Blood Differential Test

Blood Differential Test

Blood Differential Test

What is a blood differential test?

The blood differential test can detect abnormal or immature cells. It can also diagnose an infection, inflammation, leukemia, or an immune system disorder.

Type of white blood cellFunction
neutrophilhelps stop microorganisms in infections by eating them and destroying them with enzymes
lymphocyte–uses antibodies to stop bacteria or viruses from entering the body (B-cell lymphocyte)
–kills off the body’s cells if they’ve been compromised by a virus or cancer cells (T-cell lymphocyte)
monocytebecomes a macrophage in the body’s tissues, eating microorganisms and getting rid of dead cells while increasing immune system strength
eosinophilhelps control inflammation, especially active during parasite infections and allergic reactions, stops substances or other foreign materials from harming the body
basophilproduces enzymes during asthma attacks and allergic reactions

The blood differential test can detect abnormal or immature cells. It can also diagnose an infection, inflammation, leukemia, or an immune system disorder.


Why do I need a blood differential test?

Your doctor may order a blood differential test as part of a routine health exam. A blood differential test is often part of a complete blood count (CBC). A CBC is used to measure the following components of your blood:

  • white blood cells, which help stop infections
  • red blood cells, which carry oxygen
  • platelets, which help clot the blood
  • hemoglobin, the protein in red blood cells that contains oxygen
  • hematocrit, the ratio of red blood cells to plasma in your bloodA blood differential test is also necessary if your CBC results are not within the normal range. Your doctor may also order a blood differential test if they suspect that you have an infection, inflammation, bone marrow disorder, or autoimmune disease.

How is a blood differential test performed?

Your doctor checks your white blood cell levels by testing a sample of your blood. This test is often performed at an outpatient clinical laboratory. The healthcare provider at the lab uses a small needle to draw blood from your arm or hand. No special preparation before the test is necessary.

A laboratory specialist puts a drop of blood from your sample on a clear glass slide and smears it to spread the blood around. Then, they stain the blood smear with a dye that helps to differentiate the types of white blood cells in the sample. The lab specialist then counts the number of each white blood cell type.

The specialist may do a manual blood count, visually identifying the number and size of cells on the slide. Your specialist might also use an automated blood count. In this case, a machine analyzes your blood cells based on automated measurement techniques. Automated count technology uses electrical, laser, or photodetection methods to provide a highly accurate portrait of the size, shape, and number of blood cells in a sample. A 2013 study showed that these methods are very accurate, even across different types of machines that do automatic blood counts.

Eosinophil, basophil, and lymphocyte count levels might not be accurate if you’re taking corticosteroid medications, such as prednisone, cortisone, and hydrocortisone, at the time of the test. Let your doctor know if you’re taking any of these medications before taking the test.

What are the complications associated with a blood differential test?

The risk of complications from having blood drawn is very slight. Some people experience mild pain or dizziness. After the test, a bruise, slight bleeding, an infection, or a hematoma (a blood-filled bump under your skin) might develop at the puncture site.

What do the test results mean?

Intense exercise, and high levels of stress can affect your white blood cell count, especially your neutrophil levels. Some studies show that a vegan diet can cause your white blood cell count to be lower than normal. However, the reason for this isn’t agreed upon by scientists.

An abnormal increase in one kind of white blood cell can cause a decrease in another kind. Both abnormal results can be due to the same underlying condition.

Lab values may vary. According to the American Academy of Pediatric Dentistry, the percentages of white blood cells in healthy people are as follows:

