Sickle Cell Disease

The primary symptom of sickle cell disease is episodes of pain called “crises” or “pain crises,” which occur when sickled cells block blood vessels. These painful episodes can affect any part of the body but commonly strike the chest, abdomen, joints, and bones. The pain can range from mild to severe and may last hours to days, sometimes requiring hospitalisation.

Beyond pain crises, people with sickle cell disease often experience fatigue, jaundice (yellowing of the skin and eyes), delayed growth, susceptibility to infections, and vision problems. Long-term complications can include stroke, acute chest syndrome, pulmonary hypertension, organ damage (particularly to the spleen, kidneys, and liver), leg ulcers, and priapism (painful erections). Symptoms typically begin in early childhood, often around 5-6 months of age after foetal haemoglobin is replaced by sickle haemoglobin.

In the UK, sickle cell disease is primarily diagnosed through the NHS Sickle Cell and Thalassaemia Screening Programme, which offers universal newborn screening as part of the routine heel prick test performed on all babies between 5-8 days after birth. This early screening allows for prompt identification of affected infants before symptoms develop, enabling healthcare providers to implement preventative care immediately.

For antenatal testing, the NHS offers blood tests to pregnant women and their partners to determine if they carry the sickle cell trait. When both parents are carriers, diagnostic testing of the foetus can be conducted through chorionic villus sampling (CVS) at 11-14 weeks of pregnancy or amniocentesis at 15-20 weeks. Additionally, preconception genetic testing is available for couples planning pregnancies who wish to understand their carrier status before conceiving.

Currently, the only established cure for sickle cell disease is a stem cell or bone marrow transplant, also known as haematopoietic stem cell transplantation (HSCT). This procedure replaces the affected person’s bone marrow with healthy stem cells from a compatible donor, typically a sibling who doesn’t have sickle cell disease. When successful, the transplant enables the body to produce normal red blood cells instead of sickled ones.

However, stem cell transplants are not suitable for everyone due to the difficulty in finding matching donors and the significant risks involved, including serious infections, graft rejection, and graft-versus-host disease. Promising new gene therapy treatments are being developed that may offer curative options in the future by modifying the patient’s own stem cells to produce functional haemoglobin. Several clinical trials for gene therapy approaches have shown encouraging results, with some patients achieving sustained production of healthy red blood cells without the need for donor cells.

The day-to-day management of sickle cell disease in the UK focuses on preventing complications and treating symptoms as they arise. Preventative measures include taking daily penicillin (or alternative antibiotics) to reduce the risk of serious infections, maintaining up-to-date vaccinations, staying well-hydrated, avoiding extreme temperatures, and getting regular check-ups with sickle cell specialists. Many patients also take hydroxyurea (hydroxycarbamide), a medication that increases foetal haemoglobin production and reduces the frequency of painful crises.

When pain crises occur, treatment typically involves pain management with paracetamol, NSAIDs, and sometimes stronger opioid medications for severe pain. Hospital treatment may be necessary for complicated crises and involves intravenous fluids, strong pain relief, oxygen therapy, and antibiotics if infection is suspected. Some patients require regular blood transfusions to reduce the percentage of sickled cells and prevent complications such as stroke. Comprehensive care is typically provided through specialist sickle cell centres within the NHS, offering multidisciplinary support including haematologists, specialist nurses, psychologists, and social workers.

People with sickle cell trait have inherited one sickle cell gene and one normal gene, making them carriers of the condition rather than having the disease itself. Under normal circumstances, people with sickle cell trait do not develop sickle cell disease and typically experience few or no health problems related to the trait. Their red blood cells contain both normal and sickle haemoglobin, but the normal haemoglobin is usually sufficient to prevent the blood cells from forming the characteristic sickle shape.

However, it’s worth noting that under certain extreme conditions such as severe dehydration, high altitude, or intense physical exertion, people with sickle cell trait may rarely experience complications related to sickling of red blood cells. These uncommon events might include muscle breakdown (rhabdomyolysis), blood in the urine (hematuria), or splenic infarction. The primary significance of sickle cell trait is for family planning, as carriers have a 50% chance of passing the trait to each of their children. If both parents have the trait, there’s a 25% chance their child will have sickle cell disease.

Pregnancy for women with sickle cell disease requires careful planning and specialist care due to increased risks for both mother and baby. Women with the condition face higher rates of pain crises during pregnancy, as well as increased risk of pre-eclampsia, gestational diabetes, restricted foetal growth, premature labour, and stillbirth. The physiological changes of pregnancy, including increased blood volume and oxygen demand, can exacerbate sickle cell complications.

In the UK, pregnant women with sickle cell disease receive joint care from haematologists and obstetricians experienced in high-risk pregnancies. Management typically includes more frequent antenatal appointments, regular blood tests, growth scans, and sometimes prophylactic blood transfusions to reduce complications. Some medications used for sickle cell disease, such as hydroxyurea, are typically discontinued during pregnancy due to potential risks to the foetus. Despite these challenges, with proper specialised care, most women with sickle cell disease can have successful pregnancies and healthy babies.

Life expectancy for people with sickle cell disease in the UK has improved significantly over recent decades thanks to advances in treatment, comprehensive care, and newborn screening. Currently, many people with sickle cell disease in the UK can expect to live into their 50s, 60s, or beyond, though this varies depending on the severity of the condition, compliance with treatments, and access to specialised care.

The NHS provides dedicated sickle cell centres that offer multidisciplinary care, helping to prevent and manage complications that historically reduced life expectancy. Early interventions, including prophylactic antibiotics starting in infancy, comprehensive vaccination programmes, hydroxyurea therapy, and transcranial Doppler screening to prevent strokes, have all contributed to improved outcomes. However, life expectancy remains somewhat reduced compared to the general population, particularly for those with more severe forms of the disease or those who experience serious complications such as stroke, pulmonary hypertension, or kidney failure.

Sickle cell disease affects approximately 1 in 2,000 live births in the UK, making it the most common serious genetic condition in the country. The NHS estimates that there are between 12,500 and 15,000 people living with sickle cell disease across the United Kingdom, with the highest prevalence in urban areas with significant populations of African and Caribbean descent.

In the UK, the prevalence of sickle cell trait (carriers) is approximately 1 in 10 to 1 in 4 people of African or Caribbean background, and about 1 in 100 in the wider population. The distribution of sickle cell disease is not uniform across the country, with London having the highest concentration—approximately 70% of all UK cases. This geographic distribution has influenced the development of specialist sickle cell centres, with the most comprehensive services being located in London and other major cities with higher prevalence rates.

Sickle cell crises can be triggered by various factors that increase the body’s demand for oxygen or lead to dehydration, both of which promote the sickling of red blood cells. Common triggers include infections, cold weather, high altitude, strenuous exercise, dehydration, alcohol consumption, and psychological or physical stress. In some cases, crises may occur without any identifiable trigger, making the condition unpredictable and challenging to manage.

Prevention of crises focuses on avoiding known triggers and maintaining good overall health. The NHS recommends that people with sickle cell disease stay well-hydrated (drinking at least 8-10 glasses of water daily), avoid extreme temperatures, exercise moderately while taking regular breaks, get sufficient rest, manage stress effectively, and avoid smoking and excessive alcohol consumption. Additionally, prompt treatment of infections, adherence to prescribed medications like hydroxyurea, and regular check-ups with healthcare providers are essential preventative measures. Many patients develop personalised crisis prevention plans with their healthcare team, which include early warning signs to watch for and specific actions to take when symptoms begin.