White Blood Cell Differential Test

The White Blood Differential Test measures the percentage (and absolute values) of each type of white blood cell (WBC) that you have in your blood.
Five different types of white blood cells, also called leukocytes, normally appear in the blood:
- Neutrophils
- Lymphocytes
- Monocytes
- Eosinophils
- Basophils
The test shows if the number of cells are in proper proportion with one another, and if there is more or less of one cell type.
What do abnormal results mean?
Any infection or acute stress increases your number of white blood cells. High white blood cell counts may be due to inflammation, an immune response, or blood diseases such as leukemia. It is important to realize that an abnormal increase in one type of white blood cell can cause a decrease in the percentage of other types of white blood cells.
Although your white blood cells account for only about 1 percent of your blood, their impact is significant. White blood cells are essential for good health and protection against illness and disease. Think of white blood cells as your immunity cells. In a sense, they are continually at war. They flow through your bloodstream to battle viruses, bacteria, and other foreign invaders that threaten your health. When your body is in distress and a particular area is under attack, white blood cells rush in to help destroy the harmful substance and prevent illness. White blood cells are produced inside the bone marrow and stored in your blood and lymphatic tissues. Because some white blood cells have a short lifespan of one to three days, your bone marrow is constantly producing them.
Atypical Lymphocytes
Optimal range: 0 - 1 %
Lymphocytes are a type of white blood cell (leukocyte) involved in the immune response. Atypical lymphocytes are generally lymphocytes that have been activated to respond to a viral infection or sometimes a bacterial or parasitic infection.
A few atypical lymphocytes are probably of little clinical significance. A large number of atypical lymphocytes are often found in viral infections like mononucleosis, cytomegalovirus infections and hepatitis B. Toxoplasmosis, certain bacterial infections, medications, stress and autoimmune diseases can also be accompanied by a larger number of atypical lymphocytes.
Atypical lymphocytes can also be observed in patients with several viral infections, such as Epstein-Barr virus infection, cytomegalovirus infection, rubella, Hantavirus infection, viral hepatitis and HIV infection.
Several studies have shown that atypical lymphocytes have also been found in the peripheral blood and bronchoalveolar lavage (BAL) samples of COVID-19 patients. It may reflect the disease pathophysiology and provide important information about the diagnosis or prognosis of the disease.
LEARN MOREBand Neutrophils (%)
Optimal range: 0 - 6 %
Band neutrophils are the immature form of a white blood cell found in our bodies. All white blood cells act as a defense mechanism against stress and infection. An unusually high level of band neutrophils typically indicates the presence of a bacterial infection or inflammation of tissue.
LEARN MOREBasophils (Absolute)
Optimal range: 0 - 0.2 x10E3/uL
What are Basophils?
Basophils are a type of white blood cell. Basophils work closely with your immune system to defend your body from allergens, pathogens and parasites.
Basophils have a short life span, usually only one or two days.
Basophils are mononuclear cells, so they have one round nucleus. Basophils are also granulocytes, or white blood cells that have granules, or small particles, attached to them. These small particles are filled with enzymes, like histamine, that are released during allergic reactions. Basophils are the only white blood cells circulating around your body that contain histamine. During an allergic reaction, histamine is responsible for many of the typical symptoms of allergies, like a runny nose or sneezing.
Histamine is a vasodilator. This means it widens the blood vessels near an infection to open and allow more blood flow to the site of the infection. Heparin is a naturally occurring blood thinning substance which prevents clotting.
Basophils are responsible for the body’s immune response during allergic reactions. When the body is exposed to an allergen, basophils release histamine which triggers the physical symptoms of an allergic reaction. This causes the typical allergic reaction of running nose, watering eyes etc.
They also help to produce a crucial antibody called immunoglobulin E (IgE). Immunoglobulin attaches to basophils and a similar type of cell called mast cells. The cells then work together to release histamine and serotonin, which affects the inflammatory response to the allergen.
LEARN MOREBasophils (Percent)
Optimal range: 0 - 1 %
What are Basophils?
Basophils are a type of white blood cell. Basophils work closely with your immune system to defend your body from allergens, pathogens and parasites.
Basophils have a short life span, usually only one or two days.
Basophils are mononuclear cells, so they have one round nucleus. Basophils are also granulocytes, or white blood cells that have granules, or small particles, attached to them. These small particles are filled with enzymes, like histamine, that are released during allergic reactions. Basophils are the only white blood cells circulating around your body that contain histamine. During an allergic reaction, histamine is responsible for many of the typical symptoms of allergies, like a runny nose or sneezing.
