Severe congenital neutropenia is when an individual is born with severe neutropenia (defined as a neutrophil count of less than 500, usually less than 200 neutrophils per microliter). A specific form is called Costerman syndrome, which is a rare disorder that affects an estimated 1-2 people per million.
Symptoms of congenital neutropenia usually begin shortly after birth. Neutrophils are white blood cells that fight bacterial infections. An extremely low neutrophil count, which is characterized by this condition, increases the risk of bacterial infection. Fever is also a common symptom, but this is due to infection, not neutropenia.
Birth defects are generally not seen. Symptoms may include:
- recurrent fever
- sore throat (pharyngitis)
- Inflamed gums (gingivitis)
- Inflammation and pain in the mouth (stomatitis)
- Infections of the skin and other parts of the body
During one of these infections, your healthcare provider may get a complete blood count (CBC). In severe neutropenia (less than 500 cells/microliter), white blood cells are the only blood cell type affected. Red blood cells and platelets should be normal. Often, monocytes — another type of white blood cell — are also elevated. If more than one blood cell is affected, other diagnoses (eg, Shwachman Diamond syndrome) should be considered.
Once severe neutropenia is identified, your healthcare provider may consider referring you to a hematologist, a doctor who specializes in blood disorders. Initially, you may have 2 to 3 CBCs per week to rule out a cause of cyclic neutropenia (a more benign condition).
The next step is a bone marrow biopsy. The test involves removing a small piece of bone from your hip to assess the bone marrow, the area where white blood cells are made. In severe congenital neutropenia, cells are initially made normally, but at some point, they die before being released into the circulation.
If your bone marrow is consistent with severe congenital neutropenia, your healthcare provider may order genetic testing to identify your specific mutation. This is important because it will determine if or how you pass the condition on to your child.
- Granulocyte-colony stimulating factor (G-CSF or filgrastim): G-CSF is injected subcutaneously (subcutaneously) daily. This drug stimulates bone marrow production and neutrophil maturation. The goal is to keep neutrophil counts at consistently normal levels to prevent infection.
- Bone marrow transplant: A bone marrow transplant can be curative. This is usually used for people who have a poor response to G-CSF. If receiving a bone marrow transplant from a sibling, it is important to make sure that they do not have a less severe form of congenital neutropenia.
- Antibiotics: If you have severe congenital neutropenia and a fever, you should seek immediate medical attention. Fever may be the only symptom of a serious infection. Blood tests should be sent to determine possible causes of infection. During this time, you will receive intravenous (through a vein) antibiotics in case you get an infection.
Are there any long-term issues?
With better treatment, the life expectancy of people with severe congenital neutropenia is greatly improved. As people age, people with this disorder have an increased risk of developing myelodysplastic syndromes (MDS) and leukemias, mainly acute myeloid leukemia, compared to the general population. This risk is considered a secondary risk of G-CSF treatment, but now appears to be a complication of this condition.
Treatment with G-CSF may increase the size of the spleen and cause low platelet counts (thrombocytopenia, which may require splenectomy.