  • 54 to 62 percent neutrophils
  • 25 to 30 percent lymphocytes
  • 0 to 9 percent monocytes
  • 1 to 3 percent eosinophils
  • 1 percent basophils
    An increased percentage of neutrophils in your blood can mean that you have:
  • neutrophilia, a white blood cell disorder that can be caused by an infection, steroids, smoking, or rigorous exercise
  • an acute infection, especially a bacterial infection
  • acute stress
  • pregnancy
  • inflammation, such as inflammatory bowel disease or rheumatoid arthritis
  • tissue injury due to trauma
  • chronic leukemia
    A decreased percentage of neutrophils in your blood can indicate:
  • neutropenia, a white blood cell disorder that can be caused by a lack of neutrophil production in the bone marrow
  • aplastic anemia, a decrease in the number of blood cells produced by your bone marrow
  • a severe or widespread bacterial or viral infection
  • recent chemotherapy or radiation therapy treatments
    An increased percentage of lymphocytes in your blood may be due to:
  • lymphoma, a white blood cell cancer that starts in your lymph nodes
  • a chronic bacterial infection
  • hepatitis
  • multiple myeloma, a cancer of the cells in your bone marrow
  • a viral infection, such as mononucleosis, mumps, or measles
  • lymphocytic leukemia
    A decreased percentage of lymphocytes in your blood can be a result of:
  • bone marrow damage due to chemotherapy or radiation treatments
  • HIV, tuberculosis, or hepatitis infection
  • leukemia
  • a severe infection, such as sepsis
  • an autoimmune disorder, such as lupus or rheumatoid arthritis
    A heightened percentage of monocytes in your blood can be caused by:
  • chronic inflammatory disease, such as inflammatory bowel disease
  • a parasitic or viral infection
  • a bacterial infection in your heart
  • a collagen vascular disease, such as lupus, vasculitis, or rheumatoid arthritis
  • certain types of leukemia
    An increased percentage of eosinophils in your blood can indicate:
  • eosinophilia, which can be caused by allergic disorders, parasites, tumors, or gastrointestinal (GI) disorders
  • an allergic reaction
  • skin inflammation, such as eczema or dermatitis
  • a parasitic infection
  • an inflammatory disorder, such as inflammatory bowel disease or celiac disease
  • certain cancers
    An increased percentage of basophils in your blood might be caused by:
  • a serious food allergy
  • inflammation
  • leukemia

    What happens after the blood differential test?

    Your doctor will likely order more tests if you have a persistent increase or decrease in the levels of any of the
    listed types of white blood cells. These tests can include a bone marrow biopsy to determine the underlying cause.

Your doctor will discuss management options with you after identifying the cause of your abnormal results. They may also order one or more of the following tests to determine the best options for your treatment and follow-up:

  • eosinophil count test
  • flow cytometry, which can tell if a high white blood cell count is caused by cancers of the blood
  • immunophenotyping, which can help find the best treatment for a condition caused by abnormal blood cell counts
  • polymerase chain reaction (PCR) test, which measures biomarkers in bone marrow or blood cells, especially blood cancer cellsOther tests might be necessary based on the results of the differential test and follow-up tests. Your doctor has many ways of determining and treating causes of abnormal blood cell counts, and your quality of life will likely remain the same, if not improve, once you find the cause.

Source: Click This Link

What is Blood?

Blood is a constantly circulating fluid providing the body with nutrition, oxygen, and waste removal. Blood is mostly liquid, with numerous cells and proteins suspended in it, making blood "thicker" than pure water. The average person has about 5 liters (more than a gallon) of blood.

About Blood Donation

A blood donation occurs when a person voluntarily has blood drawn and used for transfusions and/or made into biopharmaceutical medications by a process called fractionation (separation of whole-blood components). Donation may be of whole blood (WB), or of specific components directly (the latter called apheresis). Blood banks often participate in the collection process as well as the procedures that follow it.

More Facts

A liquid called plasma makes up about half of the content of blood. Plasma contains proteins that help blood to clot, transport substances through the blood, and perform other functions. Blood plasma also contains glucose and other dissolved nutrients.

About half of blood volume is composed of blood cells:

• Red blood cells, which carry oxygen to the tissues
• White blood cells, which fight infections
• Platelets, smaller cells that help blood to clot

Blood is conducted through blood vessels (arteries and veins). Blood is prevented from clotting in the blood vessels by their smoothness, and the finely tuned balance of clotting factors.

Blood Conditions

Hemorrhage (bleeding): Blood leaking out of blood vessels may be obvious, as from a wound penetrating the skin. Internal bleeding (such as into the intestines, or after a car accident) may not be immediately apparent.

Hematoma: A collection of blood inside the body tissues. Internal bleeding often causes a hematoma.

Leukemia: A form of blood cancer, in which white blood cells multiply abnormally and circulate through the blood. The abnormal white blood cells make getting sick from infections easier than normal.

Multiple myeloma: A form of blood cancer of plasma cells similar to leukemia. Anemia, kidney failure and high blood calcium levels are common in multiple myeloma.

Lymphoma: A form of blood cancer, in which white blood cells multiply abnormally inside lymph nodes and other tissues. The enlarging tissues, and disruption of blood's functions, can eventually cause organ failure.

