Neutropenia is a blood disorder characterized by a low neutrophil granulocyte (commonly called neutrophils) count. As they are the most common type of white blood cell in the human body, neutrophils are necessary for the operation of the immune system. They are normally found in the blood stream, but they are the predominate type of cell which localizes at the site of an infection (for example, in pus). Neutropenia can lead to increased susceptibility to infections. A broader condition of white blood cell deficiency is Leukopenia, and at times the terms are used interchangeably. However, Leukopenia means that more types of cells than just the neutrophils are below average levels, and Neutropenia is only one of the conditions of that make up Leukopenia.
The causes of Neutropenia are either rooted in cell destruction and/or the inhibition of blood production due to issues with bone marrow. Some of the causes of Neutropenia include:
- Congenital defects
- Exposure to excessive levels of radiation
- Aplastic anemia
- Autoimmune disorders
Chemotherapy causes neutropenia by the destruction of tissues, including bone marrow, and the alteration of chemicals and DNA instructions induced by chemotherapy medications. It is a side effect which is common in patients undergoing chemotherapy, but the severity of the Neutropenia may be reduced in correlation to the dosage of the medication or by taking breaks to rebuild cells.
Diagnosis of neutropenia is done by a full blood count. If low neutrophil counts are discovered, more tests can be done to diagnose whether or not the low count is Neutropenia or would be more aptly described in another way. A full blood count is a simple procedure done by taking blood samples from the patient, and then the samples are sent to a lab for processing.
If the case seems to be serious or the blood count is inconclusive, a bone marrow biopsy may be necessary. In a bone marrow biopsy, the doctor takes a bone marrow sample from, usually, the hip of the patient. The procedure involves a doctor placing a needle into the hip of a patient until it hits the outer layer of the bone called the bony cortex. Once the needle is placed against the bony cortex, the doctor turns the needle like a screw to drive it through to the bone marrow. The bone marrow is then extracted by pulling it into the needle. The blood test and bone marrow biopsy may be repeated multiple times if needed.
A possible treatment for neutropenia is the use of the Granulocyte Colony-Stimulating Factor (GCSF). GCSF is a glycoprotein which stimulates bone marrow to produce neutrophils. While GCSF therapy will counteract the effects of Neutropenia, it is not a long-term cure. A second treatment is a bone marrow transplant, but due to the risks involved in the operation, it is reserved as a second line treatment in the case of a GCSF treatment failure. The third line of treatment, if the other two fail, is corticosteroids. Steroid treatments have not been shown to improve neutropenia in a majority of patients, but the treatment has caused improvements in a select few who have shown no response to GCSF treatment or bone marrow transplants.
In the case of an emergency, a white blood cell transfusion may be used to preserve the life of a patient, but its use is rare as it is not a viable option for long-term treatment due to the limited supply.