Basophils are a type of white blood cell (leucocyte). They are produced in the bone marrow but can be found in various tissues around the body. White blood cells are part of the immune system and contribute to its normal function. Basophils make up approximately 1% or less of the total white blood cell count. However, this figure can increase or decrease in certain diseases.
Why Take A Basophils Blood Test?
Because basophils are part of the immune system, they are a good marker for infection or inflammation. Basophils accumulate during many illnesses and conditions including autoimmunity, cancer, allergic diseases and organ rejection.
Basophils are a major factor in the human body’s allergic response. For example, the basophil activation test (BAT) has been used to detect allergic reactions to food, drugs and venom.
A blood test containing a basophil count can help to identify if the body has initiated an immune response. Because basophils are a marker for infection, too, they are also useful to identify injuries that may have resulted in inflammation.
What Function Do Basophils Have In The Body?
Basophils are a type of white blood cell. They are a form of granulocyte because they contain granules comprising of disease-fighting substances, including:
- Platelet-activating factor
When an infection occurs within the body, basophils are released from the bone marrow and travel to the infection site. The substances they contain help the body to deal with allergens and inflammation. For example:
- Basophils release heparin, an anticoagulant, which prevents blood from clotting too quickly
- Histamine increases the permeability of capillaries allowing white blood cells and proteins to pass freely, enabling them to engage with pathogens at the infection site
- Histamine is a central mediator of itching
Basophils also have receptors on their surface which bind to an immunoglobulin called IgE. IgE is a Y shaped protein produced by plasma cells and the immune system to neutralise pathogens like bacteria and viruses.
How Do Changes In Basophils Affect Health And Wellbeing?
Because basophils are a marker for infection or inflammation there may be signs of weakness, tiredness, fever, weight loss and painful joints. If the immune system is already compromised and fighting an infection, it is common for other infections to invade such as coughs and colds.
Allergies, on the other hand, can affect your everyday life such as asthma, but most are mild and are able to be kept under control. However, severe reactions are uncommon but can sometimes occur. Basophils are primary effector cells in allergic disorders like hay fever, asthma and anaphylaxis.
What Can Cause Basophils To Change?
Allergies are caused by the body’s immune system identifying a certain substance as if it is harmful. The mechanism behind this is not exactly known, but the number of individuals with an allergy is increasing yearly.
When a pathogen or a ‘harmful’ substance enters the body, basophils are released from the bone marrow. Once activated, they degranulate to release the substances they contain, contributing to an inflammatory response. They have a relatively short lifespan of up to 1-2 days.
What Are The Most Common Symptoms?
Basophils are implicated in food allergies and allergic reactions to food are the most common cause of anaphylaxis. The common symptoms of anaphylaxis are:
- Feeling faint or lightheaded
- Difficulty breathing
- Fast heartbeat
- Clammy skin
- Collapse or losing consciousness
Anaphylaxis is a life-threatening condition and is a medical emergency. It needs to be treated quickly.
Asthma affects approximately 300 million people worldwide and is the most common chronic disease in childhood. The most common asthma symptoms are:
- Tight chest
Basophils are thought to have a variety of roles in inflammatory skin diseases such as urticaria and atopic dermatitis. Urticaria is more commonly known as hives, weals, welts or nettle rash and is characterised by a raised itchy rash on the skin.
How To Keep Basophils In The Healthy Range
Basophils are an important part of the immune system and although they are the least abundant, they are the largest granulocyte. Although you may not be able to directly influence your basophil count, there are some steps you can take to keep your immune system healthy.
Nutrition is an important aspect of our immune status and deficiency in some nutrients can weaken the system. It is essential to eat a healthy, balanced diet incorporating the following macronutrients: zinc,
selenium, iron, copper, vitamins A, C, E and B6, and folic acid. 
Smoking has also been implicated in damaging the immune system. Therefore, it is important to stop smoking if you currently do, particularly as the damage is reversible if you quit.
Exercise is key to a healthy lifestyle. However, participating in intense exercising can cause immunodepression during recovery. One exercise bout can cause changes to the white blood cell composition which can remain even during recovery. Therefore, it is essential to have sufficient rest between exercise sessions to prevent illness and injury.
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