Medically reviewed by Corey S. Cutler, MD, MPH
Neutropenia is a condition associated with a low white blood cell count. These types of white blood cells, called neutrophils, are made in the bone marrow and fight off infections. If there is a decrease in neutrophil production, an accelerated usage of neutrophils, or an increased destruction of neutrophils, the risk of infection increases, particularly those caused by bacteria or fungi.
Adults that have less than 1,500 neutrophils per microliter of blood are considered neutropenic, but some people can have lower-than-average neutrophil counts but not have an increased risk of infection. Neutrophil counts less than 1,000 per microliter – and in severe cases, less than 500 per liter – are always considered to be neutropenia and are at the highest risk of infection.
What causes neutropenia?
Cancer chemotherapy is the most common cause of neutropenia. Other cancer treatments, including radiation therapy, stem cell or bone marrow transplants, or steroids (which usually actually raise the neutrophil count, but still increase the risk of infection), can also lower neutrophil count. Sometimes, while destroying cancer cells, these treatments can also affect normal, healthy cells like neutrophils, resulting in immunosuppression: compromised immune system functioning.
Additionally, neutropenia can result from specific diseases, such as leukemia or bone marrow disorders, among others, or from certain infections, such as hepatitis A, B, and C, or Lyme disease.
How do doctors diagnose neutropenia?
Doctors use a blood sample to diagnose neutropenia. They look to the absolute neutrophil count (ANC), the number of neutrophils in a certain amount of blood, to monitor the patient’s immune system before, during, and after treatment.
What are symptoms of neutropenia?
Neutropenia alone has no specific symptoms, but it is typically diagnosed in the context of a fever or an infection. Often, a persistent infection is also what leads doctors to test blood cells counts to identify blood cell cancers like leukemia. When a patient is neutropenic, severe infections can develop rapidly and become overwhelming in the space of minutes to hours. Fortunately, because doctors expect potential changes in immune responses during various cancer treatments, they pay close attention to fluctuations in blood counts to prevent such occurrences.
How is neutropenia treated?
The treatment of neutropenia itself depends on its cause and severity. Drugs that may cause neutropenia can be stopped whenever possible and exposures to infections or suspected toxins can be avoided. If an underlying disease has caused the neutropenia, treatment of the disease will then impact treating the neutropenia.
Special medications can be used to help bone marrow regenerate new neutrophils, according to Corey Cutler, MD, MPH, director of the Stem Cell Survivorship Clinic at Dana-Farber. These medications, called Growth Factors, are hormones that are naturally produced by the body. In certain situations, these medications can be used to help the body regenerate neutrophils and other white blood cells.
If you are diagnosed with neutropenia, food safety is another important way to limit exposure to potential food-borne pathogens while still providing adequate nutrition. Bacteria tend to grow in foods that are very moist, have lots of freely accessible carbohydrates, and are room temperature.