Sickle cell disease has long been treated as a lifelong condition. But the genetic blood disorder is entering a new era with bone marrow transplants and newly FDA-approved gene therapies offering the possibility of long-term remission or even a cure for some patients.
The problem, as always, is affordability and accessibility.
Sickle cell is an inherited condition that affects about 100,000 individuals in the U.S. About 90% are Black, but it is not a “Black disease.” Rather, it developed in the hemoglobin, a blood protein that carries oxygen through the body, to protect against malaria, a deadly mosquito-borne infectious disease.
“The cell learned to adapt in those areas to protect against infection from malaria,” Dr. Ali Sanati Mehrizi, a pediatric hematologist, said recently on WUSF’s “Florida Matters Live & Local.”
That includes tropical and subtropical regions such as sub-Saharan Africa, Southeast Asia and South America.
"Anywhere that the blood flow has been affected could manifest as pain," he said. “The pain sometimes is the manifestation of the cells that should be receiving that blood flow and are not there essentially dying off, and so to come to their rescue, the inflammatory process that comes to help those cells can lead to the pain symptoms the patients are experiencing.”
Most people make hemoglobin-A, the adult form of hemoglobin. People with sickle cell have a genetic change that leads them to produce hemoglobin-S, an altered form that can cause red blood cells to become rigid and take on a sickle shape. Unlike healthy red blood cells, which can bend and move through tiny blood vessels, sickled cells can get stuck and restrict blood flow.
“In people with sickle cell disease, hemoglobin “twists on itself and becomes like a tight rope, or like a braid,” he said.
Organ damage occurs over time, contributing to pain crises, kidney problems, lung complications, brain complications and severe anemia.
“Hemoglobin-S has some protective effects in that the red blood cells that produce sickled hemoglobin are less likely to be infected by malaria,” the doctor added, “and so that is one of the protective effects that is basically the evolutionary reason as to why sickle hemoglobin persists in patients who are from countries where malaria is endemic.”
Skipping generations
In Florida and other states, newborn screening programs test for sickle cell disease at birth, allowing doctors to identify affected infants within days of delivery.
“The sooner you can prevent complications, the better the patients do,” Sanati Mehrizi said.
Children with sickle cell disease should establish care with a hematologist by about 2 months of age.
“Start the process in preventive care to make sure that they can optimize their health and wellness throughout their life,” he said.
Sanati Mehrizi also said the condition can run in families without being obvious for generations, because many people carry only the sickle cell trait without symptoms.
“Understanding what that means, in terms of family planning, is really important,” he said, including carrier screening when planning a family and understanding the risk of having a child the disorder. “So that it doesn't come to you as a shock if and when you have a child with sickle cell disease.”
Most patients are treated from birth with medications such as hydroxyurea and care aimed at reducing complications. The cost can be substantial. A GoodRx analysis found lifetime treatment costs can exceed $1.6 million, and for people with commercial insurance, out-of-pocket costs over a lifetime can surpass $40,000.
A day in the life of a sickle cell patient means trying to stay as healthy as possible, he said.
“In children, we use antibiotics that prevent infections, we make sure their vaccinations are given on time,” Sanati Mehrizi said. “There are certain additional vaccines that children with sickle cell disease must receive, in addition to normal childhood vaccinations on a day-to-day basis.”
He urged people to support organizations that assist patients and families and to donate blood, which is often essential for patients who require repeated transfusions.
“Sickle cell disease patients often need transfusions, and the more they get transfusions, the trickier it is to transfuse them,” the doctor said. “So, the more mixed the donor pool is, the better, the easier it is to find.”
CRISPR enters the picture
For years, bone marrow transplant has been the only curative option for sickle cell disease, but it is limited to patients with suitable donors. New gene therapies offer a similar curative goal using a patient’s own cells, potentially expanding access.
Knowing family history is vital if deciding on a bone marrow transplant, a procedure that replaces a patient’s stem cells with a donor’s healthy blood-forming cells. Sanati Mehrizi said the process typically involves chemotherapy followed by infusion of donor bone marrow from a parent, sibling or unrelated donor.
“With a new set of bone marrow from a donor … we can put the donor's bone marrow into the patients, and the patients can be cured of their disease,” he said.
The procedure is expensive – albeit a fraction of the gene therapies – and carries risks, including rejection and infection, and finding a matching donor can be difficult.
Hence, the excitement for two gene therapies recently approved for use in the United States.
One, called Casgevy, uses CRISPR gene editing to modify a patient’s own blood-forming stem cells so the body can produce healthier hemoglobin and prevent red blood cells from sickling. The other, Lyfgenia, uses a different approach to help red blood cells carry oxygen more normally and reduce the painful and sometimes life-threatening complications of the disease
Both are one-time procedures that involve collecting a patient’s stem cells, modifying or replacing them in a lab. Chemotherapy is used to clear out existing bone marrow cells so the genetically modified cells can be implanted.
“The gene therapy products are quite expensive,” Sanati Mehrizi said. “One of them is a little over $2 million. The other one is about $3 million. But, obviously, that much of that cost will be covered by insurance. But those are the list prices of the therapies.”
Nonprofits can provide financial assistance, but a breakthrough involves a new payment model involving Medicaid, in which the federal government negotiates the cost of therapy with pharmaceutical companies on behalf of state Medicaid programs — and then holds them accountable for the treatment’s success. Florida is among the participating states.
“The gene therapy products are available in about 40 to 50 centers nationwide. So, if you're interested, we can always connect you with centers that are doing them,” said Sanati Mehrizi, who practices with Tampa General Hospital and USF Health.
Sharing days of awareness
It is likely many people who just observed Juneteenth were unaware that World Sickle Cell Day also fell on June 19.
The alignment is a historical coincidence, yet it holds deep significance for health equity in the Black community.
While Juneteenth marks the day in 1865 when enslaved people in Galveston, Texas, finally learned of their freedom, World Sickle Cell Day was established much later by the United Nations in 2008 to raise global awareness for the disorder. Juneteenth was made a federal holiday in 2021.
Community organizations and healthcare advocates can raise voices for African American resilience while addressing systemic health disparities, often hosting joint educational events and blood drives.
Sanati Mehrizi stressed the need for more people to appreciate the disease and those living with it.
“I would encourage people to learn about it. Many of your neighbors, your colleagues may have it,” he said. “Understanding what they're going through may help you realize why they may not be coming to school or coming to work that day.”
For more information and resources on sickle cell disease, go to websites of the Sickle Cell Society or Sickle Cell Disease Association of America.
This article was compiled from an interview by Matthew Peddie for "Florida Matters Live & Local." You can listen to the full episode here.
