LOS ANGELES – Cases of severe, therapy-resistant asthma are on the rise worldwide, and new strategies are needed to treat the estimated 100,000 people who die of asthma every year. Researchers from the National Institutes of Health and their colleagues are exploring a radical solution: bone marrow transplants.
Scientists know the transplants have the potential to reset the immune system and calm an overactive inflammatory response. They are already used to treat patients who develop acute graft-versus-host disease following an organ transplant. Asthma also involves excessive inflammation, prompting the airways to constrict and the lungs to secrete mucus. Why not reboot the immune systems with a bone marrow transplant?
To test their theory, the researchers gave the transplants to asthmatic mice that were allergic to ragweed. Then, when the mice were again exposed to ragweed, their allergic and asthmatic symptoms (measured by chemical levels in their blood) decreased significantly. The scientists concluded that the bone marrow transplants helped the mice by restoring a healthy balance of immune system cells known as Th1 and Th2.
The results were published online this week in Proceedings of the National Academy of Sciences.
Dr. Eva Mezey, who heads the adult stem cell research section at the National Institute of Dental and Craniofacial Research in Bethesda, Md., told HealthDay that “it’s very likely that the intervention would work in humans.”
But she emphasized that more research is needed before bone marrow transplants could be tested in people with severe asthma. For instance, although the mice got their bone marrow through an intravenous injection, human patients might do better with an aerosol because it could deliver the cells directly to the lungs, she said.