Granulocytes are a type of white blood cell that help fight infection. 'Agranulocytosis ' and 'neutropenia' are terms often used to describe a deficiency of these cells.
However, the two terms shouldn't be used interchangeably, as they describe slightly different conditions.
- agranulocytosis is the term used when the bone marrow (soft tissue inside bone) fails to make enough granulocytes
- neutropenia is the term used when the bone marrow fails to make enough of a specific group of granulocytes called neutrophils
Although these conditions are slightly different, they tend to share many similar causes and symptoms, and are often treated in a similar way.
What causes low white blood cell count ?
Agranulocytosis and neutropenia usually occur later in life, as the result of another condition or treatment (acquired), but can sometimes be present from birth (congenital).
Depending on the cause, your white blood cell count may recover over time. However, in some cases, the problem can be persistent.
Acquired agranulocytosis and neutropenia
Common causes of acquired agranulocytosis or neutropenia include:
- chemotherapy or a bone marrow transplant (or preparation for a bone marrow transplant)
- certain medications – including some anti-psychotics and some medications for an overactive thyroid gland (hyperthyroidism)
- an autoimmune disorder (where the body's immune system mistakenly attacks its own tissues) – such as lupus and rheumatoid arthritis
- a bone marrow disease – such as myelodysplasia (where blood cells do not develop properly) or leukaemia
- certain infections – including HIV and hepatitis
Congenital agranulocytosis and neutropenia
Congenital agranulocytosis or neutropenia can be caused by several rare genetic faults (altered genes) that may be passed on to a child by one or both of his or her parents.
Individuals of Afro-Caribbean descent often have a naturally slightly lower neutrophil count than those of other ethnic origins, but this is entirely normal and does not lead to any health problems.
Signs and symptoms of low white blood cell count
Most people with agranulocytosis or neutropenia will not have any obvious symptoms.
However, these conditions may mean you are more vulnerable to picking up infections because you don't have enough white blood cells to fight germs effectively.
Symptoms associated with an infection can include:
- a high temperature (fever)
- chills and shivering
- facial flushing
- a sore throat or mouth
- mouth ulcers
- swollen glands
- a lack of energy
- flu -like symptoms
In some people, infections can spread quickly through the body and can lead to a life-threatening condition called sepsis . In addition to some of the above symptoms, sepsis can also cause a fast heartbeat and fast breathing.
Seeking medical advice
Most people at risk of agranulocytosis or neutropenia should already be aware of signs to look out for, and will have been told what to do if they experience them.
For example, if you have been having chemotherapy, your cancer care team may have given you a telephone number you can call if you experience any problems, such as a high temperature.
If you know you are at risk of these white blood cell deficiencies and you start to feel unwell, it's important to contact your doctor or care team immediately.
Sepsis is a medical emergency and should be assessed by a doctor in hospital as soon as possible so appropriate treatment can be started quickly.
Diagnosing and managing agranulocytosis and neutropenia
If your doctor suspects you have agranulocytosis or neutropenia, they will carry out a blood test to check the level of white blood cells in your blood.
If one of these conditions is diagnosed, the treatment and advice offered to you will depend on the cause and severity of your condition.
Reducing your infection risk
You will often be given some advice about ways you can reduce your risk of infection while your white blood cell count is low. This may include:
- avoiding undercooked and some raw foods that could lead to food poisoning
- avoiding close contact with people you know have an infection
- making sure you store and prepare food properly
- maintaining good personal hygiene, such as washing your hands with soap and warm water regularly
Read more about food safety and preventing germs from spreading.
If you develop an infection, you will usually need to be treated with antibiotics because your body will not be able to fight the infection itself.
Depending on the severity of the infection, you may be given antibiotic tablets to take at home, or you may need to have antibiotics given directly into a vein (intravenously) while in hospital.
In some cases, you may be given a course of low-dose antibiotics to take to stop infections developing in the first place.
Some people may need injections of a medication called G-CSF (granulocyte-colony stimulating factor), which can stimulate the bone marrow to produce more white blood cells.
In very rare cases, you may need to go to hospital to have a type of blood transfusion where you are just given granulocyte cells. Granulocytes for transfusion are ideally taken from a donor who is a friend or relative.
The donor is given corticosteroid medication plus G-CSF, which helps them to produce more granulocytes and increases the number of these in their blood. The donor's blood is then removed and the white cells are separated out for transfusion.
The transfusion is usually given through a tiny plastic tube called a cannula, which is inserted into a vein in your arm.
Bone marrow transplant
In particularly severe cases, you may need a bone marrow transplant (stem cell transplant) to replace your damaged bone marrow with healthy bone marrow stem cells taken from a donor.