Polymorphonuclear Cells (PMNs) and Neutrophils: Relationship and Terminology
Yes, polymorphonuclear cells (PMNs) are essentially the same as neutrophils in clinical practice and literature. The terms are used interchangeably in medical contexts, with PMN being a descriptive term referring to the multi-lobed nucleus characteristic of neutrophils 1.
Terminology and Classification
- Neutrophils are specifically referred to as polymorphonuclear neutrophils (PMNs) due to their distinctive multi-lobed nuclear morphology 2, 3
- PMNs are the most abundant type of granulocytes in the blood and serve as primary professional phagocytes in the immune system 4, 5
- In laboratory reports and clinical settings, the terms "polys," "PMNs," and "neutrophils" all refer to the same cell type 1, 3
Functional Characteristics
- PMNs/neutrophils are the first and most lethal effector cells recruited to inflammation sites 1
- They perform critical immune functions including phagocytosis, oxidative burst production, and release of antimicrobial substances 5
- These cells are essential for defense against bacterial and fungal infections 3
- PMNs/neutrophils can both protect tissues and potentially cause tissue damage through their potent inflammatory actions 2, 5
Distinction from Other Cell Types
- While PMNs generally refer to neutrophils, it's important to note that in specialized immunology contexts, there are distinctions between neutrophils and other similar cells 1
- In cancer and chronic inflammation research, there's a distinction between neutrophils and polymorphonuclear-myeloid-derived suppressor cells (PMN-MDSCs), though they share similar morphology 1
- The separation between neutrophils and PMN-MDSCs requires specialized techniques like gradient centrifugation, as they cannot be distinguished by standard markers alone 1
Clinical Relevance
- In standard clinical practice and most medical contexts, "poly" and "neutrophil" refer to the same cell 1
- Neutrophils/PMNs are critical in inflammatory responses and are often the first immune cells to respond to infection 6
- Elevated neutrophil/PMN counts typically indicate acute infection or inflammation 1
- These cells form a crucial part of the innate immune system and help bridge to adaptive immunity 2, 6
Special Considerations
- In specialized research contexts, particularly in cancer immunology, more nuanced distinctions exist between different types of polymorphonuclear cells 1
- The term PMN may sometimes encompass other granulocytes with multi-lobed nuclei, but in routine clinical practice, it almost always specifically refers to neutrophils 1, 3