A Potential Cure for Sickle Cell Anemia
A promising new treatment for sickle cell anemia, developed by the National Institutes for Health and validated by a new study by the University of Illinois at Chicago, holds out the prospect of a cure for this chronic disease.
In the United States, sickle cell primarily affects African-Americans. It's a debilitating condition that causes fatigue, chronic pain and even death. For those who have the disease, most will not live to see their 50th birthday, with the average life expectancy shortened by more than 30 years.
Dr. Santosh Saraf, one of the co-authors of the UIC study, joins us to discuss these groundbreaking developments.
What is sickle cell anemia?
Sickle cell anemia is an inherited condition in which red blood cells—which are flexible and round in healthy bodies—become rigid, sticky and shaped like sickles or crescent moons, according to the Mayo Clinic.
These misshapen sickle cells can get stuck in blood vessels, causing blood flow to slow down or even get blocked – along with oxygen -- from parts of the body.
In the United States, it’s required that every baby is tested for sickle cell anemia as part of a screening process for newborns. The disease can also be detected before a baby is born by taking a sample of amniotic fluid as early as 8-10 weeks into a pregnancy, according to the National Heart, Lung, and Blood Institute.
Who’s at risk of inheriting the disease?
Sickle cell anemia is caused by a gene mutation which must be carried by both parents in order for a child to be born with the disease. However, there is only a 25 percent chance that a child born to parents who are sickle cell carriers will develop sickle cell anemia.
Most Americans with sickle cell disease are of African ancestry, with 1 in every 500 black children born with the disease.
“The sickle cell gene developed in malaria endemic regions, so if you look around the globe around the equator—wherever malaria is present—you’ll see that the sickle gene is there, and it is actually protective if you inherit one of the two sickle genes. It helps protect you from fetal malaria,” said Dr. Santosh Saraf, an assistant professor of medicine in the division of hematology/oncology at the University of Illinois Hospital & Health Sciences System. “So you will see it commonly in Africa, the Middle East, in the Mediterranean region and in India.”
What are the symptoms?
Symptoms of sickle cell anemia usually appear after four months of age and can include:
- Anemia: A lack of healthy red blood cells, which can cause fatigue.
- Jaundice: A yellowing of the skin or whites of the eyes.
- Acute pain: Periodic episodes of pain, called crises, develop when sickle-shaped blood cells block blood flow through blood vessels to the chest, abdomen and joints. Pain can also occur in bones. Crises can last for a few hours to a few weeks.
- Hand-foot syndrome: Swollen hands and feet caused by sickle cells blocking blood flow to those extremities.
- Infections: Sickle cells can damage the spleen, an infection-fighting organ, making people more susceptible to infections.
- Delayed growth: Sickle cell anemia can cause delayed growth in infants and children, as well as delay puberty in teens.
- Vision problems: Sickle cells can cause damage to a person’s retina.
Sickle cell anemia can also lead to many complications, including
- Acute chest syndrome: Sickle cell anemia causes chest pain, fever and difficulty breathing
- Pulmonary hypertension
- Organ damage
- Skin ulcers
- Deep Vein Thrombosis
- Pulmonary embolism
Below, watch a video by the American Society of Hematology highlighting a patient’s journey with sickle cell disease.
What treatments are available?
Most sickle cell anemic complications are treated as they occur. These treatments include antibiotics, vitamins, blood transfusions, medication and surgery (to correct problems associated with vision or to remove a damaged spleen, for example).
Hydroxyurea, an oral medication, is the only FDA approved treatment for sickle cell anemia. The medication has been shown to reduce or prevent disease-related complications. Patients’ white blood cell and platelet counts must be closely monitored because the drug can lower those counts to dangerous levels, according to Saraf.
While a stem cell transplant (aka a bone marrow transplant) is another treatment option, there are risks associated with replacing bone marrow affected by sickle cell anemia with healthy bone marrow from a donor.
First, a patient must undergo radiation or chemotherapy to destroy the sickle cells. The healthy stem cells are then injected intravenously into the bloodstream of the person with sickle cell anemia. After the transplant, the patient must take medication to prevent the rejection of donated stem cells.
Stem cell transplants have been primarily used to treat children because chemotherapy was deemed too risky for adults.
“The regimen in children uses pretty intense chemotherapy that kind of empties the bone marrow out to give space for the new stem cells. The problem is that with increasing age the organs are all being damaged by these sickled cells, so after a certain age the toxicity of the chemotherapy is not handled as well and even mildly reduced chemotherapy in adults have led to graft-versus-host disease and even death. So it’s thought that it’s too dangerous to do these regimens with adults with sickle cell disease,” Saraf said.
Now, there’s a promising new treatment for adults developed by the National Institutes of Health that doesn’t require the use of chemotherapy. With the new procedure, patients receive immunosuppressive drugs, along with a small dose of body irradiation, prior to stem cell transplantation. A recent study of 13 patients that received this treatment yielded promising results.
“As soon as one month after the transplant, we’ve been administering surveys for the patients, and in that one month we’ve seen improvements recorded for that patient’s quality of life and that reported quality of life continues to improve one year out from the transplant,” Saraf said.