What do basophils do?
Basophils are a type of white blood cell (leukocyte) that plays a role in identifying and destroying bacteria and foreign proteins. Basophils work along with other white blood cells to defend against the invading microorganisms, such as bacteria, viruses and fungi.
The granules of basophils contain heparin, histamine and other molecules that play a vital role in inflammation. When activated, the basophils release chemicals from their granules that are toxic to bacteria and viruses. These chemicals kill them.
Production of basophils
Like other blood cells, basophils originate from the stem cells in the bone marrow (spongy part in the center of the long bones). Through a process called hematopoiesis, they develop different blood cells with specific structures and functions.
What are the functions of basophils?
Basophils play an important role in
Proper functioning of the immune system
Basophils are the soldiers of the immune system. In the body, they recognize the invading microorganism as a foreign body that needs to be destroyed. Basophils are the most effective in protecting the body against bacteria and parasites, including external parasites, such as ticks.
Mediating allergic reactions
Basophils along with IgE type of proteins (antibodies) mediate response to allergens. Basophils bind to immunoglobulin E (IgE), which is an antibody that protects against allergens (environmental substances, pollen proteins, parasites, ectoparasite, etc.)
Basophil activation test (BAT)
It is a specific test that helps in confirming allergic reactions. During the test, potential allergens are applied to a sample of the blood. If the person has an allergy, the basophils in their blood sample will activate specific molecules. This test is highly accurate in detecting food, drug, and venom allergies in patients.
Actions of basophils
- Histamine, the vasodilator in basophils, causes the blood vessels near the infection to widen, promoting blood flow. This helps in wound healing and destruction of germs.
- Basophils contain the anticoagulant, heparin, which prevents blood clots at the site of the infection.
- When a potentially harmful allergen enters the body, basophils respond by releasing histamine. Histamine is responsible for some of the symptoms produced by allergic reactions, such as itchy skin, watery eyes, sneezing and runny nose.
- Basophils also participate in phagocytosis, the process of destroying an invading organism (germs) by taking it apart.
- Recent studies suggest that basophils regulate T-type white blood cells and facilitate the secondary immune response.
The normal range for basophils
Basophils, eosinophils and neutrophils constitute a group of white blood cells known as granulocytes. Basophils are the least common of granulocytes and account for 0.5 to 1 percent of white blood cells.? Complete blood count (CBC) can confirm the abnormally high (basophilia) or abnormally low (basopenia) levels of basophils in the blood.
Basophilia (high basophil levels)
This may occur due to
- Hypothyroidism (underactive thyroid gland)
- Some forms of blood cancers, such as leukemia or lymphoma
- Chronic inflammation
- Myeloproliferative neoplasms (cancers of the spongy part of the bone)
- Inflammatory autoimmune disease (allergy to the body’s own protein)
- Infections including tuberculosis, ulcerative colitis, chickenpox, smallpox and influenza
- Rheumatoid arthritis
- Organ rejection
- Overproduction of white blood cells in the bone marrow
Basopenia (low basophil levels)
This may occur due to
- Hyperthyroidism (overactive thyroid gland)
- Acute inflammation and infection
- Drug-induced hypersensitivity reactions
- Severe allergy
- Urticaria (hives)
- Angioedema (swelling under the skin)
The symptoms depend on the underlying disease. Treatment is usually directed to the underlying disease that causes the change in the levels of basophils.
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