Doctors appear to have found a way for some organ transplant recipients to avoid lifelong immune-suppressing drugs. In new research this week, they detail how three children with a rare genetic condition were given a dual bone marrow and kidney transplant in hopes of completely avoiding immune rejection. And up to three years later, the young patients and their new kidneys are doing just fine.
Organ transplants are a life-saving operation for tens of thousands of Americans annually, but they come with drawbacks. Most notably, the body’s immune system is trained to eliminate cells that don’t resemble their host, including those belonging to a donated organ. As a result, patients have to undergo a lifelong course of drugs to suppress their immunity well enough to keep the organs from being rejected. These drugs carry many side-effects, including a higher risk of infections. And often, the donated organ wears out after a decade or so, largely because the immune system does still damage it over time.
Scientists have long tried to find a permanent solution to organ rejection, with limited success so far. But a team of researchers at Stanford Medicine now believe that they may have worked out such an approach, at least for certain patients.
Their patients were born with a rare hereditary condition called Schimke immuno-osseous dysplasia (SCOD). This condition can cause a variety of health problems, including dwarfism, kidney failure, and a weakened immune system. But the researchers theorised that the children’s weakened immune system also made it possible for them to effectively reprogram it to no longer treat donated cells as hostile.
To do this, they transplanted bone marrow — which contains stem cells that are the building blocks of our immune cells — along with a kidney from the same donor. Prior to the operation, the recipients were also given immune-suppressing therapy, and the donated organs were treated to get rid of immune cells that might attack the host body. Afterward, they were carefully monitored for signs of immune rejection.
The procedure appeared to work in all three patients. None experienced acute rejection. And 22 to 34 months later, they all seemed to have normal kidney and immune function without the need for anti-rejection drugs. The team’s findings were published Wednesday in the New England Journal of Medicine.
While remarkable, the results are obviously based on a very small sample size. Earlier attempts to use a similar dual transplant technique on SCOD patients hadn’t been successful, according to NBC News, though the researchers say these failures helped them learn how to improve their method. The children’s other SCOD-related symptoms will also continue to need management, and it will take time to know whether their new kidneys will indeed last longer than usual.
Still, this is the latest research to suggest that it’s possible to permanently tame the immune system following organ transplantation. Researchers at Duke University earlier this year performed a similar dual transplant on a baby boy with a weakened immune system who needed a new heart, and early data suggests that his body has fully accepted the donated organ.
Perhaps the most important question is whether these dual transplants will one day allow doctors to retrain people’s immune systems in general, not just in patients with these specific conditions. But for now, the lives of these children are expected to be far brighter than before.