Histamine is a vasodilator. This means it widens the blood vessels near an infection to open and allow more blood flow to the site of the infection. Heparin is a naturally occurring blood thinning substance which prevents clotting.
Basophils are responsible for the body’s immune response during allergic reactions. When the body is exposed to an allergen, basophils release histamine which triggers the physical symptoms of an allergic reaction. This causes the typical allergic reaction of running nose, watering eyes etc.
They also help to produce a crucial antibody called immunoglobulin E (IgE). Immunoglobulin attaches to basophils and a similar type of cell called mast cells. The cells then work together to release histamine and serotonin, which affects the inflammatory response to the allergen.
LEARN MOREEosinophils "Eos" (Absolute)
Optimal range: 0 - 0.4 x10E3/uL
What are Eosinophils?
Eosinophils are a type of white blood cell (leukocytes) that protect your body from parasites, allergens, foreign bacteria and outside organisms. Eosinophils are larger than most cells and make up less than 5% of all white blood cells in your body. An increased number of eosinophils may mean your body is fighting an infection or allergic reaction. Very high numbers may indicate a serious health condition.
Eosinophils have a role in defending your body from:
- fungal infections
- bacterial infections
- viral infections
- parasites, such as worms
In the immune system, eosinophils destroy invading germs like viruses, bacteria, or parasites, such as hookworms. They also have a role in the inflammatory response, especially if an allergy is involved. Eosinophils significantly contribute to inflammation related to allergies, eczema, and asthma. Inflammation helps isolate and control the immune response at an infection site but causes a side effect of tissue damage around it. Allergies are immune responses that often involve chronic inflammation.
LEARN MOREEosinophils "Eos" (Percent)
Optimal range: 0 - 6 %
What are Eosinophils?
Eosinophils are a type of white blood cell (leukocytes) that protect your body from parasites, allergens, foreign bacteria and outside organisms. Eosinophils are larger than most cells and make up less than 5% of all white blood cells in your body. An increased number of eosinophils may mean your body is fighting an infection or allergic reaction. Very high numbers may indicate a serious health condition.
Eosinophils have a role in defending your body from:
- fungal infections
- bacterial infections
- viral infections
- parasites, such as worms
In the immune system, eosinophils destroy invading germs like viruses, bacteria, or parasites, such as hookworms. They also have a role in the inflammatory response, especially if an allergy is involved. Eosinophils significantly contribute to inflammation related to allergies, eczema, and asthma. Inflammation helps isolate and control the immune response at an infection site but causes a side effect of tissue damage around it. Allergies are immune responses that often involve chronic inflammation.
LEARN MORELymphocytes "Lymphs" (Absolute)
Optimal range: 0.7 - 3.1 x10E3/uL
What are Lymphocytes and what do they do?
Lymphocytes are a type of white blood cell. They play an important role in your immune system, which helps your body fight disease and infection. Your immune system is made up of an intricate web of immune cells, lymph nodes, lymph tissue and lymphatic organs. Lymphocytes are a type of immune cell.
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.
There is also another type of lymphocyte called natural killer cells. These natural killer cells are able to destroy tumor cells without any prior activation. This is unlike the T cells which need to be activated by another immune cell.
Lymphocytes are able to remember antigens, which are foreign substances that provoke your body’s immune reaction. These include bacteria, viruses, and toxins. After an encounter with an antigen, some lymphocytes develop into memory cells. When these memory lymphocytes meet an antigen for a second time, they respond rapidly and specifically to this antigen. This is why vaccines can prevent certain disorders.
Lymphocytes survey the body’s environment, assessing potential foreign antigens from the common cold to malignancies. They interact with other cells such as phagocytes (monocytes, macrophages, histiocytes and the like) and more specialized cells called dendritic cells.
LEARN MORELymphocytes "Lymphs" (Percent)
Optimal range: 20 - 40 %
What are Lymphocytes and what do they do?
Lymphocytes are a type of white blood cell. They play an important role in your immune system, which helps your body fight disease and infection. Your immune system is made up of an intricate web of immune cells, lymph nodes, lymph tissue and lymphatic organs. Lymphocytes are a type of immune cell.
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.
There is also another type of lymphocyte called natural killer cells. These natural killer cells are able to destroy tumor cells without any prior activation. This is unlike the T cells which need to be activated by another immune cell.
