Principles of treatment
- You should be treated by a specialist doctor or team, experienced in treating patients with SCD. If the specialist is a long way from your home then some of your treatment may be with a more local hospital or doctor – but the local doctors should get advice from your specialist.
- Because symptoms of SCD can start suddenly, you should be able to see a doctor and get hospital treatment urgently, as and when needed.
- You can be shown how to recognise symptoms (in yourself or your child), so that treatment can be started quickly.
- Treatment should be tailored to your individual needs.
- It is important to take preventative treatments against infection, and to attend your check-ups.
What causes sickle cell disease (SCD)?
The cause is inherited (genetic). It is a change in the genes which tell the body how to make an important protein called haemoglobin. To get SCD, you need to have two altered haemoglobin genes, one from each parent. If you only have one of these genes, you will have sickle cell trait, which is very much milder.
The most common type of SCD is where you have two sickle cell genes (sickle cell anaemia). The medical shorthand for this is haemoglobin SS or HbSS. Other types of SCD involve one sickle cell gene plus another abnormal haemoglobin gene of a different type. These include: haemoglobin SC; haemoglobin S/beta thalassaemia; haemoglobin S/Lepore; haemoglobin SO Arab.
The symptoms, diagnosis and treatment are similar for all the sickle cell conditions.
How do the sickle cell genes cause SCD?
Sickle cell genes affect the production of an important chemical called haemoglobin. Haemoglobin is located in red blood cells, which are part of the blood. Haemoglobin carries oxygen and gives blood its red colour.
The sickle cell genes make the body produce abnormal haemoglobin called HbS. (Normal haemoglobin is called HbA.) HbS behaves differently from HbA. Under certain conditions, HbS makes the red blood cells change shape – instead of the normal doughnut shape, they become sickle-shaped, like a crescent moon. This is called sickling. Conditions which trigger sickling are cold, infection, lack of fluid in the body (dehydration), low oxygen, and acid (acid is produced in hard physical exercise).
What happens to the sickle cells?
The sickle cells containing mostly HbS are harder and less flexible than normal red blood cells. So, they can get stuck in small blood vessels and block them. This can happen quite suddenly, causing various symptoms which are known as a sickle cell crisis (explained below). Repeated blockages can also lead to complications occurring.
The sickle cells are destroyed more easily than normal red blood cells. This means that people with SCD tend to be short of red blood cells and have a moderate and persistent anaemia. A moderate anaemia is not usually a problem because the HbS (the different haemoglobin) carries oxygen well, and the body can compensate. However, you may get bouts of severe anaemia for various reasons. For example, if too much blood goes to the spleen, if too many red blood cells break down at the same time, or due to certain infections which stop blood cells being made. A severe anaemia can make you very ill.
Sickle cell anemia is an inherited form of anemia — a condition in which there aren’t enough healthy red blood cells to carry adequate oxygen throughout your body.
Normally, your red blood cells are flexible and round, moving easily through your blood vessels. In sickle cell anemia, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.
There’s no cure for most people with sickle cell anemia. But treatments can relieve pain and help prevent problems associated with the disease.