Leukocyte - Related Hematological Tests

What Are Leukocytes?

Leukocytes are also referred white blood cells (WBC). White blood cells are heterogeneous groups of nucleated cells produced by the bone marrow and circulate in the bloodstream.

When an individual gets infected, the white blood cells accumulate and fight against bacterial or other infections. This leads to an increased white blood cell count. However, some disorders like cancers, HIV or AIDS (human immunodeficiency virus or acquired immune deficiency syndrome), or other viral diseases attack the white blood count, causing a decrease in the count of white blood cells. In addition, some treatments like chemotherapy also result in less white blood cell count.

The main function of leukocytes is in phagocytosis and the immune system. White blood cells or leukocytes originate from the bone marrow and are produced from the bone marrow stem cells. Bone marrow is present inside the body's long bones, and it is nothing but soft spongy tissue. Two types of white blood cells called lymphocytes grow in the thymus gland, also known as T cells, and lymph nodes and spleen called B cells. The range of white blood cells in an adult male individual varies from 5000 to 11000 per microliter of blood; in female adults, it ranges from 4000 to 10000 per microliter, and in children 5000 to 11000 per microliter of blood.

What Are the Different Types of Leukocytes?

White blood cells are classified into five different types -

• Neutrophils: Neutrophils help protect the body from infections by killing bacteria, fungi, and foreign debris.

• Lymphocytes: Lymphocytes protect against viral infections and produce proteins that help fight against infection called antibodies. They are T-cells, B-cells, and natural killer cells.

• Eosinophils: They help identify and destroy parasites and cancer cells and assist basophils with their allergic response.

• Basophils: Basophils produce an allergic response like coughing, sneezing, or a runny nose to revert against the infection.

• Monocytes: They help in defending against the infection by cleaning up damaged cells.

Why Is It Indicated to Evaluate Leukocytes?

Leukocytes can be evaluated by various tests and techniques. However, a white blood count is most often used to determine and diagnose disorders associated with a high and low count of white blood cells.

The following are the disorders associated with high white blood cell count :

• The disease leads to conditions like the immune system attacking healthy tissues resulting in autoimmune or inflammatory disease.

• Bacterial or viral infections.

• Cancers such as leukemia and Hodgkin's disease.

• Allergic reactions.

• Pregnancy.

• Stress.

• Tissue damage.

• Hemorrhage.

• Leukemoid reaction.

• Surgery.

The following are the disorders associated with low white blood cell count:

• Diseases affecting the immune system, such as HIV (human immunodeficiency virus) or AIDS (acquired immunodeficiency syndrome).

• Bone marrow cancer.

• Lymphoma.

• Diseases of the liver or spleen.

• Severe infection.

• Lupus.

• Alcoholism.

• Some meditational therapy like chemotherapy or radiation therapy.

• Malaria.

A white blood cell count is performed to determine if the number of white blood cells is high or low, but it can not help confirm a diagnosis. So it is always advisable to perform along with other investigations. A complete blood count, differential, smear, or bone marrow test are some other investigations associated with low or high white blood cell count.

What Is the Procedure Required For Leukocyte Tests?

The leukocytes test is like white blood cell count, differential count, and peripheral blood smear. The procedure requires a healthcare professional or laboratory technician who will draw blood to check the white blood cell count.

This blood sample is typically taken from a vein in either arm or on the back of the hand. It only takes a few minutes to collect a blood sample and may cause minor discomfort or pain.

Following are the steps followed in the procedure of leukocytes tests -

• The healthcare professional, or the phlebotomist, first cleans the site on the arm to kill any germs with sprite or sanitizer. Then, they will tie an elastic band around the upper part of the arm. This elastic band helps the blood fill their vein by creating pressure, making it easier to collect the blood sample.

• They may insert a needle into the arms or hands to collect the blood in an attached tube. Afterward, they will open the elastic band, which is tied around the arm. Then the technician will place the gauze or a bandage on the site and apply pressure to stop the bleeding.

There is a different technique for collecting blood samples for investigation from young children and infants. This may include puncturing the skin with a lancet or a pricking needle and then using a strip or a small vial to collect the blood for further investigation. A small amount of blood sample is also efficient for children or infants.

The collected blood sample is then sent for further examination, and different types of investigation can be performed from the same blood sample.

What Is the Normal Count of Leukocytes?

The investigations involve the detection of white blood cells and disorders associated with them. The interpretation of normal results seems like this -

There are different kinds of white blood cells present in the body that work for the immune system.

• Neutrophils.

• Lymphocytes.

• Monocytes.

• Eosinophils.

• Basophils.

• Band (young neutrophils or naive neutrophils).

What Is the Risk Involved in the Investigation Performed to Detect Leukocytes?

The hematological investigation associated with white blood cells can lead to complications while performing the procedure. However, it is a commonly used technique.

The following are the risk factors involved in the blood culture test -

• Hematoma - bleeding beneath the skin.

• Excessive bleeding.

• Infections.

• Fainting or dizziness.

Conclusion -

Hematological tests associated with white blood cells are one of the most common routine tests performed for the diagnosis of blood infection. There are various disorders affecting the white blood cell count of the body by increasing or decreasing the number of cells. White blood cells play an important part in the immune system and fight against infections and inflammations. It is a sample and cost-effective procedure and helps to determine the causative agent of the infection. It is performed by an experienced healthcare provider and helps in treatment planning.