Absolute Eosinophil Count Test

Absolute Eosinophil Count Test

It is a simple blood test that measures eosinophils level in the blood. Eosinophils are one type of white blood cells (also called WBCs) present in the body. The other types of WBCs present are neutrophils, lymphocytes, basophils and monocytes.

Eosinophils are produced in the bone marrow and then transported throughout the body to various tissues in the blood. The main purpose of eosinophils is to fight and protect the body against various parasites, viruses and bacteria. They do so by releasing granules of enzymes against foreign organisms. Eosinophils also play a role in the inflammatory response of our body, by isolation and limiting a diseased part.

Eosinophils constitute 0-6% of total white blood cells. When the levels of eosinophils are high in blood it is known as eosinophilia. It is present when levels are more than 500/microliter. When levels of eosinophils are persistently more than 1500/microliter when tested 1 month apart, with increased bone marrow and tissue eosinophils, it is called hypereosinophilia. Treatment of eosinophilia is to find and treat the root cause of high eosinophils levels.

Why is the Absolute Eosinophil Count Test prescribed?

Your healthcare provider may prescribe absolute eosinophil count when he suspects high levels of eosinophils (eosinophilia) in certain conditions like:

• Parasitic infestation especially with roundworm
• Allergic disorders like asthma, hay fever, eczema
• Crohn’s disease/ulcerative colitis
• Malignancy like leukaemia and Hodgkin’s lymphoma
• Allergy to certain drugs
• Hypereosinophilic syndrome
• Fungal infection
• Low levels of eosinophils is seen in conditions like alcohol abuse and Cushings disease

Sometimes this test is also advised if there are abnormal eosinophil count results of routine differential counts.

What are components of Absolute Eosinophil Blood Test?

Absolute eosinophil count is calculated by multiplying the percentage of eosinophils with the total white blood cell count. The percentage of eosinophils is found by lab technicians by counting the number of eosinophils in 100 white blood cells.

Procedure and Prerequisites

The sample for absolute eosinophil blood test is taken from blood by inserting a small needle into the vein of your arm. A small amount of blood is then collected in a test tube or vial. You may feel a little pain due to needle prick. You may resume your daily activities immediately. Certain medications can alter the eosinophil count levels so consult with doctor before undergoing this test

Reference range

Normal range : 20 - 500/microliters