Neutropenia - An UnderstandingDennis A. Gastineau, MD
Director, Human Cell Therapy Laboratory
Divisions of Transfusion Medicine and Hematology
written for Patient Advocate Foundation
Neutropenia is a deficiency of white blood cells, the dominant bacterial infection-fighting defense of the body. More particularly, neutropenia refers to a deficiency of the neutrophil class of white blood cells, also known as "polys" or "segs." There is a wide variation of normal white blood cell counts, and a decrease of white blood cells becomes important when an increase of infections occurs in association with the decreased count.
Neutropenia may be congenital (a condition from birth), a variation of normal, acquired due to bone marrow or autoimmune disease, or it may occur as a result of drugs. Drugs may be expected to cause neutropenia (such as chemotherapy drugs for cancer), or unexpectedly cause neutropenia (called an idiosyncratic reaction).
How do I know I have neutropenia?
Many times neutropenia may occur without any symptoms at all. In this situation the mere presence of a low count may not be important. However, if you experience any of the following, the decreased white count may indeed be important:
- Recurrent skin infections, particularly around the nose and mouth
- Recurrent pneumonia
- Recurrent sinus infections
These events occur because of a lack of sufficient white blood cells or neutrophils to kill the bacteria causing these types of infections. Bacteria are killed by several mechanisms involving neutrophils, but there must be enough cells before these mechanisms can accomplish the killing.
Where to neutrophils come from?
Neutrophils, along with red cells and platelets are made in the bone marrow, located in the center of many of the larger bones of your body. The bone marrow needs iron, vitamins and other building blocks from food to make a proper amount of white blood cells. Neutrophils circulate for a very short time, often just a few hours, so the bone marrow must continuously make neutrophils in order to maintain a normal number of cells.
What causes neutropenia?
Neutropenia is having too few white blood cells, neutrophils, and may occur from too few cells being formed or can occur from cells being destroyed more quickly than usual. Drugs or nutritional deficiencies may reduce the rate of production of neutrophils. Abnormal bone marrow conditions such as myelodysplastic syndromes, leukemia, or aplastic anemia may cause a decrease in production of neutrophils.
Destruction of neutrophils at a faster than normal rate may also result in a decreased neutrophil count. There are a number of diseases that can cause increased destruction of white blood cells including autoimmune disorders such as rheumatoid arthritis or lupus. Sometimes an enlargement of the spleen can cause white cells to be destroyed more quickly. Diseases that enlarge the spleen include chronic liver disease and cancers of the lymph system.
Drugs used in the treatment of many cancers very commonly cause neutropenia as an expected side effect of the treatment. Usually your doctor will discuss this side effect if you are receiving treatment for cancer, and precautions may be taken against getting infections during this time. The same drug effects that kill cancer cells often cause the bone marrow to transiently stop producing white blood cells. Since the decrease in white cells is temporary, the risk of infection is also temporary but can be large.
Radiation, even of a small portion of the body, can cause neutropenia, and may last for several days after the completion of the treatment.
There are a number of inherited diseases that cause abnormal function of neutrophils that can imitate the problems of neutropenia even if the white blood cell count is normal.
Am I likely to have neutropenia?
If you are not undergoing treatment for cancer or certain autoimmune disorders, and if you do not have any chronic conditions and have not taken any new medications recently, neutropenia is actually very uncommon. But if you have been having frequent infections requiring antibiotics which just don't seem to go away or require treatment more than three or four times in a year, an assessment of your white cells may be wise.
Should I ask if I have neutropenia?
If you have had recurrent infections needing antibiotics it is reasonable to ask. Unlike anemia, neutropenia may not be detected at the time of blood donation because white blood cell counts are not performed during the donation process.
How will my doctor know if I have neutropenia?
Neutropenia can be diagnosed with a blood test, a CBC or "complete blood count." Some older office CBC machines may not separate the types of white blood cells, so either a blood smear or a referral to another laboratory may be necessary.
What can be done for neutropenia?
Treating the condition causing the neutropenia usually treats Neutropenia. Sometimes the best treatment is the prevention of the complications of neutropenia, the infections, by the administration of regular courses of antibiotics. A common schedule is the first 7 days of each month with a variety of antibiotics. Sometimes treatment of the underlying condition will make the neutropenia worse, and during the time of very low blood counts your doctor may choose to give a growth factor to stimulate the production of white blood cell. G-CSF, or granulocyte colony stimulating factor, may stimulate the production of more mature neutrophils. It has more than one form, one of which needs only a once per week injection. The cost of G-CSF is high if it is given over an extended period of time.
Steroids such as prednisone may stimulate a temporary rise in neutrophils, but is generally avoided in chronic neutropenia since steroids may increase the risk of many kinds of infections.
Guideline for cancer patients with neutropenia: Click Here