Macrophages are a type of white blood cell that are part of your body's defense mechanism and also part of the immune response in asthma. They are made in your bone marrow. When a foreign invader, like bacteria, enter your blood stream, macrophages secrete certain substances in a battle to help kill the bacteria.
In asthma, macrophages release substances that initiate and prolong hyper-responsiveness of the airways, increase mucus production and swelling, and recruit eosinophils to the lung. These substances include:
- Platelet activating factor
Macrophage comes from Macro meaning "large" and Phage meaning "to eat." When a macrophage encounters something foreign, it tends to surround it and destroy it.