Segmented and Band neutrophiles %

ID 5. Segmented neutrophiles (NEUT) (%) and ID 9. Band neutrophiles (NEUT) (%)

Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system. They are formed from stem cells in the bone marrow and differentiated into subpopulations of neutrophil-killers and neutrophil-cagers. They are short-lived and highly mobile, as they can enter parts of tissue where other cells/molecules cannot. Neutrophils are a type of phagocyte and are normally found in the bloodstream. During the beginning (acute) phase of inflammation, particularly as a result of bacterial infection, environmental exposure, and some cancers, neutrophils are one of the first responders of inflammatory cells to migrate toward the site of inflammation. They migrate through the blood vessels and then through interstitial tissue, following chemical signals such as Interleukin-8 (IL-8), C5a, fMLP, Leukotriene B4, and H₂O₂ in a process called chemotaxis. They are the predominant cells in pus, accounting for their whitish/yellowish appearance.

Neutrophils may be subdivided into segmented neutrophils and banded neutrophils (or bands). They form part of the polymorphonuclear cells family (PMNs) together with basophils and eosinophils.

Abnormalities. Disorders or diseases caused or related.

Having an abnormally high level of neutrophils in the blood is known as neutrophilic leukocytosis, also known as neutrophilia.

Rises in neutrophil levels usually occur naturally due to infections (most likely bacterial) or injuries. However, neutrophil blood levels may also increase in response to:

-       some medications, such as corticosteroids, beta-2-agonists, and epinephrine

-       some cancers

-       physical or emotional stress

-       heart attacks

-       surgery or accidents

-       smoking or sniffing tobacco

-       pregnancy

-       obesity

-       genetic conditions, such as Down syndrome

-       surgical removal of the spleen

Some inflammatory conditions can increase neutrophil levels, including rheumatoid arthritis, inflammatory bowel disease, hepatitis, and vasculitis.

An abnormally low blood level of neutrophils is a condition called neutropenia.

A drop in neutrophil blood levels typically occurs when the body uses immune cells faster than it produces them or the bone marrow is not producing them correctly.

An enlarged spleen may also cause a decrease in neutrophil levels because the spleen traps and destroys neutrophils and other blood cells.

Some conditions and procedures that cause the body to use neutrophils too quickly include:

-       severe or chronic bacterial infections

-       allergic disorders

-       certain drug treatments

-       autoimmune disorders (including rheumatoid arthritis)

Some specific conditions, procedures, and drugs that interfere with neutrophil production include:

-       cancer

-       viral infections, such as influenza

-       bacteria infections, such as tuberculosis

-       myelofibrosis, a disorder that involves bone marrow scarring

-       vitamin B-12 deficiency

-       radiation therapy involving bone marrow

-       phenytoin and sulfa drugs

-       chemotherapy medications

-       toxins, such as benzenes and insecticides

-       aplastic anemia, when the bone marrow stops producing enough blood cells

-       severe congenital neutropenia, a group of disorders where neutrophils cannot mature

-       cyclic neutropenia, which causes cell levels to rise and fall

-       chronic benign neutropenia, which causes low cell levels for no apparent reason

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