An absolute neutrophil count (ANC) is a blood test that measures the amount of a specificwhite blood cell—called aneutrophil—in a sample of blood. If absolute neutrophils are low, you are at risk for an infection, while a high neutrophil count may be a sign of infection or inflammatory disease. Neutrophil levels can also be used to check for certain cancers like leukemia and lymphoma.
This article explains what an absolute neutrophil count test is, how the results are interpreted, and what it means if your ANC is high or low.
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What Are Neutrophils?
White blood cells (WBCs) are an important part of your immune system and will increase whenever there is a disease or infection. Neutrophils, produced by your bone marrow, are among the "first responders" to any disease or infection.
Neutrophils make up roughly 50% of your total WBCs.
Absolute Neutrophil Count Test (ANC)
The ANC is part of a common blood test called a complete blood count (CBC) that evaluates the composition, proportion, characteristics, types, and numbers of red blood cells, white blood cells, and platelets in a sample of blood. It is used to assess a potential infection or illness.
Since neutrophils account for half of the WBCs, rather than isolating and counting each neutrophil individually, the ANC is calculated simply by multiplying your total WBCs by 50%. A total WBC count of 8,000 means an ANC of 4,000, reported as cells per microliter of blood (cells/mcL).
This number is then compared against a reference range of values. The reference range of values for an ANC test can vary based on a person's age and other factors. Most labs in the United States consider a normal ANCto be between 2,500 and 6,000 cells/mcL.
Anything below or above the reference range of values is flagged in the lab report as a possible sign of a medical concern.
Low Neutrophils and Black People
A low neutrophil count does not always indicate illness in people of African descent. This has been called benign ethnic neutropenia, but it's really based on differences in the Duffy antigen in blood. In the U.S., about 4.5% of Black people have neutropenia-level counts compared with 0.8% of White people. Researchers are developing an appropriate reference range to reflect the difference.
Confused About Your Health? The Answer May Be in Your Blood
Low Absolute Neutrophil Count
A low absolute neutrophil count is referred to as neutropenia. This occurs when the ANC is less than 2,500 cells/mcL. At levels below 1,000, you are at an increased risk of infection.
Neutropenia is mainly caused by the suppression of your bone marrow. There are diseases, infections, and medications that can cause this. The causes fall into categories that include:
- Congenital, such as benign ethnic neutropenia (now called Duffy null-specific)
- Infection-associated, including potentially fatal systemic sepsis
- Drug-induced neutropenia, including agranulocytosis(often linked to clozapine use)
- Autoimmune conditions (some occur in children, including Evans Syndrome)
- Cancers, including leukemia and lymphoma
- Diet and nutrition, as with folate deficiency or general malnutrition
The test doesn't explain why the neutrophil count is low. A healthcare provider will want to know why the bone marrow is unable to produce enough neutrophils to defend the body against disease or infection.
Chemotherapy and Neutropenia
Chemotherapy-induced neutropenia (CIN) occurs when cancer treatments cause low neutrophil counts. This complication can lead to fever, sepsis and other life-threatening complications. In some cases, treatment is affected because chemotherapy drugs need to be discontinued or changed to lower doses. Risk factors include age and co-occurring health conditions, like diabetes.
Why Blood Typing Is Done
Common Symptoms
You won't necessarily have symptoms of neutropenia until you develop a disease or infection as a result of a low neutrophil count. Depending on the underlying condition, this may involve:
- Fever
- Chills
- Cough
- Shortness of breath
- Diarrhea
- Abdominal pain
- Fatigue
Mouth sores also can occur with low neutrophil counts. Some people may develop a rash or swelling at the joints, depending on the cause.
Identifying Mouth Sores From Pictures
How to Raise Your Neutrophil Count
If you have a low neutrophil count, the first course of treatment is to resolve the underlying cause. These treatments may include:
- Stopping or adjusting medications like chemotherapy drugs that cause neutropenia
- Trying a drug like Neupogen (filgrastim) or Neurapeg (pegteograstim) that stimulates white blood cell growth in people with cancer
- Blood transfusions to boost WBC counts
- Leukapheresis, a blood filtering treatment that may be needed in treating leukemia
Since some causes of neutropenia may be drug-induced or diet-related, talk to your healthcare provider about any needed lifestyle or medication changes to help raise your neutraphil count.
High Absolute Neutrophil Count
A high absolute neutrophil count is called neutrophilia. This occurs when the ANC is over 6,000 cells/mcL. An ANC over 11,000 is a strong indication that your body is fighting a disease or infection.
Neutrophilia means that some sort of inflammatory process is going on in your body and your immune system has launched a defense by producing more neutrophils.
Common causes of neutrophilia include:
- Infections like the Epstein-Barr virus or pneumococcal infections
- Inflammatory conditions, including chronic myeloid leukemia (CML) or essential thrombocythemia, a rare type of blood cancer
Less common causes include:
- Solid tumor cancers (these typically occur in organs, like the pancreas or liver)
- Anemia, even though it's typically associated with neutropenia
- Cryoglobulinemia, a rare blockage of small blood vessels often seen in hepatitis B and C
High neutrophil counts also can occur with common conditions like allergies, arthritis, or a tissue wound like burns. Some medications, including corticosteroids, also can cause neutrophils to rise.
Common Symptoms
As with neutropenia, it's the diseases or conditions that cause neutrophilia that can manifest with symptoms. They typically include signs of infection, such as:
- Fever
- Cough
- Abdominal pain
- Fatigue
- Weight loss
How to Lower Your Neutrophil Count
Treatment for neutrophilia is targeted toward the underlying cause or condition. Antibiotics or antifungals can be used to treat infection, or different therapies or drug dosages can be used to treat cancer. Allergy treatments or wound care also can treat a temporary elevation.
Summary
Neutrophils are a type of white blood cell that help your body fight infection. An ANC test measures the number of neutrophils in your blood.In most healthy people, more than 50% of white blood cells are neutrophils.
Your neutrophils might be low or high for various reasons, including an infection, certain inflammatory diseases, leukemia, lymphoma, and certain medications. Your healthcare provider will focus on the underlying cause if treatment is needed.
