What is neutropenia? What causes neutropenia?

Neutropenia is a blood condition, a granulocyte disorder, that characterized by a deficiency of neutrophils, a type of white blood cell that defends the body against bacterial and fungal infections.

Granulocytes are a category of white blood cells. They are made in bone marrow. They contain microscopic granules with proteins (enzymes) that digest invading bacteria, viruses, fungi and parasites and play a key role in our immune system response.

There are three types of granulocytes:

• Neutrophils


• Eosinophils


• Basophils

Neutropenia refers to a deficiency of neutrophils only, while agranulocytosis is when the bone marrow fails to make enough granulocytes in general (the three types). The two terms are often mistakenly used interchangeably.

Neutrophils surround invading bacteria or fungi and ingest them. Between 50% and 70% of our circulating white blood cells consist of neutrophils.

Patients with neutropenia are more likely to suffer complications from bacterial infections, which can sometimes develop into life-threatening neutropenic sepsis.

Types of neutropenia

There are several types of neutropenia. Some people are born with the disorder, others get it after taking certain prescription drugs, some after becoming ill, and in others patients the cause it not known.

Below are some basic types of neutropenia: (Source: Neutropenia Support, Australia)

• Congenital neutropenia - the patient is born with it. This type is very rare. The most severe form is known as Kostmann's syndrome.


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• Cyclic neutropenia - also very rare. Patients have low neutrophil levels every three weeks - the low level persists for 3 to 6 days each time. Consequently, they are more susceptible to becoming ill from infections in cycles of between three to four weeks, hence the name.


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• Idiopathic neutropenia - usually occurs as a result of being ill. Doctors often use this term if the patient is getting very sick all the time, but nobody is able to associate the symptoms to other diseases.


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• Autoimmune neutropenia - more commonly found in babies and young children. The body's immune system destroys the neutrophil cells. Fortunately, in many cases the child's symptoms improve with time.


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• Drug-induced neutropenia - occurs when the patient is taking a medication that may lower the white blood cell count.