Alpha thalassemia major is, by any stretch of the imagination, a dreadful, heart breaker of a disease. It’s caused by four missing or mutated genes and it almost always leads to a fetus dying before delivery or shortly after birth. Treatments are limited and in the past many parents were told that all they can do is prepare for the worst.
Now, however, there is new hope with new approaches, including one supported by CIRM, helping keep these children alive and giving them a chance at a normal life.
Thalassemias are a group of blood disorders that affect the way the body makes hemoglobin, which helps in carrying oxygen throughout the body. In alpha thalassemia major it’s the lack of alpha globin, a key part of hemoglobin, that causes the problem. Current treatment requires in blood transfusions to the fetus while it is still in the womb, and monthly blood transfusions for life after delivery, or a bone marrow transplant if a suitable donor is identified.
A clinical trial run by University of California San Francisco’s Dr. Tippi MacKenzie – funded by CIRM – is using a slightly different approach. The team takes stem cells from the mother’s bone marrow and then infuses them into the fetus. If accepted by the baby’s bone marrow, these stem cells can then mature into healthy blood cells. The hope is that one day this method will enable children to be born with a healthy blood supply and not need regular transfusions.
Treating these babies, saving their lives, is the focus of a short film from UCSF called “Surviving with Joy”. It’s a testament to the power of medicine, and the courage and resilience of parents who never stopped looking for a way to help their child.
Dr. Tippi MacKenzie (left) of UCSF Benioff Children’s Hospital San Francisco, visits with newborn Elianna and parents Nichelle Obar and Chris Constantino. Photo by Noah Berger
Imagine being able to cure a genetic disorder before a baby is even born. Thanks to a CIRM funded study, what would have been a mere dream a couple of years ago has become a reality.
Drs. Tippi MacKenzie and Juan Gonzalez Velez of the University of California San Francisco (UCSF) have successfully treated alpha thalassemia in Elianna Constantino, using stem cells from her mother’s bone marrow. Alpha thalassemia is part of a group of blood disorders that impairs the body’s ability to produce hemoglobin, the molecule that is responsible for transporting oxygen throughout the body on red blood cells. Present in approximately 5% of the population, alpha thalassemia is particularly prevalent among individuals of Asian heritage. Treatment options for this disease are severely limited, generally requiring multiple rounds of blood transfusions or a bone marrow transplant which requires immunosuppressive therapy. Normally, fetuses die in the womb or the pregnancy is aborted because of the poor prognosis.
The revolutionary treatment pioneered at UCSF involved isolating blood stem cells (cells that are capable of turning into all blood cell types) from the mother’s bone marrow and injecting these cells into Elianna’s bloodstream via the umbilical vein. The doctors were able to observe the development of healthy blood cells in the baby’s blood stream, allowing for efficient oxygen transport throughout the baby’s body. Because the cells were transplanted at the fetal stage, a time when the immune system is not fully developed, there was low risk of rejection and the transplant occurred without aggressive immunosuppressive therapy.
The baby was born healthy earlier this year and has been allowed to return home. While it is still too early to tell how effective this treatment will be in the long term, it is very encouraging that both the mother and baby have endured the treatment thus far.
“Her healthy birth suggests that fetal therapy is a viable option to offer to families with this diagnosis.”
The in utero stem cell transplant was performed as part of a clinical trial conducted at the UCSF Benioff Children’s Hospitals in San Francisco and Oakland. The trial is currently enrolling 10 pregnant women to test the safety and effectiveness of this treatment over a wider population.
If successful, this type of treatment is particularly exciting because it could be expanded to other types of hereditary blood disorders such as sickle cell anemia and hemophilia.