Sickle Cell Disease

Introduction

This information leaflet aims to provide our patients who have sickle cell disease (SCD) and their carers and/ or family with a brief description and background about sickle cell disease, their management and the treatments available. Together with the discussion with our specialist team, we hope this information will help our patients with pain management, prevent complications and offer support to avoid or deal with painful crisis.

What is Sickle Cell Disease (SCD)

Sickle cell disease is a serious and lifelong health condition that affects the red blood cells and the haemoglobin they contain. Healthy red blood cells are round, disc shaped, flexible and can move through small blood vessels without any problems. Haemoglobin is the protein that carries oxygen to all parts of the body.

People with sickle cell disease produce unusually shaped red blood cells that can cause problems. The red cells become hard, rigid and sticky and they can become sickle shaped like a crescent called a “sickle”. These cells can block blood vessels causing severe painful episodes called “sickle cell crisis”.

In SCD the amount of haemoglobin and the number of normal red blood cells in your body is lower, causing anaemia. The cells are more fragile so they break down more easily than usual and they do not live as long as healthy blood cells. Damage from sickle cells can occur in vital organs including the kidneys, lungs or eyes. This can lead to high blood pressure, kidney problems, blindness, leg ulcers and damage to bones and joints.

SCD can only be inherited if both parents pass on a sickle cell gene. Although this is a serious condition, treatment can help manage many of the symptoms. Sickle cell disease is particularly common in people with an African, Caribbean, Mediterranean, Asian or Middle Eastern family background,but with the ever-growing diversity of the population, the disease can affect anyone.

The main symptoms of sickle cell disease:

• Painful episodes called sickle cell crisis, which can vary from mild to very severe pain and can last up to a week.
• An increased risk of serious conditions such as pneumonia, meningitis, infection in the blood or bone infections.
• Anaemia (where red blood cells cannot carry enough oxygen around the body), which can cause tiredness and shortness of breath (opens in a new tab).
• Can cause problems such as delayed growth, strokes, kidney and lung problems.
• A common symptom in babies and young children is when small bones in the fingers and toes become swollen and painful - this is known as dactylitis
• Episodes of tummy (abdominal) pain can occur if sickle cells block blood vessels in your abdomen
• Chest pain, high temperature (fever) and shortness of breath or fast breathing when there are blocked blood vessels in the lungs and can sometimes occur with a lung infection. This is acute chest syndrome and is very serious and should be treated urgently in hospital.
• Fever can occur in a sickle cell crisis without having an infection.
• Babies and small children may have more vague symptoms which can include being lethargic, restless, not feeding much or feeling generally unwell.
• For males of all ages - a persistent, painful erection of the penis called priapism caused by lack of oxygen supply to the area.

There are several treatments available to help manage sickle cell and prevent or treat its symptoms

• Drinking plenty of fluids around 2-3 litres daily.
• Good balance of nutrition and activity
• Staying warm and avoiding extremes of temperatures.
• Painkillers, such as paracetamol, codeine or ibuprofen (sometimes treatment with stronger painkillers in hospital may be necessary)
• Daily antibiotics to reduce your chances of getting an infection.
• Making sure infections are treated quickly.
• Making sure your routine immunisations are up-to-date::
  • pneumovax (given every 5 years)
  • haemophilus influenzae type b and meningococcal C
  • meningococcal ACWY conjugate
  • influenza (given every year)
• Taking folic acid for development of the red blood cells
• Avoiding smoking
• Exercises but avoiding extreme physical activity and exhaustion
• Attend your clinic appointment regularly so that your doctor can review your health and medications and monitor you for any complications.
• A medicine called hydroxycarbamide (hydroxyurea) to reduce symptoms and number of painful crises and acute chest syndrome. For the medicine to take effect it must be taken everyday for two to three months. A regular blood test is important to prevent toxicity.
• Regular blood transfusions if symptoms continue or get worse, or there are signs of damage caused by sickle cell disease

Treatment for SCD

Stem Cell or Bone Marrow Transplant

The only cure for sickle cell disease is a stem cell or bone marrow transplant (opens in a new tab) but they are not done very often and only used for severe SCD because of the risks involved and the availability of suitable donors.

Blood transfusion and exchange transfusion

Due to complications of sickle cell disease, an emergency blood transfusion is required when severe anaemia develops during a crisis. Some patients will also require regular blood transfusions or red cell exchanges.

Red blood cell exchange (RBCx) is a potentially lifesaving procedure that removes the sickled red cells and replaces them with healthy red blood cells.

This is needed in an emergency such as complicated sickle cell crisis or can be done as a routine or planned exchange transfusion to prevent sickle cell crisis and its complications. A single exchange transfusion before any major surgery also reduces the risk of complications from the general anaesthetic and surgery. It can also be performed during pregnancy to prevent complications to you and your baby or to correct anaemia and improve oxygen supply to your body reducing the possibility of sickle cell crisis.

