines and Chemokines Indian Medical PG Question 2: Which of the following is not classified as a chemokine?
- A. IL-8
- B. Eotaxin
- C. MCP-1
- D. IL-1 (Correct Answer)
Cytokines and Chemokines Explanation: ***Histamine***
- Histamine is a **biogenic amine** involved in local immune responses, not classified as a chemokine [1].
- It functions primarily in **vasodilation** and **increased vascular permeability**, contrasting with chemokine roles.
*IL-1*
- IL-1 is a **cytokine** that plays a role in inflammatory responses but is not a chemokine [1].
- It primarily acts as a mediator for **fever** and **acute inflammation**.
*IL-8*
- IL-8 is a **chemokine** specifically known for attracting **neutrophils** to sites of inflammation [1].
- It plays a crucial role in **immune response** and is classified within the CXC chemokine family.
*Eotaxin*
- Eotaxin is a specific **chemokine** that primarily attracts **eosinophils** to sites of inflammation, especially in allergic reactions.
- It is involved in the pathogenesis of **asthma** and other eosinophil-associated conditions.
**References:**
[1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 93-94.
Cytokines and Chemokines Indian Medical PG Question 3: Which of the following is the platinum-based chemotherapeutic agent used as first-line treatment for ovarian carcinoma?
- A. Cyclophosphamide
- B. Methotrexate
- C. Cisplatin (Correct Answer)
- D. Dacarbazine
Cytokines and Chemokines Explanation: ***Cisplatin***
- **Cisplatin** is a platinum-based chemotherapy drug that forms **DNA cross-links**, inhibiting DNA synthesis and leading to the death of rapidly dividing cells, making it highly effective against **ovarian carcinoma**.
- It is a cornerstone of chemotherapy regimens for ovarian cancer, often used in combination with other agents such as paclitaxel.
*Methotrexate*
- **Methotrexate** is an **antimetabolite** that inhibits dihydrofolate reductase, thereby interfering with DNA synthesis.
- While it is used in various cancers like leukemia, lymphoma, and some solid tumors (e.g., breast cancer, gestational trophoblastic disease), it is **not a primary recommended drug for ovarian carcinoma**.
*Cyclophosphamide*
- **Cyclophosphamide** is an **alkylating agent** that causes DNA damage, leading to cell death.
- It is used in many cancers, including lymphoma, breast cancer, and some leukemias, but it is **not a first-line or primary agent for ovarian carcinoma** in contemporary treatment guidelines.
*Dacarbazine*
- **Dacarbazine** is an **alkylating agent** primarily used in the treatment of **malignant melanoma** and Hodgkin lymphoma.
- It is **not indicated for the treatment of ovarian carcinoma**.
Cytokines and Chemokines Indian Medical PG Question 4: Which is NOT a feature of chronic inflammation?
- A. Mononuclear cells
- B. Neutrophil predominance (Correct Answer)
- C. Fibrosis
- D. Granulation tissue
Cytokines and Chemokines Explanation: ***Neutrophil predominance***
- **Neutrophil predominance** is characteristic of **acute inflammation**, where these cells are among the first responders to injury or infection [1].
- In chronic inflammation, neutrophils are typically present in much smaller numbers compared to mononuclear cells, or their presence indicates an acute exacerbation [3].
*Mononuclear cells*
- **Mononuclear cells**, such as **macrophages**, **lymphocytes**, and **plasma cells**, are the hallmark cellular infiltrates of chronic inflammation [1].
- These cells are responsible for sustained immune responses, tissue destruction, and repair processes [2].
*Fibrosis*
- **Fibrosis**, or the deposition of **collagen** by fibroblasts, is a common outcome of chronic inflammation as the body attempts to repair ongoing tissue damage [3].
- It leads to **scarring** and functional impairment of affected organs [4].
*Granulation tissue*
- **Granulation tissue** is an early phase of **tissue repair** during chronic inflammation, characterized by the proliferation of **fibroblasts** and new **blood vessels (angiogenesis)** [5].
- It represents the body's effort to fill tissue defects and prepare for eventual fibrous scar formation [5].
**References:**
[1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 195-196.
[2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 107-109.
[3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 196-197.
[4] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 200-202.
[5] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 194-195.
Cytokines and Chemokines Indian Medical PG Question 5: Which interleukin is specifically secreted by Th17 cells?
