Are your blood test results showing high levels of eosinophils? Let's learn about eosinophils in a simple way!

Have you ever looked at a Full Blood Count Report and wondered, "What is this?" Among those names, you may have seen the name "Eosinophils." Sometimes the doctor might say, "Oh... the eosinophil count is a bit high, isn't it?" So we wonder, "Who are these eosinophils? What happens when that number increases?" That's the answer to that question that we are going to discuss in this article today, very simply and in a friendly manner.

So, who are these eosinophils? What is their function?

Simply put, Eosinophils are a type of white blood cell in our body. Imagine that our body is like a country. Then there is an army that protects that country. That is what our body's immune system is like. White blood cells are the specially trained soldiers in this immune system.

There are different groups of white blood cells in this army. That is, like the army, the navy, and the air force. Similarly, our white blood cells are divided into three main types. Those are the types called `(granulocytes)`, `(lymphocytes)`, and `(monocytes)`. Here, a special force in the `(granulocytes)` group is called Eosinophils.

Now let's see what their main duties are:

• Fighting parasites: When parasitic infections like worms enter our bodies, these eosinophils are the first to come forward to fight them. Like a special commando force. Their cells contain small granules containing toxic proteins. When an invader comes, these granules explode and destroy the parasite with the toxins. For example, they are very active in infections like pinworms.
• Activation in allergies: Do you have an allergy to dust, food, or pollen? These eosinophils become very active during allergic reactions. Their activity also affects the swelling, redness, and itching of various parts of the body due to allergies.
• Attacking certain types of bacteria: Some types of bacteria can hide inside our body's cells and cause disease. Eosinophils also help to find and destroy such enemies.

Where are these Eosinophils in our body? How can we see them?

Eosinophils are produced in the bone marrow inside our bones. It's like a military training school. After they mature, they enter the blood and circulate throughout the body. But they live most of the time in our body's tissues.

The most common places to see them are:

• Blood
• Bone marrow
• Lungs
• Skin
• Stomach and gut
• Adipose tissue

You might be wondering how they look. They are really small. They can only be seen with a microscope. Normally, these cells are colorless. But when you add a special dye to them in the lab, they turn a beautiful pink or purple color. They are a little bigger than other cells. Their nucleus is very special. It looks like two drops of water connected by a small string.

What is the normal number of eosinophils?

Eosinophils typically make up less than 5% of the total white blood cells in the blood of a healthy adult. In terms of values, a normal level is between 30 and 350 cells per microliter of blood .

But remember, there's nothing to be afraid of if this number is slightly low in a blood report you did once. Because other cells in our immune system work to compensate for that deficiency. But if this number continues to be low, it's important to talk to a doctor about it.

Most of the time, our focus is on an increase in the number of eosinophils. We call this ``(Eosinophilia)``. There are three levels of this.

What medical conditions can cause changes in eosinophil counts?

There are a number of reasons why eosinophil counts can fluctuate from normal levels. Let's take a look at what they are.

Decreased eosinophil count (Eosinopenia)

This is a very rare condition. A lower than normal number of eosinophils is called ``Eosinopenia``. There are two main reasons for this:

• Cushing's syndrome: A condition caused by the body's overproduction of the hormone cortisol. When this hormone increases, the number of eosinophils can decrease.
• Sepsis: A serious condition in which an infection causes severe inflammation and blood clotting throughout the body.

But as mentioned before, a temporary decrease in eosinophil count is not a major health risk.

Increased eosinophil count (Eosinophilia)

This is the condition we see and talk about all the time. There are many reasons why eosinophil counts can increase. Sometimes these increased eosinophil cells can accumulate in different parts of the body and cause problems.

• Eosinophilic Gastrointestinal Disorders (EGID): This is the most common condition. What happens here is that a large number of eosinophil cells stick to the walls of the digestive tract (esophagus, stomach, intestines) and cause them to swell. For example, if this happens in the esophagus, it is called `(eosinophilic esophagitis)`. This can cause symptoms such as difficulty swallowing and stomach pain.
• Eosinophilic Lung Disorders: Eosinophil cells accumulate in the lungs and cause inflammation. This is similar to severe asthma. Symptoms such as shortness of breath and coughing may occur.
• Eosinophilic Blood and Tissue Disorders: Sometimes these cells can damage the tissues under the skin, blood vessels, and vital organs like the heart and kidneys.

What are the signs that indicate a change in eosinophil count?

Symptoms of eosinophil-related diseases usually appear in relation to the area where the cells accumulate and cause damage. However, there are several common symptoms that can be seen.

• Coughing and difficulty breathing
• Stomach aches and pains
• Fatigue
• Skin rashes and sores (Rash)
• Pus-filled blisters on the skin
• Inflammation in the body

What causes these conditions?

Here are some of the main reasons why eosinophil counts increase:

• Allergies: Allergies to dust, pollen, and certain foods.
• Parasitic infections: especially worm infections.
• Skin diseases: Conditions such as eczema and rashes.
• Asthma: Eosinophil counts may be elevated in asthmatic patients.
• Reactions to some medications.
• Some types of cancer: But this is very rare.

What tests are done to detect these?

If your doctor suspects an eosinophil count abnormality, the first thing they will do is do a full blood count (FBC) . This will check your white blood cell count and eosinophil percentage.

In addition, further tests can be done to find the exact cause.

• Absolute Eosinophil Count: This is also a blood test. However, it can detect not only the Eosinophil percentage, but also the actual number of Eosinophil cells in the blood.
• Bone Marrow Biopsy: This is not a routine procedure. If the eosinophil count is very high or if another serious condition is suspected, a small sample of bone marrow is taken and tested.
• Other tests: Depending on your symptoms, a stool sample (to check for worm eggs), a chest X-ray, or a tissue biopsy may be done.

Can an increased eosinophil count be a sign of cancer?

This is a question that many people are afraid of. In fact, very rarely, a persistently high eosinophil count can be a sign of certain types of cancer. For example, this condition can be seen in blood cancers such as Hodgkin lymphoma, or cancers of the breast, cervix, or colon.

What are the treatments for these conditions?

Treatment depends on the underlying cause of the change in eosinophil count.

Treatment for high eosinophil counts

• Treating the Cause: If the cause is a worm infestation, the eosinophil count will return to normal after deworming. If the cause is an allergy, this can be controlled by avoiding the allergen (e.g., food, dust) and using allergy medications.
• Anti-inflammatory medications: If eosinophil cells are causing tissue damage, medications such as steroids (corticosteroids) are given to control the condition.

Treatment for low eosinophil counts

Usually, this does not require any special treatment. The body will correct this condition on its own. If the cause is something like alcohol consumption, it is important to stay away from that habit.

How do we keep our Eosinophil cells healthy?

The same things we do to keep our entire immune system healthy are also beneficial for the health of eosinophil cells.

• Take care of cleanliness: Frequent hand washing, clean water, and eating clean food can help prevent parasitic infections.
• Eat a balanced diet: Eating a well-balanced diet strengthens the immune system. It is also important to cook your food well.
• Avoid things that are bad for you: Stay away from foods, drinks, or other things that you are allergic to.
• Limit alcohol consumption.