Tuesday, August 24, 1999 Published at 21:56 GMT 22:56 UK
Immune breakthrough aids transplantation
"Mixed chimerism" could help more people have transplants
Receiving a transplant organ also means a lifetime of drugs to prevent the body rejecting it - until now, say US scientists.
For the first time, doctors have managed to get the body of a transplant patient to tolerate its donor kidney without the aid of medication to suppress the immune system.
And it may mean that less-perfect matches between donors and their organs can be used in future.
The technique used is called "mixed chimerism", which, although used before to allow the use of imperfectly matched bone marrow transplants in frail cancer patients, has never been successfully used in the field of organ transplantation.
It involves blending the immune systems of the donor and host to fool the body into accepting the foreign tissue.
The breakthrough case, reported in the journal Transplantation, involved a woman who had developed kidney failure as a result of a cancer called multiple myeloma.
She needed both a bone marrow and kidney transplant from her sister.
Too weak to cope
However, the damage to the kidneys meant she was too weak to withstand the usual preparation for the operations, which involves destroying the existing bone marrow with toxic chemotherapy or radiation.
And the new kidney is still working well, they reported.
Dr Benedict Cosimi, head of the transplantation unit at Massachusetts General Hospital, said: "This is the first step towards the day when transplant recipients can be made tolerant to their donors' organs without the risks and costs of lifelong immunosuppressive drugs."
He said it opened the door for transplants from less closely-matched donors, potentially meaning many more people could benefit from lifesaving surgery.
Dr Thomas Spitzer, also from Massachusetts General Hospital, said: "The great results we've seen with this patient, who probably would not have survived without these transplants - raises the possibility that other patients with blood-cell cancers and kidney failure may be successfully treated."