- A. IFN Gamma
- B. IL6
- C. IL-17 (Correct Answer)
- D. IL-22
Cytokines and Chemokines Explanation: ***IL22***
- Th17 cells predominantly secrete **IL-17** and also produce **IL-22**, which is significant in mucosal immunity and inflammation [1].
- **IL-22** plays a crucial role in the response to infections and in the pathogenesis of inflammatory diseases.
*IL16*
- IL-16 is primarily associated with **chemoattractant and regulatory functions** for lymphocytes and not directly secreted by Th17 cells.
- It is involved in **eosinophil and T cell activation**, which is not characteristic of the Th17 response.
*IFN Gamma*
- IFN-gamma is mainly produced by **Th1 cells** and is critical for **cell-mediated immunity**, which is distinct from the function of Th17 cells.
- It plays a role in activating **macrophages**, unlike Th17 cells which focus on **neutrophil recruitment** and inflammation.
*IL6*
- While IL-6 is a pro-inflammatory cytokine that can be involved in various immune responses, it is not primarily secreted by Th17 cells.
- It is produced by a variety of cell types including fibroblasts and macrophages, acting as a mediator in the **acute phase response**.
**References:**
[1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 158-160.
Cytokines and Chemokines Indian Medical PG Question 6: TNF and IL-1 are produced by
- A. Neutrophils
- B. Monocytes
- C. Activated Macrophages (Correct Answer)
- D. Lymphocytes
Cytokines and Chemokines Explanation: ***Activated Macrophages***
- Activated macrophages are the primary source of **TNF** and **IL-1**, which are key cytokines in inflammatory responses [1].
- They play a crucial role in **immune modulation** and act as important mediators of the inflammatory process [1].
*Lymphocytes*
- Lymphocytes primarily produce **antibodies** and other cytokines like **IL-2**, but they are not the main producers of TNF and IL-1.
- Their role is more prominent in the adaptive immune response rather than in the innate response where TNF and IL-1 are more directly involved.
*Neutrophils*
- Neutrophils are involved in acute **inflammation** and primarily release **proteolytic enzymes** and reactive oxygen species, but not TNF and IL-1.
- They are crucial for initial defense against infections but do not have a significant role in producing these cytokines.
*Monocytes*
- Monocytes can differentiate into macrophages and play a role in inflammation, but they do not produce **TNF** and **IL-1** to the same extent as activated macrophages.
- Their primary function is as precursors to macrophages and dendritic cells, contributing indirectly to cytokine production.
**References:**
[1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 105-106.
Cytokines and Chemokines Indian Medical PG Question 7: Which interleukin is primarily responsible for inducing IgE production from B cells?
- A. IL-1 and IL-3
- B. IL-3
- C. IL-1
- D. IL-4 (Correct Answer)
Cytokines and Chemokines Explanation: ***IL-4***
- **IL-4** is the primary cytokine responsible for promoting B cell differentiation into **plasma cells** that produce **IgE antibodies**.
- It plays a crucial role in the development of **allergic reactions** by stimulating IgE class switching.
*IL-1*
- **IL-1** is a pro-inflammatory cytokine primarily involved in the **innate immune response**, fever, and acute phase reactions.
- It does not directly induce IgE production but can modulate immune responses in a broader context.
*IL-3*
- **IL-3** is a cytokine that primarily supports the growth and differentiation of **hematopoietic stem cells** in the bone marrow.
- It is crucial for the development of various blood cell lineages but is not directly involved in IgE class switching.
*IL-1 and IL-3*
- While both **IL-1** and **IL-3** have important roles in immunity and hematopoiesis, neither directly induces **IgE production** from B cells.
- **IL-4** is the specific and most significant interleukin for this function.
Cytokines and Chemokines Indian Medical PG Question 8: What is the primary effect of superantigens on T-cells?
- A. Polyclonal activation of T-cells leading to cytokine release (Correct Answer)
- B. Stimulation of B cells and antibody production
- C. Enhancement of phagocytosis by macrophages
- D. Activation of the complement system
Cytokines and Chemokines Explanation: ***Polyclonal activation of T-cells leading to cytokine release***
- **Superantigens** bypass the normal antigen presentation pathway by binding directly to the **MHC class II molecule** and the **T-cell receptor (TCR) beta chain**, activating a large proportion of T-cells.
- This widespread T-cell activation results in a massive release of various **cytokines**, leading to systemic inflammation and conditions like **toxic shock syndrome**.
