There are three groups of cells that circulate around in the blood stream.

These are:

1. red blood cells (often referred to as haemoglobin),
2. platelets (small cells that help in the blood clotting system) and;
3. white blood cells.

Neutrophils are a particular type of white cell. Neutrophils are a very important part of the immune system and play an important role in protecting the body against bacterial infections.

The number of neutrophils that circulate in the blood stream varies a bit according to age however the usual range of normal neutrophil numbers is 1.5 – 8.0 X 10^9/l (1.5 million – 8 million neutrophils per litre) of blood or 1500 – 8000 neutrophils per millilitre (ml) of blood.

Bacterial “Fighters”
Neutrophils are particularly important in fighting bacterial infections. Bacteria is responsible for causing many different types of infections (e.g. some common ear infections, skin and wound infections) but sometimes these infections can be serious (e.g. blood infections).

Bacterial infections are treated with antibiotics unlike viral infections e.g. flu like illnesses, and the common cold which do not require treatment with antibiotics. Because your body has low neutrophils, you may be more susceptible to bacterial infections because you have fewer neutrophils to ‘fight’ the infection.

There are a number of reasons why people have low neutrophils. Some people are born with low neutrophils, other people develop conditions that cause low neutrophils – these include immune problems, exposure to some drugs and some viral infections (such as flu like illnesses). There are a number of other rare causes of neutropenia.

The types of blood tests required to determine the cause of the neutropenia will depend on how long you have had the low neutrophils. Sometimes only one or two blood tests are required; other times many blood tests and even a bone marrow test may be required.

The major problem or risk factor with neutropenia is the risk of developing a (serious) bacterial infection. Sometimes it is difficult to find out if you have a bacterial infection (which needs treatment with antibiotics) or a viral infection (which does not need treatment with antibiotics).

Most infections that people pass on to each other are viral infections (e.g. the common cold). Most serious bacterial infections are not easily transferred from one person to the next. Generally you do not need to isolate yourself from other people.

This will depend on the cause of the neutropenia. Although some causes of neutropenia will not get better, most causes of neutropenia get better over a couple of months or sometimes years. Other causes of neutropenia take many years to get better.