Cytokines is secreted by, EXCEPT?

PGIMS Rohtak NO - 2017

Applied Physiology

Easy

Appeared in: PGIMS Rohtak NO - 2017

Explanation

Red Blood Cells (RBCs) are the correct answer because they are the only cells listed that do not secrete cytokines.
Mature RBCs are anucleated (lack a nucleus) and do not have organelles like ribosomes or endoplasmic reticulum.
These organelles are essential for synthesizing proteins, and cytokines are a type of protein.
The primary function of RBCs is to transport oxygen and carbon dioxide, not to participate in immune signaling through cytokine secretion.

Option B: Neutrophils are a major component of the innate immune system and are well-known for secreting pro-inflammatory cytokines to recruit other immune cells and fight infection.
Option C: B-Lymphocytes are key cells of the adaptive immune system that, in addition to producing antibodies, secrete various cytokines like TNF and chemokines to regulate immune responses.
Option D: Mast cells are tissue-resident immune cells famous for their role in allergic reactions. They release a variety of potent mediators upon activation, including numerous cytokines like TNF-α and interleukins.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cellular sources of cytokine secretion as background academic context rather than a clinical decision trigger.
Understanding which cells produce cytokines is fundamental for nurses to comprehend the pathophysiology of inflammation, infection, and autoimmune diseases.
Nurses monitor for clinical signs of systemic inflammation (e.g., fever, tachycardia, elevated C-reactive protein), which are directly driven by the release of cytokines from immune cells.
What if a patient is experiencing a 'cytokine storm' as seen in sepsis or severe viral infections? The nurse's priority is to monitor for signs of multi-organ dysfunction (e.g., ARDS, hypotension, acute kidney injury) and be prepared to administer prescribed immunosuppressive therapies to control the overwhelming inflammatory response.

How to Approach the Question

First, identify the keyword 'EXCEPT' in the question. This signals that you must find the option that does not fit the given condition.
The core concept is 'cytokine secretion'. Cytokines are signaling proteins used by the immune system.
Review the function of each cell type listed in the options.
Neutrophils, B-Lymphocytes, and Mast cells are all types of immune cells (or closely related). Immune cells are expected to communicate and signal, making cytokine secretion a likely function.
Consider the Red Blood Cell (RBC). Its primary function is gas transport.
Recall the unique structure of a mature RBC: it lacks a nucleus and other organelles required for protein synthesis. Since cytokines are proteins, an RBC cannot produce them. This makes it the logical exception.

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