Sickle-cell disease (SCD) is a group of inherited red blood cell (RBC) disorders. Healthy red blood cells are round and move through small blood vessels to carry oxygen to all parts of the body.
Sickle cell anemia causes red blood cells to become hard and sticky, and they have become sickle-shaped, or “C”. These affected cells die prematurely, which causes a constant shortage of red blood cells.
When traveling through small blood vessels, they can get stuck and block blood flow. This can cause pain and other serious problems.
Types of Sickle-cell Anemia
Most common types of sickle cell anemia:
- HbSS: people with this type of sickle cell disease inherit two sickle cell genes (“S”), one from each parent. This disease is commonly called “sickle cell anemia” (or sickle cell) and is usually the most severe form of the disease.
- HbS beta-thalassemia: people who have these types of sickle cell anemia inherit a gene for sickle cell and other genes from a type of abnormal hemoglobin. Hemoglobin is a protein that allows red blood cells to carry oxygen to all parts of the body. This type is usually a milder form of the disease.
- HbS beta-thalassemia: people with this type of sickle cell disease inherit one sickle cell gene and one beta-thalassemia, another type of anemia. There are two types of beta-thalassemia. “0” and “+”. Individuals with HbS beta thalassemia 0, frequently, have a severe form of the disease, whereas those with HbS beta + thalassemia tend to have a milder form.
There are also some rare sickle cell types:
HbSD, HBSE, HBSO: people with these types inherit one sickle cell gene and one sickle cell gene from one type of abnormal hemoglobin (“D”, “E”, or “O” ). Hemoglobin is a protein that allows red blood cells to carry oxygen to all parts of the body. These rare types of disease have different levels of severity. In general, the symptoms and complications are similar to those of People with sickle cell anemia “HbSS”.
Sickle cell trait:
HbAS : People with sickle cell disease inherit one sickle cell gene and one normal gene. This is called the sickle cell trait. Those with this trait are usually asymptomatic and live a normal life, but can pass the disease to their children. In addition, there are some rare health problems that may be potentially related to sickle cell trait.
Causes of Sickle cell anemia
Sickle cell anemia is a genetic condition that affects some newborns. It is inherited when the child receives two sickle cell genes, one from each parent.
Diagnosis of Sickle cell anemia
Sickle cell anemia is diagnosed with a simple blood test. It is most often found at birth during the tests that are performed on newborns routinely in the hospital. In addition, this disease can be diagnosed before birth.
Because children with sickle cell disease have a greater risk of infection and other health problems, it is important that the diagnosis is made and treatment started early.
You can call the local organization for sickle cell anemia to find out how to get screened.
Symptoms and treatment
People with sickle cell anemia symptoms during the first year of life, usually, five months. Symptoms and complications of sickle cell disease are different for each person and can range from mild to severe. No single treatment is best for all people with this disease. Treatment options vary depending on the symptoms presented by each person.
The only cure for sickle cell anemia is a bone marrow or stem cell (hematopoietic stem cell) transplantation. Bone marrow It is a soft fatty tissue found in the center of bones where blood cells are formed. A bone marrow transplant or stem cell transplant is a procedure that involves taking healthy cells that produce blood cells from a person (donor) and transplanting them into someone whose bone marrow is not working properly.
Transplants of bone marrow or stem cells are very risky and can cause serious side effects, even death. For the transplant to work, there must be a high level of compatibility between donor and recipient bone marrow. Usually, the best donor is a brother or sister. Transplants of bone marrow or stem cells are made only in cases of severe sickle cell disease in children in whom the disease has only caused minor damage to your organs.
Symptoms and treatment
People with sickle cell anemia symptoms begin during the first year of life, usually, five months. Symptoms and complications of sickle cell disease are different for each person and can range from mild to severe.
The reason why babies do not have symptoms at birth is that the hemoglobin fetal or “baby” prevents red blood cells become sickle (crescent-shaped). At about 4 or 5 months of age, fetal hemoglobin or “baby” it is replaced with sickle hemoglobin and begins to form when sickle cells.
No single treatment is best for everyone with sickle cell anemia. Treatment options vary depending on the symptoms of each person.
