Scientists have developed a procedure which may help end the need for transplant patients to rely on powerful anti-rejection drugs.
The complex procedure involves mixing the patient's infection-fighting white blood cells with cells from the donor.
One patient went eight months without immunosuppressive drugs and others were switched to low doses.
The new technique involves giving transplant patients an infusion of specialised cells known as a transplant acceptance-inducing cells (TAICs).
The TAICs are created by isolating a type of white blood cell from the donor, and modifying them chemically in the lab.
Once modified, the cells gain the ability to kill off cells in the immune system which trigger the rejection process, and to boost the action of another type of immune cell which plays a beneficial role in guarding against rejection.
The cells are then cultured alongside those from the recipient - which helps prime the immune system further - before being injected into the patient.
The technique has been tested on kidney transplant patients, some of whom were given the cells before surgery, and others after the transplant, as an additional drug therapy.