Anemia: An abnormally low number of red blood cells in the blood. Fatigue and breathlessness can result, although anemia often causes no noticeable symptoms.

Hemolytic anemia: Anemia caused by rapid bursting of large numbers of red blood cells (hemolysis). An immune system malfunction is one cause.

Hemochromatosis: A disorder causing excessive levels of iron in the blood. The iron deposits in the liver, pancreas and other organs, causing liver problems and diabetes.

Sickle cell disease: A genetic condition in which red blood cells periodically lose their proper shape (appearing like sickles, rather than discs). The deformed blood cells deposit in tissues, causing pain and organ damage.

Bacteremia: Bacterial infection of the blood. Blood infections are serious, and often require hospitalization and continuous antibiotic infusion into the veins.

Malaria: Infection of red blood cells by Plasmodium, a parasite transmitted by mosquitos. Malaria causes episodic fevers, chills, and potentially organ damage.

Thrombocytopenia: Abnormally low numbers of platelets in the blood. Severe thrombocytopenia may lead to bleeding.

Leukopenia: Abnormally low numbers of white blood cells in the blood. Leukopenia can result in difficulty fighting infections.

Disseminated intravascular coagulation (DIC): An uncontrolled process of simultaneous bleeding and clotting in very small blood vessels. DIC usually results from severe infections or cancer.

Hemophilia: An inherited (genetic) deficiency of certain blood clotting proteins. Frequent or uncontrolled bleeding can result from hemophilia.

Hypercoaguable state: Numerous conditions can result in the blood being prone to clotting. A heart attack, stroke, or blood clots in the legs or lungs can result.

Polycythemia: Abnormally high numbers of red blood cells in the blood. Polycythemia can result from low blood oxygen levels, or may occur as a cancer-like condition.

Deep venous thrombosis (DVT): A blood clot in a deep vein, usually in the leg. DVTs are dangerous because they may become dislodged and travel to the lungs, causing a pulmonary embolism (PE).

Myocardial infarction (MI): Commonly called a heart attack, a myocardial infarction occurs when a sudden blood clot develops in one of the coronary arteries, which supply blood to the heart.

Source: WebMD

Today in the developed world, most blood donors are unpaid volunteers who donate blood for a community supply. In some countries, established supplies are limited and donors usually give blood when family or friends need a transfusion (directed donation). Many donors donate as an act of charity, but in countries that allow paid donation some donors are paid, and in some cases there are incentives other than money such as paid time off from work. Donors can also have blood drawn for their own future use (autologous donation). Donating is relatively safe, but some donors have bruising where the needle is inserted or may feel faint.

Potential donors are evaluated for anything that might make their blood unsafe to use. The screening includes testing for diseases that can be transmitted by a blood transfusion, including HIV and viral hepatitis. The donor must also answer questions about medical history and take a short physical examination to make sure the donation is not hazardous to his or her health. How often a donor can donate varies from days to months based on what component they donate and the laws of the country where the donation takes place. For example, in the United States, donors must wait eight weeks (56 days) between whole blood donations but only seven days between plateletpheresis donations and twice per seven-day period in plasmapheresis.

The amount of blood drawn and the methods vary. The collection can be done manually or with automated equipment that takes only specific components of the blood. Most of the components of blood used for transfusions have a short shelf life, and maintaining a constant supply is a persistent problem. This has led to some increased interest in autotransfusion, whereby a patient's blood is salvaged during surgery for continuous reinfusion—or alternatively, is "self-donated" prior to when it will be needed. (Generally, the notion of "donation" does not refer to giving to one's self, though in this context it has become somewhat acceptably idiomatic.)

Who can give blood

Most people can give blood. You can give blood if you:

  • are fit and healthy
  • weigh between 7 stone 12 lbs and 25 stone, or 50kg and 160kg
  • are aged between 17 and 66 (or 70 if you have given blood before)
  • are over 70 and have given blood in the last two years

How often can I give blood?

Men can give blood every 12 weeks and women can give blood every 16 weeks. Find out more about what happens on the day of your donation.

Check you are able to give blood

You can check some of the most common eligibility questions we receive from blood donors.

You can register here as a blood donor.

The common reasons donors should check if they can give blood are:

  • if you are receiving medical or hospital treatment
  • if you are taking medication
  • during and after pregnancy
  • if you feel ill
  • if you have cancer
  • after receiving blood, blood products or organs.

Women under 20 - check if you can give blood.