1.Hands and feet syndrome:
This is usually the first symptom of sickle cell anemia. Swelling of hands and feet, often accompanied by fever, is because sickle cells stick to blood vessels and block the flow of blood to and from the hands and feet.
Pain medications and fluids, such as water.
2. Episode or crisis of pain:
This is the most common complication and the main reason why people with sickle cell anemia go to the emergency room or hospital. When sickle cells travel through small blood vessels, they can get stuck and clog the blood circulation. This causes sudden pain, from mild to severe, which can last a long or short time.
There are simple steps they can take for people with sickle cell anemia to help prevent and reduce the number of painful crises:
- Drinking plenty of water.
- Try not to get overheated or too cold.
- Avoid high altitudes (air travel, climbing high mountains or cities).
- Avoid places or places with little oxygen (mountain climbing or exercising extremely hard, much like military camps or training for sports competitions).
- Adults with severe sickle cell disease can take a medicine called hydroxyurea to reduce the number of times it has a painful crisis.
- People taking hydroxyurea should be examined regularly by a doctor because this drug can cause serious side effects, including a higher risk of dangerous infections.
- New research has shown that babies and children with sickle cell anemia also benefit from hydroxy urea.
Most pain associated with sickle cell disease can be treated with pain medication OTC as ibuprofen or aspirin. Some people who have severe pain are administered daily opioid-based drugs (eg morphine) and other painkillers. Some people may be admitted to the hospital for intense treatment.
People with sickle cell disease do not benefit from iron supplements. This type of anemia is not caused by lack of iron in the blood, but by having an insufficient amount of red blood cells. Indeed, iron supplements can be harmful to a person with sickle cell anemia, because the extra iron builds up in the body and can cause damage to organs.
This is a very frequent complication. With sickle cell disease, red blood cells die prematurely. This means that there are not enough red blood cells to carry oxygen throughout the body. When this happens, a person can have:
- rapid heartbeat
- difficulty breathing
- bluish skin color
- jaundice (yellowing of the skin and whites of the eyes)
- slow growth
- delay in the onset of puberty
Blood transfusions are used to treat severe anemia. A common reason to require transfusion is the sudden worsening of anemia as a result of infection or an enlarged spleen. However, having multiple blood transfusions can cause health problems due to the iron content in the blood. Iron overload, called hemosiderosis, can damage the liver, heart, pancreas, and other organs, which can lead to diseases such as diabetes mellitus. The iron chelation therapy should be started in patients with sickle cell disease who receive regular blood transfusions to reduce excess iron levels.
People with sickle cell anemia, especially infants and children, are at increased risk for infections, especially those due to bacteria encapsulated by damage to the spleen. Pneumonia is a leading cause of death in infants and young children with sickle cell anemia.
- Vaccines can protect against dangerous infections.
- The vaccine against influenza (flu) every year after 6 months of age.
- Special pneumococcal vaccine (called 23-valent pneumococcal vaccine) at 2 and 5 years old.
- Pneumococcal conjugate vaccine (PCV13) in children aged 6-18 years old, if a child has not previously received.
- The meningococcal vaccine, if recommended by your doctor.
- In addition, children with sickle cell disease should receive a daily dose of penicillin, an antibiotic medicine to help prevent infection. This can begin to do at 2 months of age and continued until the child is at least five years.
- Adults with sickle cell disease should receive influenza vaccine annually, as well as pneumococcal and meningococcal, like other vaccines recommended by the doctor.
Infections are treated with antibiotic medicines and sometimes with blood transfusions. At the first sign of infection, such as fever, it is important that a person with sickle cell anemia, see your doctor immediately because it could represent for a medical emergency. Early treatment of an infection can help prevent problems.
5. Acute chest syndrome:
This can be fatal and must be treated in hospital. The symptoms and signs are similar to those of pneumonia. These include chest pain, coughing, shortness of breath and fever.
Adults with severe sickle cell disease can take a medicine called hydroxyurea to help prevent acute chest syndrome. People taking hydroxyurea should be closely monitored because this drug can cause serious side effects, including low white blood cell count, which increases the risk of certain types of dangerous infections.
A person should rest in bed or who have recently had surgery may use an incentive spirometer, also called “bottle blow” to help prevent acute chest syndrome.
