Neutropenia is a blood condition. It occurs when neutrophil levels are low. Neutrophils are a type of white blood cell that protects your body from infections.
Without enough neutrophils, your body can’t fight against bacteria. Having neutropenia increases your risk of many types of infection.
There are four types of neutropenia: congenital, cyclic, autoimmune, and idiopathic.
Congenital neutropenia and cyclic neutropenia are present at birth. Autoimmune neutropenia and idiopathic neutropenia develop later in life.
Severe congenital neutropenia is also called Kostmann syndrome. It causes very low neutrophil levels. In some cases, neutrophils are absent. This puts infants and young children at risk for serious infections.
Cyclic neutropenia causes neutrophil counts to vary in a 21-day cycle. Neutrophil counts fall from normal to low. A period of neutropenia may last a few days. Normal levels follow for the rest of the cycle. The cycle then resets and begins again.
In autoimmune neutropenia, your body makes antibodies that fight your own neutrophils. These antibodies kill the neutrophils, and this causes neutropenia.
Idiopathic neutropenia can affect anyone. The cause is unknown.
Neutropenia can be triggered by chemotherapy, radiation therapy, and the use of certain drugs. Other causes are: