The main components of our blood include red blood cells, white blood cells, and platelets. Of these, the immunity is taken care of by white blood cells. They are extremely important in fighting the invasion of parasites, viruses, and bacteria. White blood cells may be active and alive in the bloodstream all the way from a few hours to several days.

Eosinophils are a type of white blood cell. They are present in all parts of the body, stored in the tissues. Eosinophils and white blood cells are constantly being made by the bone marrow.

The importance of eosinophils seems to be growing as research continues. Almost every function in the body relies on them in some way.

• They help attack invasions by viruses, parasites, and bacteria.
• They also have anti-allergic properties that help in the event of allergic inflammation.

An eosinophil count test or AEC test determines the number of eosinophils in the body. Through a routine blood test or alongside a Complete Blood Count (CBC), eosinophil counts can be determined very easily.

Your doctor may prescribe an AEC test report if they suspect a certain health condition. The AEC test is used for the diagnosis of the presence of health conditions and indicates whether certain viral, bacterial, or parasitic infections are present in the body. It may also be requested if your other blood reports show any abnormalities.

The AEC test is relevant in India, where Tropical Pulmonary Eosinophilia has been noticed in the coasts between Maharashtra Kerala, Tamil Nadu and West Bengal. This tropical variant presents symptoms like eosinophilia, fever, and wheezing. Although considered benign, this form is known to cause a fair amount of respiratory distress as well. Doctors may recommend the AEC test if certain other conditions are suspected to be associated with the symptoms presented.

Other Names of AEC Test

• Eosinophil count – Absolute

What Does AEC Test Measure and Who is this Prescribed For?

The AEC test measures the levels of eosinophils in the blood.

An AEC test report may be sought when there is a suspected chance of:

• Reaction to certain medication or drugs.
• Some parasitic infections.
• Severe allergic reaction.

The test can also be used as a diagnostic tool to check for the risk of:

• Vasculitis
• Acute hypereosinophilic syndrome (this is a rare leukaemia-like condition that can sometimes be fatal)
• Early signs of Addison's disease

The AEC test requires a simple collection of blood samples. It can be collected at any time of the day and does not require fasting.

AEC Test Preparation

This is a simple test that does not require too much preparation. Your blood sample may be collected at any time of the day. You can arrange to have the test taken at the doctor’s clinic, lab, or even with a home visit.

You may feel a slight sting as the needle is inserted and blood is drawn. It is also common to feel a slight throbbing sensation after the collection of blood. Both sensations subside soon after.

Before taking the ACE test, it is important to discuss your medical history with the doctor. Certain medications may cause an increase in the eosinophil count. These include:

• Laxatives contain psyllium
• Tranquillizers
• Interferon
• Some antibiotics
• Appetite suppressants or amphetamines

Your doctor will advise you on how to go about your tests if you are on similar kinds of medication. It is common to be advised to stop the medication before an ACE test temporarily.

AEC Test Inclusions: What Parameters are Included

An AEC test report only includes the count of eosinophils in the blood. It will alert you to any kinds of infections or allergens present in the body. The result of the AEC test will only give you a value of the eosinophil count, which the doctor must further interpret.

While this test can quite accurately predict the presence of certain foreign bodies and allergens, it does not indicate what kind of virus or bacteria is present in the body.

How Frequently You Should Take the AEC Test

Your doctor will ideally recommend when an AEC test report is required to make a diagnosis. It is usually prescribed when there is a doubt of infection or when certain symptoms are observed. While there is no frequency or periodicity to the test, your doctor may ask for a repeat AEC test to check how the body has responded to treatment and how well you have recovered.

Addison disease, Hypereosinophilic syndrome, Vasculitis, Eosinophilia

When a blood sample is collected, the laboratory usually checks for the number of eosinophils present in every 100 cells. This number is then multiplied by the count of white blood cells to arrive at the absolute eosinophil count. This is what the ACE results range looks like:

 *Note that different labs may have minor variations in the normal and high reference ranges

A range of factors can influence your ACE report. Here are some impacting variables:

• Low count: If the number of eosinophils in the blood is low, it could be from

• Excess cortisol: When cortisol levels are high, the immunity and eosinophils count may be lowered. This is often noticed in those who have Cushing’s syndrome.
• Alcohol: Misuse of alcohol can also compromise immunity and lower eosinophil count. It can therefore lower the body’s response to infections and disease.

In case the count is low, and there are no traces of alcohol or cortisol abnormalities, an investigation of the other white blood cell counts may also be considered. If they are normal, there is little cause for concern. However, further investigation and other tests may be required if they are not within prescribed ranges. It may be an indication of a problem with the bone marrow.

• High count: If the count is mildly high, there may be no apparent symptoms in the body. In the case of moderate or high counts, it may be an indication of a range of problems like:

• Cancers including leukaemia
• Asthma
• Allergy
• Autoimmune disease
• Hypereosinophilic syndrome – a case of high eosinophils without any allergy or parasitic infection
• Parasitic infection
• Eczema
• Reaction to medication
• Early signs of Cushing’s disease
• Lupus
• Organ transplant rejection
• Scarlet fever
• Ulcerative colitis