Sickle cell disease, also known as sickle cell anemia, is an inherited disorder that affects an estimated 100,000 Americans. It is most common among African Americans and Hispanics. Currently, the only potentially curative treatment available for sickle cell disease is blood or bone marrow transplant.
The University of Kansas Cancer Center is uniquely qualified to support patients with sickle cell disease through transplant. One of just 71 National Cancer Institute-designated cancer centers in the nation, we offer unparalleled expertise in using blood and marrow transplant to treat both cancerous and noncancerous blood disorders, including sickle cell disease. In our program’s history, our team has performed more than 3,700 transplant procedures, including the first in Kansas to treat adult sickle cell disease.
What is sickle cell disease?
In healthy red blood cells, hemoglobin carries oxygen, creating a smooth, round cell shape. With sickle cell disease, defective hemoglobin causes red blood cells to become stiff, taking on a sickle or crescent shape that blocks blood flow. While normal blood cells live 90-120 days, sickle cells only last 10-20 days. Making new cells at this rate becomes difficult for the body, resulting in reduced red blood cells and anemia. In addition, sickle cells can stick to blood vessel walls, stopping or slowing the flow of blood. When this occurs, oxygen cannot reach the nearby tissue. This can cause sudden and severe pain.
A defective gene called the sickle cell gene is responsible for the disease. People with sickle cell disease are born with 2 sickle cell genes, 1 from each parent. If you only receive 1 sickle cell gene, you have what is called sickle cell trait. When this occurs, you are generally healthy and do not develop symptoms; however, you can pass the gene on to your children.
Symptoms and risks of sickle cell disease
Because it is a genetic disease, your biggest risk factor is having 2 sickle cell genes. In the United States, the most cases of sickle cell disease affect African Americans or Hispanics. About 1 in 13 African American babies are born with the sickle cell trait while 1 in 365 are born with the disease.
In the United States, most parents learn their child has sickle cell disease long before symptoms even start. Every state in the U.S. tests for sickle cell disease at birth and notifies parents before symptoms occur. Symptoms typically start around 6 months of age and include:
- Jaundice and icterus, or a yellowing of the skin and eyes
- Fatigue and fussiness from the anemia
- Dactylitis, or painful swelling in the hands and feet
As sickle cell disease progresses, the symptoms can vary from person to person. Acute and chronic symptoms as well as common complications often occur and include:
When the cells stick to the blood vessel walls and disrupt the delivery of oxygen to tissue, acute severe pain occurs. This can be sharp, intense, stabbing or throbbing pain. The most common areas of pain include the abdomen, arms, chest, lower back and legs.
In addition to acute pain episodes, many teens and adults living with sickle cell disease also suffer from chronic pain.
Anemia in people with sickle cell disease is usually mild to moderate. However, severe anemia can occur and be life-threatening.
Sickle cells often damage the spleen, an organ necessary for fighting infections. With a damaged spleen, people have increased risk of infections such as meningococcus, staphylococcus, salmonella and haemophilus influenza type B.
When sickle cells infect the lungs, oxygen levels drop. This causes damage to the lung tissue and can result in chest pain, coughing, fever, shortness of breath and rapid breathing.
When oxygen delivery to the brain slows or stops, this can result in a stroke or stroke-like symptoms. This can include memory issues, difficulty thinking and processing information and more.
A lack of oxygen delivery from sickle cell disease can damage the blood vessels and retinas in the eye. This can cause light-sensitivity as well as visual impairment or loss.
Lack of oxygen in the blood vessels can contribute to heart problems, such as an enlarged heart. Frequent blood transfusions can also contribute to heart damage.
Damage from sickle cells in the blood vessels of the lungs can make it harder for the heart to pump blood to this area, causing an increase in lung blood vessel pressure. This can cause shortness of breath and fatigue.
The kidneys are sensitive to changes in the blood by sickle cells and this can affect the production of concentrated urine. As a result, you may experience frequent or uncontrolled urination. Liver damage is also common.
As the disease progresses, small sores can develop on the legs. While some will heal quickly, others can take long time periods to heal or not heal at all.
Sickling in the bones can also occur and is most common in the bones of the hip, shoulder, knees and ankles. This occurs in teens and adults and can lead to severe joint damage or the need for joint replacement.
Diagnosis and screening for sickle cell disease
All newborns in the U.S. undergo a blood test to screen for sickle cell disease. This test can also be done before the baby is born through amniotic fluid. As an adult, you can learn with a simple blood test whether you have the sickle cell genes.
A future without limits
Sickle cell disease treatments
Treatments for sickle cell disease focus on managing complications. Hydroxyurea is an oral medication that reduces or prevents many different complications. Blood transfusions increase the number of red blood cells in the body and help reduce the risk of blockages and anemia.
A blood and marrow transplant is currently the only potential cure for some people. Transplants typically occur in children with a matched donor, but only 1 in 10 children have a matched donor who does not have sickle cell disease or trait. Transplants are more risky for adults.