Treatment, depending on the cause may include oxygen, medicines to treat infections, drugs to dilate the airways and improving air flow and blood transfusions.
6. Splenic sequestration:
This can be fatal so it should be treated in a hospital. This occurs when a large number of sickle cells are trapped in the spleen and produce their sudden enlargement. Symptoms may include sudden weakness, pale lips, rapid breathing, extreme thirst, abdominal pain (stomach) or on the left side of the body and rapid heartbeat.
Parents of a child with sickle cell disease should learn to sense and measure the spleen size of your child and get help if you have an enlarged spleen.
Patients who have had a serious episode of splenic sequestration or who have had many episodes in the past, may need periodic blood transfusions or that they have to remove the spleen (splenectomy) to prevent new crises.
Usually, blood transfusions are the treatment to follow. This should be done in consultation with a hematologist (blood diseases) because patients sometimes have fluid overload when blood is released to the spleen. It may be necessary to remove blood to prevent this from happening.
7. Loss of sight:
The loss of vision, including blindness, can occur when the sickle cells block the blood vessels of the eye damaging the retina (the thin layer of tissue found inside the back of the eye). Some patients had additional blood vessels form around the eyes from lack of oxygen.
People with sickle cell anemia eyes should be checked annually to determine if there is damage to the retina. If possible, this review must be done by a specialist ophthalmologist in diseases of the retina.
If there is damage to the retina by an overgrowth of blood vessels, laser treatment often can prevent further vision loss.
8. Leg ulcers:
This usually occurs on the lower legs. Often they affect more men than women and usually appear between 10 and 50 years. A combination of factors cause ulcers, such as trauma, infection, inflammation, and disruption of circulation in the smallest blood vessels in the leg.
The leg ulcers can be treated with prescription creams and ointments. These ulcers can be painful and patients may give them strong pain medications. Treatment of leg ulcers may also consist in the use of cultured skin grafts. This treatment is done in specialized centers. Bed rest and keeping legs elevated reduces inflammation, although not always possible.
A stroke can occur when sickle cells accumulate in the blood vessels and prevent blood flow to the brain. About 10% of children with sickle cell anemia suffer a symptomatic stroke. Strokes can cause learning problems and disabilities for life.
Children at risk of stroke can identification by using a special type of test called transcranial Doppler (TCD, for its acronym in English) ultrasound. If it is determined that the child has an abnormal TCD, your doctor may recommend frequent blood transfusions to help prevent a stroke. People who receive frequent blood transfusions should be watched carefully as they can have serious side effects. For example, you may accumulate excess iron in the body and cause damage to organs that are potentially fatal.
10. Deep vein thrombosis and pulmonary embolism (DVT / PE):
The deformation of the red blood cells can increase the blood coagulation and induce an increased risk of a blood clot in a deep vein (DVT deep vein thrombosis) or lungs (EP, pulmonary embolism) if the blood clot travels from the deep veins. People with sickle cell anemia have a high probability of DVT or PE. DVT and PE can cause serious illness, disability and sometimes even death.
Prevention and treatment:
Drugs are used to prevent and treat DVT and PE. The EP requires immediate medical attention.
Other possible complications:
- Damage to body organs (such as liver, heart, and kidneys), tissues or bones due to inadequate blood flow to the affected areas.
- The malnutrition and stunted growth in adolescents can cause delayed puberty and in men, infertility.
- Kidney stones.
- Painful penile erections, called priapism, which can last from less than two hours to more than 4 hours. If they last longer than 4 hours, the person should receive urgent medical attention. The disorder can lead to impotence.
New Emerging treatments:
There is no widely available cure for sickle cell anemia. We are currently evaluating several new emerging treatments. For young patients with sickle cell, acute one option could be a stem cell transplant, including bone marrow transplantation in a patient with sickle cell anemia, with healthy bone marrow from a donor, ideally a brother without sickle cell anemia. However, although bone marrow transplant can cure sickle cell anemia in a small number of patients, other patients may have side effects that threaten life.
Other emerging new therapies are gene therapy (to induce the formation of normal red blood cells in the bone marrow) and new drugs (to stimulate the production of fetal hemoglobin or to prevent red blood cells to become sickle.