What is Sickle Cell Disease?
WHAT IS SICKLE CELL DISEASE
Sickle cell disease (SCD) is common throughout much of sub-Saharan Africa, affecting up to 3% of births in parts of the continent. It occurs more often among people from parts of the world where malaria is or was common. It is believed that people who carry the sickle cell trait are less likely to have severe forms of malaria. Despite being named a unglobal public health priority in 2008, it remains a low priority for many African countries. The most common form of SCD is caused by homozygosity for the β-globin S gene mutation (SS disease). It is widely believed that this condition is associated with very high child mortality, but reliable contemporary data are lacking.
Africa bears the most of the world’s burden of sickle cell disease. where it is a major contributor to child morbidity and mortality with approximately 240,000 children born with sickle cell each year. Inspite of the low cost of various preventative care protocols, there’s significant lack of sufficient recourses allocated to sickle cell care across African countries and this has affected the alleviation of the burden of sickle cell lagging behind in other public health efforts in the continent. Nigeria currently bears the highest burden of sickle cell in Africa with approximately 50 million people directly affected by the disease. Historically, in the absence of newborn screening and appropriate treatment, most children born with SCD die undiagnosed in early childhood. However, with increasing awareness of the condition and economic and epidemiologic transition, increasing numbers are surviving.
Greater investment in basic and applied research in the African context, and increased sensitization of African ministries of health regarding the importance of this condition, could make a substantial difference to the lives and livelihoods of millions of people living with sickle cell disease in the continent and their families.
Sickle cell disease is most common among people from Africa, India, the Caribbean, the Middle East, and the Mediterranean.
Sickle Cell Signs & Symptoms
Sickle cell disorder (SCD) is a genetic disorder. SCD affects the red blood cells which become stiff and sticky and block passage through blood vessels, sometimes getting stuck and forming clumps. This brings on a ‘sickling crisis’ that can be very painful. It can also lead to infections and organ damage, potentially causing serious complications such as stroke or blindness.
Symptoms of sickle cell anemia usually show up at a young age. They may appear in babies as early as 4 months old, but generally occur around the 6-month mark.
While there are multiple types of SCD, they all have similar symptoms, which vary in severity. These include:
- excessive fatigue or irritability, from anemia
- fussiness, in babies
- bed-wetting, from associated kidney problems
- jaundice, which is yellowing of the eyes and skin
- swelling and pain in hands and feet
- frequent infections
- pain in the chest, back, arms, or legs
SCD can cause severe complications, which appear when the sickle cells block vessels in different areas of the body. Painful or damaging blockages are called sickle cell crises. They can be caused by a variety of circumstances, including:
- changes in temperature
- poor hydration
Complications arise due to SCD
Anemia is a shortage of RBCs. Sickle cells are easily broken. This breaking apart of RBCs is called chronic hemolysis. RBCs generally live for about 120 days. Sickle cells live for a maximum of 10 to 20 days.
Hand-foot syndrome occurs when sickle-shaped RBCs block blood vessels in the hands or feet. This causes the hands and feet to swell. It can also cause leg ulcers. Swollen hands and feet are often the first sign of sickle cell anemia in babies.
Splenic sequestration is a blockage of the splenic vessels by sickle cells. It causes a sudden, painful enlargement of the spleen. The spleen may have to be removed due to complications of sickle cell disease in an operation known as a splenectomy. Some sickle cell patients will sustain enough damage to their spleen that it becomes shrunken and ceases to function at all. This is called autosplenectomy. Patients without a spleen are at higher risk for infections from bacteria such as Streptococcus, Haemophilus, and Salmonella species.
Delayed growth often occurs in people with SCD. Children are generally shorter but regain their height by adulthood. Sexual maturation may also be delayed. This happens because sickle cell RBCs can’t supply enough oxygen and nutrients.
Priapism is a lingering, painful erection that can be seen in some men with sickle cell disease. This happens when the blood vessels in the penis are blocked. It can lead to impotence if left untreated.
Gallstones are one complication not caused by a vessel blockage. Instead, they are caused by the breakdown of RBCs. A byproduct of this breakdown is bilirubin. High levels of bilirubin can lead to gallstones. These are also called pigment stones.
