Researchers in the U.S. say they may have found a way to allow kidney patients to ditch the powerful immune suppressing drugs that they need to take for life to prevent organ rejection.

The key lies in borrowing some stem cells from the donor's bone marrow. The cells are then engineered to "trick" the immune system of the recipient into thinking the new organ is an original part of the body.

"Essentially, it tricks the donor and recipient's immune system to accept each other," study author Dr. Suzanne Ildstad, a professor of Transplantation Research from the University of Louisville, told CTV News.

Transplant recipients usually are forced to take multiple immune-suppressing pills for life to prevent their own immune systems from rejecting the new organ. Kidney recipient Susan McKenzie tells CTV she takes eight pills a day. The pills not only come with a host of toxic side effects that boost her risk of heart disease and cancer, they interfere with her daily life.

"The really difficult part of it is that your immune sysytem is suppressed so you catch everything that is going around," she says.

"Your susceptibility to illness and infection is a big problem and of course, if you do get ill or have an infection ,you do have a risk of your kidney rejecting."

This new approach uses a special mix of bone marrow cells including blood-producing stem cells, and another type of cell named "facilitating cells. They also filter out certain cells that can cause a life-threatening disorder named "graft-versus-host disease."

The transplant recipients must then undergo radiation and chemotherapy to suppress their own immune system and allow it to accept the donated stem cells.

So far, teams from Northwestern Medicine and University of Louisville have tested the treatment on eight kidney transplant recipients. Two and a half years later, five of the patients have now been taken off immune-suppressing medication, the researchers reported Wednesday in the journal Science Translational Medicine.

One of those who received the treatment is Robert Waddell, who underwent a kidney transplant almost three years ago. He no longer needs any anti-rejection medications.

"I am living proof of this miracle that has happened to me. Someone who gave me a kidney changed my world," he says.

In the eight patients studied, two were able to switch to a low dose of one anti-rejection drug. One patient needed a repeat transplant after developing an infection.

The researchers believe the technique they developed could be used in other organ transplants. They say that not only would their new technique save patients from taking a cocktail of pills every day, it would also save health care dollars.

Anti-rejection drugs cost about $20,000 a year. This treatment -- though initially costly -- could eliminate years of fees.

"If an upfront investment of $15,000-$20,000 would allow a patient to be drug-free for the life of the person, and prevent rejection, that would be a huge cost savings," says Ildstad.

"This really is a big accomplishment," said Dr. Jeff Zaltzman, the director of kidney transplants at St. Michael's Hospital.

He noted that researchers have only followed patients for less than three years.

"We don't know if people will be able to maintain their tolerance (to the new organ), but clearly the technology in terms of what they have been able to achieve has reached a new level," Zaltzman said.

"If this kind of technology becomes mainstay, then the success of transplantation, in terms of the ability of getting patients off anti-rejection drugs, would be tremendous."

The clinical trial is ongoing but the preliminary results were considered important enough to be published now.

Researchers are now planning a second clinical trial, which would offer similar treatment for subjects who have already undergone a kidney transplant.

McKenzie, meanwhile, is encouraged by the new research and its potential to improve her quality of life. "The medication is by far the worst part of having a transplant. So it would change everything, it would be amazing."

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip