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Together is a new resource for anyone affected by pediatric cancer - patients and their parents, family members, and friends.
Learn MoreA complete blood count test (CBC) measures the number and types of cells in the blood. A CBC test can also measure some proteins made by the blood cells.
Blood is a body fluid that has cells in a liquid called plasma, made of water and proteins. Children with infections, cancers, or blood disorders have changes in the number and kind of cells and proteins in their blood. Therapies and medications can also change their blood.
Blood has red blood cells, white blood cells, and platelets that are in a fluid called plasma. The CBC measures how many of each kind are in the blood.
Blood cells have important jobs. The body has 3 main types:
A differential test gives even more information about the white blood cells that fight infection and disease.
Health care providers use the CBC with differential tests to:
Follow your health care provider’s instructions before the test. Tell them if your child is taking any:
These things may change the test results. If your child is only getting a complete blood count test (CBC), they might be able to eat and drink as normal. But if your doctor orders other blood tests, they might not be able to eat or drink.
For children with cancer, regular complete blood count tests help the care team monitor the patient’s health and ability to fight off infections.
A care team member inserts a needle into your child’s vein to get a blood sample and collects it in vials or tubes. They can also get blood from your child’s central venous access device such as a:
If your child does not have a device, the provider might start a peripheral IV to get blood samples.
The laboratory staff will study your child’s blood and report the results to your doctor.
CBC tests measure:
The number of cells, their size, and types in healthy person usually falls within a range of numbers (reference range or standard range). Your doctor compares your child’s results to normal reference ranges. Normal ranges can vary widely and depend on your child’s age. You should review these results with your health care provider who can explain what is normal for your child.
A complete blood count with a differential looks more closely at the types of white blood cells in the blood to study your child’s disease.
Neutrophils are the most common type of white blood cell. They travel to the site of an infection and release substances called enzymes to fight off invading viruses or bacteria. Your provider may order a test called the absolute neutrophil count (ANC) test to track your child’s neutrophil levels and study how their body responds to infection and abnormalities.
There are two main types of lymphocytes: B cells and T cells. B cells fight off invading viruses, bacteria, and toxins. B cells are also play a role in the response to cancer. T cells target and destroy cancer cells or cells infected with viruses. There are also some types of cancer that have abnormal B cells or T cells.
These cells remove foreign material such as germs, remove dead cells, and boost the body's immune response by producing substances that fight disease.
These cells fight infection, inflammation, and allergic reactions such asthma attacks. They also defend the body against parasites, bacteria and fungus.
Basophils. These cells affect allergic reactions, protection against parasites, and the immune response to some cancers.
Low numbers or abnormalities of certain types of blood cells can lead to health conditions that require treatment such as anemia, blood clotting disorders, bleeding disorders, and leukopenia (low numbers of white blood cells, and blood cancers.
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Reviewed: March 2022