*Stimulation of B cells and antibody production*
- While B cells can be activated, the primary and most significant effect of superantigens is on T-cells, leading to **non-specific T-cell activation**.
- Superantigen-mediated T-cell activation does not directly lead to **antigen-specific B cell activation** and **antibody production** in the same manner as conventional antigens.
*Enhancement of phagocytosis by macrophages*
- Superantigens do not primarily enhance **macrophage phagocytosis**. Their main mechanism involves direct interaction with **APC MHC class II** and **TCRs**.
- Macrophages themselves can act as **antigen-presenting cells** in the superantigen pathway, but their phagocytic function is not the main target.
*Activation of the complement system*
- The complement system is primarily activated by **antibody-antigen complexes** or directly by pathogen surfaces, not directly by **superantigens**.
- While the inflammatory response from superantigens can indirectly affect other immune components, direct activation of the complement cascade is not their primary mechanism of action.
Cytokines and Chemokines Indian Medical PG Question 9: Which of the following is the most potent stimulator of Naive T-cells?
- A. Macrophages
- B. B-cell
- C. Mature dendritic cells (Correct Answer)
- D. Follicular dendritic cells
Cytokines and Chemokines Explanation: ***Mature dendritic cells***
- **Mature dendritic cells** are the most potent professional antigen-presenting cells (APCs) for activating **naive T cells** due to their efficient antigen processing, presentation abilities, and high expression of costimulatory molecules (e.g., CD80, CD86) and MHC-peptide complexes.
- Activated by pathogens or inflammatory signals, they migrate to secondary lymphoid organs where they initiate primary immune responses by presenting antigens to and activating naive T cells.
*Follicular dendritic cells*
- **Follicular dendritic cells** primarily present intact antigens to **B cells** in germinal centers of secondary lymphoid organs, playing a crucial role in B cell maturation, selection, and antibody production.
- They lack MHC class II molecules and thus cannot directly present antigens to naive T cells.
*Macrophages*
- While **macrophages** are professional APCs, they are generally less efficient than mature dendritic cells at activating **naive T cells**, especially in the initiation of primary immune responses.
- They are more involved in presenting antigens to already activated T cells and clearing pathogens, often acting as secondary APCs.
*B-cell*
- **B cells** can act as APCs, but they are generally less efficient than **dendritic cells** in activating **naive T cells**, especially for the primary immune response.
- Their primary role in antigen presentation is to present processed antigens to **helper T cells** to receive costimulation for their own activation and differentiation into plasma cells, often after being activated themselves.
Cytokines and Chemokines Indian Medical PG Question 10: Which is the most immunogenic antigen of Salmonella Typhi?
- A. O antigen
- B. H antigen (Correct Answer)
- C. Vi antigen
- D. Somatic antigen
Cytokines and Chemokines Explanation: **Explanation:**
The immunogenicity of an antigen is determined by its chemical complexity and size. In *Salmonella Typhi*, the **H (Flagellar) antigen** is the most immunogenic because it is composed of proteins (flagellin). Proteins are more potent triggers of the immune system compared to polysaccharides, leading to a robust antibody response. This is why H-agglutinins appear earlier and reach higher titers than O-agglutinins during a *Salmonella* infection.
**Analysis of Options:**
* **A & D. O Antigen (Somatic Antigen):** These are the same entity. The O antigen is a lipopolysaccharide (LPS) located on the outer membrane. While it is important for serogrouping, polysaccharides are generally less immunogenic than proteins. O-antibodies appear later and disappear sooner than H-antibodies.
* **C. Vi Antigen:** This is a surface polysaccharide capsular antigen (Virulence antigen). It is poorly immunogenic and primarily functions by masking the O antigen from antibodies. Its main clinical utility is in identifying chronic carriers and for use in certain vaccines (e.g., Typhim VI).
**High-Yield Clinical Pearls for NEET-PG:**
* **Widal Test:** Measures antibodies against O and H antigens. A titer of **>1:160 for O** and **>1:160 for H** is usually considered significant in endemic areas.
* **Sequence of Appearance:** In Enteric fever, O antibodies appear first (around the end of the 1st week), but H antibodies reach higher peaks and persist longer.
* **Carrier State:** Persistent high titers of **Vi antibodies** (1:10 or more) suggest a chronic carrier state, as the bacteria continue to harbor the capsule in the gallbladder or urinary tract.
More Cytokines and Chemokines Indian Medical PG questions available in the OnCourse app. Practice MCQs, flashcards, and get detailed explanations.
