Neutrophils (also known as “segs”, “PMNs” or “polys”) are one of five types of cell belonging to the white blood cell family, called leukocytes. These include: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. All leukocytes serve in our body’s immunological and inflammatory responses, protecting us from irritants and malignant invaders. Neutrophils, along with eosinophils and basophils, constitute a group of white blood cells known as granulocytes. Normally, most of the neutrophils circulating in the bloodstream are in the mature form, with the nucleus of the cell being divided or segmented. Neutrophils are the most abundant type of white blood cell and the most abundant type of granulocytes. About 40%-60% of all white blood cells are neutrophils. Neutrophils are phagocytic; they engulf and digest other microorganisms. Neutrophil concentration is determined with a white blood cell differential, often as a part of a complete blood count (CBC). A healthcare provider may order a complete blood count during a routine health check or if someone has symptoms or signs of an infection, including:
-Fever and shaking chills
-Nausea / vomiting
1.5 – 8.5 cells/mcL
What are low values associated with?
Neutropenia, the presence of abnormally few neutrophils in the blood, is most commonly caused by cancer chemotherapy or radiation therapy. It may also point to a viral infection or a disease affecting the immune system, like HIV/AIDS. An overwhelming infection, like sepsis, that is destroying white blood cells faster than the body can produce them will also result in low neutrophil levels.
What are high values associated with?
An increased percentage of neutrophils, called neutrophilia, may result from an inflammatory disorder (rheumatoid arthritis, gout), from infection (acute or chronic), from certain cancers (myelocytic leukemia), or from stressors (eclampsia in pregnant women, injury, burns). High neutrophil count is not, in itself, a symptom-causing problem. Evaluation of neutrophils, therefore, is done to determine the condition or disorder causing the number of neutrophils to increase.