Seizures, strokes, or even coma can result from sickle cell disease. They are caused by brain blockages. Immediate treatment should be sought.
Blindness is caused by blockages in the vessels supplying the eyes. This can damage the retina.
Skin ulcers in the legs can occur if small vessels there are blocked.
Heart disease and chest syndrome
Since SCD interferes with blood oxygen supply, it can also cause heart problems which can lead to heart attacks, heart failure and abnormal heart rhythm.
Damage to the lungs over time related to decreased blood flow can result in high blood pressure in the lungs and scarring of the lungs. These problems can occur sooner in patients who have sickle chest syndrome. Lung damage makes it more difficult for the lungs to transfer oxygen into the blood, which can result in more frequent sickle cell crises.
Sickle chest syndrome
Sickle chest syndrome is a severe type of sickle cell crisis. It causes severe chest pain and is associated with symptoms such as cough, fever, sputum production, shortness of breath, and low blood oxygen levels. Abnormalities observed on chest X-rays can represent either pneumonia or death of lung tissue (pulmonary infarction). The long-term prognosis for patients who have had sickle chest syndrome is worse than for those who have not had it.
SICKLE CELL DIAGNOSTIC TESTING
All newborns in the United States are screened for sickle cell disease. Prebirth testing looks for the sickle cell gene in your amniotic fluid.
In children and adults, one or more of the following procedures may also be used to diagnose sickle cell disease.
Detailed patient history
This condition often first appears as acute pain in the hands and feet. Patients may also have:
- severe pain in the bones
- painful enlargement of the spleen
- growth problems
- respiratory infections
- ulcers of the legs
- heart problems
Your doctor may want to test you for sickle cell anemia if you have any of the symptoms mentioned above.
Several blood tests can be used to look for SCD:
- Blood counts can reveal an abnormal Hb level in the range of 6 to 8 grams per deciliter.
- Blood films may show RBCs that appear as irregularly contracted cells.
- Sickle solubility tests look for the presence of Hb S.
Hb electrophoresis is always needed to confirm the diagnosis of sickle cell disease. It measures the different types of hemoglobin in the blood.
Sickle Cell Treatment
A number of different treatments are available for SCD:
- Rehydration with intravenous fluids helps red blood cells return to a normal state. The red blood cells are more likely to deform and assume the sickle shape if you’re dehydration.
- Treating underlying or associated infections is an important part of managing the crisis, as the stress of an infection can result in a sickle cell crisis. An infection may also result as a complication of a crisis.
- Blood transfusions improve transport of oxygen and nutrients as needed. Packed red cells are removed from donated blood and given to patients.
- Supplemental oxygen is given through a mask. It makes breathing easier and improves oxygen levels in the blood.
- Pain medication is used to relieve the pain during a sickle crisis. You may need over-the-counter drugs or strong prescription pain medication like morphine.
- (Droxia, Hydrea) helps to increase production of fetal hemoglobin. It may reduce the number of blood transfusions.
- Immunizations can help prevent infections. Patients tend to have lower immunity.
Bone marrow transplant has been used to treat sickle cell anemia. Children younger than 16 years of age who have severe complications and have a matching donor are the best candidates.
There are things you can do at home to help your sickle cell symptoms:
- Use heating pads for pain relief.
- Take folic acid supplements, as recommended by your doctor.
- Eat an adequate amount of fruits, vegetables, and whole-wheat grains. Doing so can help your body make more RBCs.
- Drink more water to reduce the chances of sickle cell crises.
- Exercise regularly and reduce stress to reduce crises, too.
- Contact your doctor immediately if you think you have any type of infection. Early treatment of an infection may prevent a full-blown crisis.
Support groups can also help you deal with this condition.
SCD Long Term Outlook
The prognosis of the disease varies. Some patients have frequent and painful sickle cell crises. Others only rarely have attacks.
Sickle cell anemia is an inherited disease. Talk to a genetic counselor if you’re worried that you might be a carrier. This can help you understand possible treatments, preventive measures, and reproductive options.