Mast cells

The Pathology Dictionary Team
March 21, 2023

What are mast cells?

Mast cells are a type of white blood cell (WBC) that are involved in the body’s immune response. Mast cells are similar in appearance to basophils, with both types of cells containing large granules in their cytoplasm (body of the cell), but they originate from different cell lines and can be found in different locations throughout the body.

What do mast cells do?

Mast cells play a critical role in the body’s defense against parasites and in allergic reactions. When activated by various triggers, such as allergens, pathogens, or physical injury, mast cells release a range of potent mediators, including histamine, proteases, cytokines, and chemokines, into the surrounding tissues.

Histamine is a potent vasodilator that increases blood flow and permeability in the surrounding tissues, allowing immune cells and other molecules to access the site of infection or inflammation. Histamine can also cause the characteristic symptoms of an allergic reaction, such as itching, swelling, and bronchoconstriction.

Mast cells also play a role in the recruitment and activation of other immune cells, such as eosinophils and T cells, to the site of inflammation. Additionally, they have been implicated in the regulation of angiogenesis (the formation of new blood vessels), tissue repair, and even in the maintenance of homeostasis.

Where are mast cells normally found?

Mast cells are widely distributed in the body, especially in tissues that come into contact with the external environment, such as the skin, respiratory and digestive tracts.

What diseases are associated with mast cells?

While mast cells are important for the body’s immune response, their activation can also contribute to the development of various diseases, such as allergies, asthma, inflammatory bowel disease, and autoimmune disorders.