What is the difference between a polymorphonuclear cell (PMN) and a neutrophil?

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From the Research

Polymorphs and neutrophils are actually the same type of white blood cell, with "polymorph" being a shortened term for "polymorphonuclear leukocyte," which refers to neutrophils due to their multi-lobed nucleus. Neutrophils are the most abundant white blood cells in human blood, making up 50-70% of all circulating white blood cells 1. They serve as the body's first line of defense against bacterial and fungal infections through phagocytosis (engulfing and destroying pathogens) and by releasing antimicrobial substances. These cells are characterized by their rapid response to infection, typically arriving at sites of inflammation within minutes. Neutrophils have a short lifespan of only 1-2 days in circulation. In clinical settings, elevated neutrophil counts (neutrophilia) often indicate bacterial infection, inflammation, or stress, while decreased counts (neutropenia) can suggest bone marrow disorders, viral infections, or medication side effects.

Some key points to consider about neutrophils include:

  • Their role in immune system homeostasis and shaping the host response to infection 2
  • Their ability to phagocytose and kill prokaryotic and eukaryotic organisms very efficiently 3
  • Their potential to contribute to autoimmune and inflammatory disease when activated inappropriately or dysregulated 3
  • Their short lifespan and rapid response to infection, making them a crucial part of the body's defense mechanism 1

When reviewing blood test results, the terms "polymorph" and "neutrophil" can be used interchangeably, as they refer to the same cell type. It is essential to consider the context and the patient's overall clinical presentation when interpreting these results. The most recent and highest quality study on neutrophil biology, published in 2021, provides a comprehensive overview of their role in the immune system and their potential impact on various diseases 3.

References

Research

The Role of Neutrophils in the Immune System: An Overview.

Methods in molecular biology (Clifton, N.J.), 2020

Research

The Neutrophil.

Immunity, 2021

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This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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