Basophil

Basophils are a type of granulocyte, a class of white blood cells. They are the least common of all granulocytes, representing typically less than 1% of circulating white blood cells. Basophils play a role in the immune system, particularly in allergic reactions and inflammation.

Characteristics:

• Basophils are characterized by their large, darkly staining cytoplasmic granules. These granules contain a variety of substances, including histamine, heparin, chondroitin sulfate, leukotrienes, and several enzymes.
• The nucleus of a basophil is typically bilobed or irregularly shaped, but it is often obscured by the numerous granules.
• Basophils are produced in the bone marrow and circulate in the bloodstream.

Function:

• Basophils are primarily involved in the body's response to allergens and parasites.
• When an allergen binds to IgE antibodies on the surface of a basophil, it triggers the release of the contents of the granules.
• Histamine, released from the granules, causes vasodilation (widening of blood vessels) and increased permeability of blood vessels, leading to symptoms such as swelling, itching, and redness.
• Other substances released from basophil granules contribute to inflammation and the recruitment of other immune cells to the site of the reaction.
• Basophils also play a role in some inflammatory conditions, such as asthma and certain types of dermatitis.
• Heparin, another component of the granules, acts as an anticoagulant.

Clinical Significance:

• An elevated basophil count in the blood (basophilia) can be associated with a variety of conditions, including allergic reactions, parasitic infections, myeloproliferative disorders (such as chronic myelogenous leukemia), and hypothyroidism.
• A low basophil count (basopenia) is more difficult to detect and is often of less clinical significance, although it can sometimes be seen in acute infections or after corticosteroid use.
• Specific testing is needed to determine the cause of abnormal basophil counts.