Fanconi Anaemia Australia

Acknowledgements
Fanconi Anaemia Australia Ltd gratefully acknowledges The Leukaemia Foundation of Australia for granting us permission to use some of the material in their booklets and information sheets to provide the following information (Oct 2009)

Bone Marrow
Bone marrow is the spongy tissue that fills the cavities inside your bones. Most of your blood cells are made in your bone marrow. The process by which blood cells are made is called haemopoiesis. In infants, haemopoiesis takes place at the centre of all bones. In adults, it is limited to the hips, ribs, spine, skull and breastbone (sternum). Some of you may have had a bone marrow biopsy taken from the bone at the back of your hip (the iliac crest) or the breastbone.
You might like to think of the bone marrow as the blood cell factory. The main workers at the factory are the blood stem cells. They are relatively small in number but are able, when stimulated, not only to divide to replicate themselves, but to grow and divide into slightly more mature stem cells called myeloid stem cells and lymphoid stem cells. These cells multiply and mature further to produce all the circulating blood cells. There are three main types of blood cells: red cells, white cells and platelets.

Stem cell diagram

Myeloid (‘my-loid’) stem cells develop into red cells, white cells (neutrophils, eosinophils, basophils and monocytes) and platelets.
Lymphoid (‘’lim-foid’) stem cells develop into two other types of white cells called T-lymphocytes and B-lymphocytes.

Growth factors and cytokines

All normal blood cells have a limited survival in circulation and need to be replaced on a continual basis. This means that the bone marrow remains a very active tissue throughout your life. Natural chemicals in your blood called growth factors or cytokines control the process of blood cell formation. Different growth factors stimulate the blood stem cells in the bone marrow to produce different types of blood cells.
These days some growth factors can be made in the laboratory (synthesised) and are available for use in people with blood disorders. For example, granulocyte-colony stimulating factor (G-CSF) stimulates the production of white cells called neutrophils while erythropoeitin (EPO) stimulates the production of red cells. Unfortunately, drugs to stimulate platelet production have been less successful, but research is continuing in this area.

Blood

Red cells and haemoglobin

Red cells contain haemoglobin (Hb), which gives the blood its red colour and transports oxygen from the lungs to all parts of the body. Haemoglobin also carries carbon dioxide to the lungs where it can be breathed out.
The normal haemoglobin range for a man is between
130 and 170 (130 – 170 g/L)
The normal haemoglobin range for a woman is between
120 and 160 (120 – 160 g/L)

Red cells are by far the most numerous blood cell and the proportion of the blood that is occupied by blood cells is called the haematocrit. A low haematocrit suggests that the number of red cells in the blood is lower than normal.
The normal range of the haematocrit in a man is between 40% and 52%
The normal range of the haematocrit in a woman is between 36% and 46%

Anaemia

Anaemia is a condition caused by a reduction in the number of red cells, which in turn results in a low haemoglobin. Measuring either the haematocrit or the haemoglobin will provide information regarding the degree of anaemia.
If you are anaemic you will feel run down and weak. You may be pale and short of breath or you may tire easily because your body is not getting enough oxygen. In this situation a red cell transfusion may be given to restore the red cell numbers and therefore the haemoglobin to more normal levels.

White cells

White cells fight infection. There are different types of white cells that fight infection together and in different ways.

Neutrophils kill bacteria and fungi
Eosinophils kill parasites
Basophils work with neutrophils to fight infection
Monocytes work with neutrophils and lymphocytes to fight infection; they also help with
antibody production and act as scavengers to remove dead tissue
T-lymphocytes kill viruses, parasites and cancer cells; produce cytokines
B-lymphocytes make antibodies which target microorganisms

When your white cell count drops below normal you are at risk of infection.
The normal adult white cell count varies between
3.7 and 11 (3.7 – 11 x 109/L)

Neutropenia

Neutropenia is the term given to describe a lower than normal neutrophil count. If you have a neutrophil count of less than 1 (1 x 109/L) you are considered to be seriously neutropenic and at risk of developing frequent and sometimes severe infections.
The normal adult neutrophil count varies between
2.0 and 7.5 (2.0 – 7.5 x 109/L)

Platelets

Platelets are disc-shaped cellular fragments that circulate in the blood and play an important role in clot formation. They help to prevent bleeding. If a blood vessel is damaged (e.g. by a cut) the platelets gather at the site of injury, stick together and form a plug to help stop the bleeding.
The normal adult platelet count varies between
150 and 400 (150 – 400 x 109/L)

Thrombocytopenia

Thrombocytopenia is the term used to describe a reduction in the platelet count to below normal. If your platelet count drops below 20 (20 x 109/L) you are at risk of bleeding and tend to bruise easily. Platelet transfusions are sometimes given to bring the platelet count back to a safe level.
The normal blood counts provided here may differ slightly from the ones used at your treatment center. You can ask for a copy of your blood results, which should include the normal values for each blood type.

Children

In children, some normal blood cell counts vary with age. If your child is being treated for leukaemia you can ask your doctor or nurse for a copy of their blood results, which should include the normal values for each blood type for a male or female child of the same age.

In children, some normal blood cell counts vary with age (see table below).
Normal range of blood values for children