Lymphocytes are able to remember antigens, which are foreign substances that provoke your body’s immune reaction. These include bacteria, viruses, and toxins. After an encounter with an antigen, some lymphocytes develop into memory cells. When these memory lymphocytes meet an antigen for a second time, they respond rapidly and specifically to this antigen. This is why vaccines can prevent certain disorders.
Lymphocytes survey the body’s environment, assessing potential foreign antigens from the common cold to malignancies. They interact with other cells such as phagocytes (monocytes, macrophages, histiocytes and the like) and more specialized cells called dendritic cells.
LEARN MOREMonocytes (Absolute)
Optimal range: 0.1 - 0.9 x10E3/uL
What are Monocytes?
Monocytes are a type of white blood cell (leukocytes) in your immune system.
Monocytes reside in your blood and tissues to find and destroy germs (viruses, bacteria, fungi and protozoa) and eliminate infected cells. Monocytes call on other white blood cells to help treat injury and prevent infection.
Monocytes turn into macrophage or dendritic cells when an invading germ or bacteria enters your body. The cells either kill the invader or alert other blood cells to help destroy it and prevent infection.
Monocytes are the largest of the white blood cells and are about twice the size of red blood cells. These powerful defenders aren’t plentiful in the bloodstream but they’re vital in protecting the body against infection.
LEARN MOREMonocytes (Percent)
Optimal range: 4 - 8 %
What are Monocytes?
Monocytes are a type of white blood cell (leukocytes) in your immune system.
Monocytes reside in your blood and tissues to find and destroy germs (viruses, bacteria, fungi and protozoa) and eliminate infected cells. Monocytes call on other white blood cells to help treat injury and prevent infection.
Monocytes turn into macrophage or dendritic cells when an invading germ or bacteria enters your body. The cells either kill the invader or alert other blood cells to help destroy it and prevent infection.
Monocytes are the largest of the white blood cells and are about twice the size of red blood cells. These powerful defenders aren’t plentiful in the bloodstream but they’re vital in protecting the body against infection.
LEARN MORENeut/Lymph Ratio
Optimal range: 0 - 2.9 Ratio
NLR (Neutrophil to Lymphocyte Ratio) is a biomarker that can be used as an indication of subclinical inflammation. NLR is a calculation based on the Absolute Neutrophil Count divided by the Absolute Lymphocyte Count determined by the peripheral blood CBC differential. This calculation, according to recent literature, is useful in assessing the likelihood of severe progression of disease in SARS-CoV-2 positive patients.
LEARN MORENeutrophils (Absolute)
Optimal range: 1.4 - 7 x10E3/uL
What are Neutrophils?
Neutrophils are the most common type of white blood cell in your body. Neutrophils grow in your bone’s soft tissue (bone marrow) and migrate through your circulation system in your blood and tissues.
Neutrophils are phagocytic, meaning that they engulf and destroy things like bacteria and viruses at the site of an injury. Like all other white blood cells, they also play a part in our body’s inflammatory response to things like allergens.
Neutrophils are clear in color. Neutrophils have a spherical shape when at rest but change shape to fight infection.
LEARN MORENeutrophils (Percent)
Optimal range: 50 - 70 %
Neutrophils are the most abundant type of white blood cell in the body. They are phagocytic, meaning that they engulf and destroy things like bacteria and viruses at the site of an injury. Like all other white blood cells, they also play a part in our body’s inflammatory response to things like allergens.
LEARN MOREPolymorphs
Optimal range: 40 - 75 %
Polymorphonuclear (PMN) cells refer to the group of white cells known as granulocytes. The three types of granulocytes are:
Neutrophils
Basophils
Eosinophils
LEARN MORESegmented Neutrophils
Optimal range: 1.5 - 8.5 cells/mcL
Neutrophils are the most abundant type of white blood cell in the found. They are phagocytic, meaning that they engulf and destroy things like bacteria and viruses at the site of an injury. Like all other white blood cells, they also play a part in our body’s inflammatory response to things like allergens.
LEARN MORESegmented Neutrophils (Percent)
Optimal range: 47 - 55 %
Neutrophils are the most abundant type of white blood cell found in the body. They are phagocytic, meaning that they engulf and destroy things like bacteria and viruses at the site of an injury. Like all other white blood cells, they also play a part in our body’s inflammatory response to things like allergens.
LEARN MORE