Differential Leukocyte Count

The Differential Basophil Count test measures the relative percentage of basophils in the blood. Basophils are spherically shaped small cells that originate from bone marrow and make up almost 1% of the total white blood cells in the body. These cells attack a foreign substance and release proteins, like histamine and heparin, to destroy harmful substances like allergens, pathogens, or parasites. Histamine helps widen the blood vessels and make space for more immune cells to come to the site of infection or injury, whereas heparin acts as a blood-thinning agent and helps avoid blood clotting at the infection or injury site.

The Differential Neutrophil Count test measures the total percentage of neutrophils in the blood. This test helps your doctor determine the underlying cause of symptoms like fever, inflammation, or infection by identifying the type of infection, i.e., bacterial or viral.

The Differential Lymphocyte Count test measures the proportion of different types of lymphocytes in the blood. Lymphocytes are a type of white blood cells that play an important role in the functioning of your immune system, which helps your body fight disease and infection. 

There are two main types of lymphocytes:

• T lymphocytes (T cells): T cells control your body’s immune system response and directly attack and kill infected cells and tumor cells.

• B lymphocytes (B cells): B cells make antibodies. Antibodies are proteins that target viruses, bacteria, and other foreign invaders.

Lymphocytes help your immune system remember every antigen (a foreign substance) it comes in contact with. After an encounter, some lymphocytes turn into memory cells. When these memory cells run into an antigen again, they recognize it and quickly respond. It is also the reason why getting vaccinated can help prevent certain diseases.

A Differential Monocyte Count test measures the relative percentage of monocytes in the blood.

Monocytes are the type of white blood cells that originate from bone marrow and travel to different tissues via blood. Once they are inside the tissue, they get converted into macrophages (a type of cell that digests harmful substances). These cells are the second line of defense in the human body after neutrophils. Monocytes are responsible for the removal of injured or dead cells, microorganisms, and other insoluble particles from the blood. 

The Differential Eosinophil Count test measures the proportion of eosinophils in relation to other types of white blood cells (WBC), such as neutrophils, lymphocytes, basophils, and monocytes. Eosinophils originate from bone marrow and have a lifespan of 8-18 hours. These cells are involved in fighting certain types of infections and responding to allergic reactions in the body. The eosinophils have varied functions that include the physiological role in organ formation, such as the development of post-gestational mammary glands. Other functions include its movement to the areas of inflammation, trapping the substances, and killing the cells with bactericidal and antiparasitic activities. It also helps in the treatment of immediate allergic reactions and modulation of inflammatory responses.