A basophil is a type of white blood cell present in the blood. White blood cells help protect the body against diseases and fight infections. Basophils help protect the body against disease and infections by eating some types of bacteria, foreign substances, and other cells. WHAT ARE SOME OTHER CHARACTERISTICS OF BASOPHILS?
Basophils will look black and blue or dark purple when stained by a basic dye, such as Wright stain. Dyes are colored stains that are used in laboratories, often to tell cells apart from one another. The nuclei of basophils come in various forms. The word "nuclei" means more than one nucleus. A nucleus is the center of a cell. Thus, the centers of basophils appear in various forms. A unique characteristic of basophils, compared to other white blood cells, is that they usually do not increase in numbers in response to sudden infections or diseases. However, sometimes basophils will increase in response to sudden infections or diseases.
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Basophils can also be increased due to some conditions that cause inflammation. Examples are asthma (difficulty breathing due to narrowing of the airway passage), chronic dermatitis (a long-term inflammation of the skin), and chronic inflammation of the sinuses. Sinuses are openings in the bone that often contain fluid. Another inflammatory condition that can cause an increase in basophils is Crohn's disease. Crohn's disease is a condition that causes inflammation of the intestine. The intestine is a tube shaped structure that is part of the digestive tract. It stretches from an opening in the stomach to the anus (rear end) and occupies most of the lower parts of the belly.
Hypothyroidism can cause basophils to be too high. Hypothyroidism is a condition in which the thyroid gland is underactive. The thyroid gland is a butterfly-shaped organ located in front of the neck that produces a natural chemical known as hormones that affect virtually every cell in the body and many functions such as disease fighting, heart rate, energy level, and skin condition.
Hemolytic anemia can cause an increase in basophils. Hemolytic anemia is a disorder that causes the red blood cells to be destroyed to early. Red blood cells help carry oxygen in the blood. Another cause of increased basophils is Hodgkins lymphoma, which is a painless (yet very serious), worsening condition in which lymphoid tissue is enlarged. Lymphoid tissue is a type of tissue that contains lympocytes. Lympocytes are types of white blood cells that help the body fight against disease. WHAT CAN CAUSE THE LEVEL OF BASOPHILS TO BE TOO LOW?
Basophils can be too low in people who have severe allergies. It can also be low in pregnant women and people under stress. Hyperthyroidism can also cause basophils to be too low. Hyperthyroidism is a condition in which the thyroid gland is overactive. See the previous section for a description of the thyroid gland. Basophils can be low in people who are taking corticosteroids. Corticosteroids are a group of drugs that act similarly to a natural chemical in the body known as corticosteroid hormone. Corticosteroid hormones control the body's use of nutrients and the amount of water and salts in the urine.
WHAT ARE OTHER MEANINGS OF THE TERM, BASOPHIL?
Basophil is also used to describe any type of cell with grain-like particles in the cytoplasm (the gooey substance inside of cells) that stain in a specific way when exposed to basic dyes. Dyes are colored stains that are used in laboratories, often to tell cells apart from one another. Basophil is also used as an adjective to describe parts of tissues that stain well when exposed to dyes. This meaning of basophil is also known as basophilic. WHAT ELSE ARE BASOPHILS CALLED?
Basophils are also known as a basophiles, basophilic leukocytes, basocytes, basophilocytes, and mast leukocytes.
WHAT IS THE ORIGIN OF THE TERM "BASOPHIL"?
Basophil comes from the Greek word "basis" meaning "foundation," and the Greek word "philein" meaning "to love." Put the two words together and you have "to love foundation."
WHAT CAN CAUSE THE LEVEL OF BASOPHILS TO BE TOO HIGH?
The level of basophils can be too high in response to an infection from a virus. Removal of the spleen can also cause basophils to be too high. The spleen is an organ that helps fight infection and removes and destroys worn-out red blood cells. Increased estrogen can cause basophils to be too high as well. Estrogen is a type of hormone that promotes the growth of some physical female sexual characteristics. Hormones are types of chemicals in the body that affect other cells.
Basophils can be high when inflammation in the body is healing. Basophils can also be high in diseases that cause an increase in myeloid tissue. Myeloid tissue is a type of bone marrow (a tissue found inside bones) that has many fibers. One such condition in which there is an increase in myeloid tissue is polycythemia vera. Polycythemia vera is a condition of unknown cause in which there is a long-term increase in red blood cells and other types of cells. Another such condition is myelofibrosis, in which the normal bone marrow is replaced by fibrous tissue (the connective tissue of the body). Chronic myelocytic leukemia (cancer of blood-forming tissues) can also cause a rise in basophils. Cancer is a group of diseases in which symptoms are due to an abnormal and excessive growth of cells in one of the body organs or tissues.
Another characteristic of basophiles is that their cytoplasm (a gel-like substance that fills up a cell) is mostly made of many large, rough-looking, grain-like particles. These grain-like particles can be seen under the microscope, but may sometimes cover the nucleus. The grain-like particles may decrease in numbers in response to allergic reactions and may increase in response to some types of inflammation.
The grain-like particles of basophils contain the following substances: histamine, leukotrienes, and heparin. Histamine is a substance found in all cells that is released during allergic and inflammatory reactions. Leukotrienes are substances in the body that produce allergic and inflammatory reactions, similar to histamine. Heparin is a naturally occurring substance in the body that prevents clotting (blood fluid coming together as a solid).
WHAT DOES A BASOPHIL LOOK LIKE?
A basophil looks like this under a microscope (pictured to the right):
WHAT PERCENT OF WHITE BLOOD CELLS ARE BASOPHILS?
Approximately 0.4% to 1% of white blood cells are basophils. This is the normal range of basophils on bloodwork tests. Basophils are the least common type of white blood cell.