The number of red cell exchanges will depend on the nature and severity of your condition and on how well you respond to treatment. For some patients they may form part of a long-term treatment programme. The red cell exchange takes between two and three hours depending on how much blood needs to be replaced. This is calculated according to your height, weight and blood counts and determines how long your treatment takes.

Preferably, red blood cell exchange is performed using a machine called a cell separator (apheresis machine) which can separate blood into its different parts. Through centrifuge, the machine separates and removes the red cell portion and the other blood components like white cells, platelets and plasma are returned together with the healthy donated red blood cells. In an acute setting where an automated service is unavoidably delayed or unavailable, manual exchange can also be performed.

After your consultant haematologist has discussed this procedure and its possible risks with you, we will ask you to sign a consent form to indicate that you are happy for the procedure to go ahead. In an emergency, this will be signed by your doctor for your best interest.

Red cell exchange transfusion is safely performed by specially trained nurses in our Apheresis Unit in Ward E10.

Iron Chelation Therapy

Blood contains iron. Regular blood transfusions cause accumulation of iron in the body. This is called iron overload. Iron cannot be removed by the body naturally, resulting in complications affecting the heart, the liver, and other vital organs. When this happens, it will result in serious complications.

Regular blood tests and scans are done to monitor and detect when the iron levels are raised and require treatment. Medication is needed to remove the iron from the body. This is called iron chelation therapy. They are used to remove iron from the body to reduce and prevent damage to organs.

There are three types of iron chelators which can be used alone or combined. These are:

1) Deferasirox (Exjade^®) taken in tablet form by mouth

2) Deferiprone (Ferriprox™) taken in tablet form by mouth

3) Desferrioxamine (Desferal^®) an infusion pump inserted under the surface of skin.

Hydroxycarbamide

This medicine works by increasing a special kind of haemoglobin called “foetal haemoglobin” (Hb F) which is normally present in newborn babies. A high foetal haemoglobin protects the red blood cells from turning into sickle cells by helping to keep them round and flexible, allowing them to move freely in the blood stream and reducing the clumping and blockages that result in sickle cell crises. It usually takes at least three months to feel the effect. Hydroxycarbamide also helps to keep the red cells well hydrated and less sticky by reducing the white cell count and improves the blood flow. This reduces the sickle cell symptoms, painful crises and acute chest syndrome’.

Planning for a family

Sickle cell disease is a genetically inherited condition. If you are planning to have a baby, you and your partner can meet a specialist or counsellor to discuss the chance of SCD being passed to your baby and the tests available to you. We can also review your medicines and vaccinations and make sure that your checks are up-to-date.

• Most women with SCD will have a straightforward pregnancy and a healthy baby and not have serious problems. However, painful crisis can be more common during pregnancy. Pregnant women have a higher risk of developing blood clots in the legs (venous thrombosis) compared with women who are not pregnant.
• If you are planning a pregnancy, a specialist team will look after you and your baby very closely during pregnancy.
• Having your baby before your due date is usually advised and you will be given support to breastfeed. This is to reduce the risks to you and your baby. You are also more likely to need a caesarean section. Your obstetrician and midwife will talk to you about your options.
• If you are taking hydroxycarbamide (hydroxyurea), you will be advised to stop taking it and continue using contraception for 3 months before you become pregnant. Your SCD team will also review any other medicines you are taking.
• You will be advised to take high-dose folic acid (5 mg) every day.
• SCD may also affect the growth of your baby because it can affect how your placenta works. In addition to your routine scans, you will have extra scans to check that your baby is growing normally.
• Blood transfusions are not routinely given during pregnancy, but may be needed. If so, this will be discussed with you.
• If you become unwell, contact your maternity unit as soon as possible so that you can be seen urgently by medical staff and given appropriate treatment. You will be monitored more closely and your baby’s wellbeing will also be checked.

If you think your condition may be life threatening call an ambulance. If you attend an Emergency Department (A&E) in another hospital and are admitted, show them your ED management plan.

Contacts/ Further Information

General Haematology Consultants:

Dr Martin Besser- Sickle Cell Lead Consultant

Dr Will Thomas

Dr Emily Symington

Dr Mark Robinson

General Haematology Secretary (01223 349280/ 01223 274652)

Haematology Specialist Nurses: 01223 217717

Ruth Jolley/ Vivian Garcia/ Raeesa Auturally

24 hour help and specialist advice 01223 245151 (CUH switchboard and ask for the on-call haematology registrar)

References

Sickle Cell screening (opens in a new tab)

NHS – Sickle cell anaemia (opens in a new tab)

Sickle Cell Society (opens in a new tab)

Sickle Cell and pregnancy (opens in a new tab)

Sickle Cell treatment (opens in a new tab)