Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Mary D. Nettleman, MD, MS, MACP
Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.
In this Article
- Neutropenia facts
- What is neutropenia?
- How is neutropenia defined?
- What are the clinical consequences of neutropenia?
- What causes neutropenia?
- How is neutropenia diagnosed?
- How is neutropenia treated?
- Find a local Hematologist in your town
How is neutropenia defined?
The white blood cell count (WBC) is the number of white blood cells in a volume of blood. The normal range for the WBC varies slightly among laboratories but is generally between 4,300 and 10,800 cells per microliter or cubic millimeter (cmm). The WBC can also be referred to as the leukocyte count and can be expressed in international units as 4.3 x 109to 10.8 x 109 cells per liter. The percentage of the different types of white blood cells in the WBC is called the WBC differential.
The absolute neutrophil count (ANC) is determined by the product of the white blood cell count (WBC) and the fraction of neutrophils among the white blood cells as determined by the WBC differential analysis. For example, if the WBC is 10,000 per microliter and 70% are neutrophils, the ANC would be 7,000 per microliter.
An ANC of less than 1500 per microliter (1500/microL) is the generally accepted definition of neutropenia. Neutropenia is sometimes further classified as:
- mild if the ANC ranges from 1000-1500/microL,
- moderate with an ANC of 500-1000/microL, and
- severe if the ANC is below 500/microL.
Some medical terms may be used synonymously with neutropenia, even though their precise definitions are different.
- Leukopenia refers to a reduced number of white blood cells in general, while granulocytopenia refers to a decreased number of all the granulocyte-type blood cells (neutrophils, eosinophils, and basophils).
- Since neutrophils normally far outnumber the other types of granulocytes, this term is sometimes used to refer to neutropenia.
- Finally, agranulocytosis literally refers to a complete absence of all granulocytes, but this term is sometimes used to refer to severe neutropenia.
What are the clinical consequences of neutropenia?
Neutropenia results in an increased susceptibility to bacterial infections. The degree of risk depends upon the cause and severity of the neutropenia, the underlying medical condition of the patient, and the presence or absence of bone marrow reserves for the production of neutrophils.
The most common types of infection seen in neutropenic patients (patients with low white blood cell counts) are caused by bacteria normally found on the skin (such as Staphylococcus aureus) or from the gastrointestinal and urinary tract. Fungal infections are also more frequent in patients with neutropenia. The infections may be limited to certain areas of the body (commonly the oral cavity, genital area, and skin) or may spread via the bloodstream to the lungs and other organs in severe, prolonged neutropenia.
Next: What causes neutropenia?
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