Updated December 01, 2014.
Neutrophils are just one type of cell involved in the pathophysiology of asthma.
While nearly 50% of asthma cases are due to eosinophilia and eosinophilic inflammation, this leaves a large amount of inflammation in asthma due to other causes such as neutrophils and other cell types such as:
What Do Neutrophils Do?
Neutrophils can be thought of as the foot soldiers of your immune system.
These cells are among the first type of immune cell that your body responds with to fight off an infection. As part of your immune system neutrophils attack anything your body sees as foreign such as bacteria. Neutrophils are non-specific, meaning that they do not recognize the foreign invader specifically, but recognize it as foreign (meaning it should not be there) and attack.
Neutrophils also play a significant role in asthma and other immune mediated diseases by releasing substances that can lead to bronchoconstriction and irritation of your airways.
Neutrophils And Asthma
Both the absolute number and activity of neutrophils is increased in asthma. Interestingly, the numbers of neutrophils are significantly greater in patients who demonstrate a poor response to inhaled steroids. Levels of neutrophils have been found to correlate with objective asthma outcomes such as FEV1.
Neutrophils generally increase when you encounter an allergen as part of an immune response. Your body sees the allergen as foreign and sends available neutrophils through the blood stream to destroy the allergen.
Additionally, neutrophil activation stimulates the production of more neutrophils and production of other cells through a cascade like pathway. Neutrophils also release certain substances that injure the lung, cause inflammation and lead to bronchoconstriction. In asthma your body thinks the allergens are harmful and attacks them as they would attack a bacteria or virus.
Because the lungs are a primary place where infection can enter the body, it is not surprising that large numbers are stored there ready for use. In asthma, this tends to work against you as the large number of neutrophils that react to an allergen are generating more asthma symptoms.
The immediate reaction of neutrophils in asthma is part of what is called the “early response” and is primarily due to bronchoconstriction. It may lead to acute asthma symptoms over several hours such as:
Bronchodilators tend to counter act the “early response” and provide relief of symptoms.
The immunologic response of asthma is biphasic. The “late response” begins at the same time as the “early response,” but does not lead to symptoms for several hours and is thought to be due to inflammation. Neutrophils also release substances that also contribute to the late phase. Finally, neutrophils may be responsible for mucus secretion that is part of the pathophysiology of asthma and contribute to airway remodeling.
Inhaled steroid and other maintenance medications help to prevent the “late response” and symptoms from occurring.
Pronunciation: newt-row-fils
Also Known As: white blood cell, polymorphonuclear leukocyte