Asthma Basophils and Their Role in Asthma By Pat Bass, MD Pat Bass, MD Verywell Health's LinkedIn Verywell Health's Twitter Dr. Bass is a board-certified internist, pediatrician, and a Fellow of the American Academy of Pediatrics and the American College of Physicians. Learn about our editorial process Updated on April 30, 2022 Medically reviewed by Reza Samad, MD Medically reviewed by Reza Samad, MD Reza Samad, MD, is a board-certified pulmonologist and assistant professor of medicine in New Jersey. Learn about our Medical Expert Board Print Basophils are one of the less common types of white blood cells that serve as part of our immune system. They account for only around one percent of white blood cells yet play a central role in the body's frontline defense. Westend61 / Getty Images Basophils perform a number of important functions. They produced heparin which prevents the blood from clotting too quickly and can "eat" parasites through a process called phagocytosis. But perhaps the most important role they play is in certain inflammatory reactions, particularly those involving allergies. Basophils and Allergies Basophils are a part of the innate immune system which triggers a non-specific reaction to anything the body considers harmful. Unlike adaptive immunity, which elicits a targeted response, innate immunity results in a generalized attack. When this happens, the body can experience inflammation, a form of self-protection which often manifests with swelling, pain, fever, and fatigue. In addition to this, basophils produce a substance called histamine which causes blood vessels to dilate to allow defensive immune cells closer to the site of infection. But this is not the only time when histamines are produced. When the body is exposed to certain allergens, the immune system can "over-respond" and trigger the release of histamines, causing the inflammation, sneezing, and respiratory problems we associate with allergies. Association Between Basophils and Asthma Symptoms The number of basophils in the blood can vary. When the numbers are too low, we say that the person has basopenia. When too high, the person has basophilia. Basophilia is of particular concern to people with asthma as an increase in basophil numbers can translate to an increased production of histamines. Typically speaking, basophilia is uncommon but one can occur in persons with certain bacterial or viral infections, diabetes, rheumatoid arthritis, eczema, or hypothyroidism. By virtue of the increased cell numbers, basophilia may be associated with the worsening of symptoms in persons with asthma. These can include: Severe inflammation of the lungs Narrowing of the air passages (bronchoconstriction), resulting in wheezing, chest tightness, and shortness of breath Excessive production of mucus, causing coughing and respiratory obstruction Basophilia is also commonly seen in such illnesses as atopic dermatitis, inflammatory bowel disease (IBD), hemolytic anemia, chronic myelogenous leukemia, and Hodgkin disease. Role in Managing Asthma While it remains unclear what role, if any, clinical basophil testing (BAT) may have in the diagnosis or treatment of asthma. However, it does highlight the need for further research to understand the molecular mechanisms of asthma and allergies. By doing so, new treatments and supportive therapies may be developed (including the means to temper the basophil-histamine response). What we do know is this: with appropriate treatment and the regular monitoring of a person's health, the progressive symptoms of asthma can be minimized or prevented. By contrast, poorly controlled asthma (caused either by inadequate dosing or poor treatment adherence) can lead to permanent and even debilitating lung damage. In the end, the best way to maximize asthma therapy is to maintain good health, and that includes regular visits to your healthcare provider. Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Hoffmann, J.; Knol, E.; Ferrer, L.; et al. Pros and Cons of Clinical Basophil Testing (BAT). Current Allergy and Asthma Reports. 2016;16(8):56. Siracusa, M.; Kim, B.; Spergel, J.; and Artis, D. Basophils and Allergic Inflammation. Journal of Allergy and Clinical Immunology. 2013;132(4):789-801. By Pat Bass, MD Dr. Bass is a board-certified internist, pediatrician, and a Fellow of the American Academy of Pediatrics and the American College of Physicians. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit