Organ transplants have saved thousands of lives over the past 50 years. But to prevent rejection of transplanted organs, patients have to take toxic drugs for the rest of their lives.
Now, several new studies show that it's possible for some transplant patients to avoid these drugs and their side effects. The studies appear in this week's New England Journal of Medicine.
One of the first transplant patients who volunteered to stop taking anti-rejection drugs was Jennifer Serle.
Serle, 28, got her first kidney transplant at the age of 13. She then suffered drug side effects that ranged from weak bones and memory loss to viral warts that made her feet so painful she couldn't walk.
"I knew I had to do something drastic because I was young," she says. "To think of 20, 30, 40 years living like that, I didn't want any part of it.
So Serle entered a study at Massachusetts General Hospital in Boston. After years of experiments in animals, researchers were ready to see if they could dispense with immune-suppressing drugs and all their side effects.
To Serle's delight, it worked.
"So now it has been five years and I have not taken any medications that a normal transplant patient would take," she says.
Her bones have strengthened, she's mentally sharp — and the warts disappeared.
"I'm definitely walking," she says. "I actually ran two marathons in October. It's basically been the healthiest that I've ever been in my life."
New Transplant Method
Serle's story marks a turning point in getting patients to tolerate genetically different transplants. In her case, she got a kidney from her mother, who was only a partial match.
Dr. David Sachs of Massachusetts General Hospital says it was the first time drugs were stopped intentionally.
"We are delighted with the outcome," he says. The key for Serle was transplanting not just her mother's kidney but also a bit of her mother's bone marrow.
That gave Serle an immune system that was essentially a blend of her own and her mother's. Immune cells called T-cells, which normally attack anything foreign, are fooled into ignoring the transplanted kidney or at least tolerating it.
"You end up with T-cells that can react against everything else in the environment — bacteria, viruses, any other antigen — except recipient and donor [cells]," he says. "That's what we call tolerance."
The trick succeeded in three other patients. Other papers in the Journal detail two patients who achieved tolerance with other maneuvers. These patients also are doing without immune-suppressing drugs.
Doesn't Apply to All
That doesn't mean this approach works for all transplant patients. It's still experimental. Sachs says the treatment that his patients require before the transplant takes several days. That precludes taking organs from brain-dead donors. There's too little time.
"The only requirement right now is that it has to be from a living donor," Sachs says. "We haven't yet got this procedure working in a situation where it's a deceased donor, which is of course the usual case for many other transplants, such as the heart."
Others are skeptical of the new findings. Dr. Tom Starzl, a transplant pioneer at the University of Pittsburgh, doesn't see the Boston group's method as a breakthrough. He says the preparation that was used is "too complex" to be used clinically.
In Pittsburgh, Starzl says doctors are fine-tuning their transplant regimens to achieve partial tolerance by radically reducing — but not totally stopping — the number of doses and the number of drugs a person has to take.
"We see no real reason to go from one dose a week to nothing," he says.
The Boston group also has another big goal in mind. Sachs says achieving tolerance in mismatched human transplants is a step toward the day when animal organs might be safely put into people.