Drug Could Benefit Organ Transplant Patients

A recent study at the UCSD department of medicine’s division
of nephrology suggests that the drug sirolimus may help prolong the benefits of
transplanted kidneys and delay rejection, especially for “noncompliant”
patients who do not regularly take their prescribed medications.

Cheri Ye, M.D., presented the findings at the 2008 American
Transplant Congress in Toronto on
May 31.

Ye’s mentor, professor of medicine and director of
transplant nephrology Robert Steiner, said the drug — whose brand name is
Rapamune — may be the answer to undetectable complications associated with
kidney transplants.

“No one is perfect at taking medications,” he said. “But
missing doses of immunosuppression, or not taking full doses each day, will
bring about gradual rejection of kidney transplants that is almost impossible
to detect in its early stages. Long-acting drugs like sirolimus may help with
this problem.”

A team of five UCSD investigators assessed immune function
at “trough” levels (lowest daily intake) of the three most commonly prescribed
immunosuppressive drugs, measuring “mitogenic response” and the level of
protection from rejection in 160 kidney-transplant patients.

At these trough levels, sirolimus caused a significantly
lower level of mitogenic response — representing greater protection — and
results were stable in patients over time.

“At least half of transplanted kidneys are lost through
chronic graft rejection, usually within 10 years,” said David Perkins, professor
of medicine and surgery and director of research for transplantation. “When
patients do not have those rejection problems, they can go for 20 to 30 years
before kidney rejection or other serious problems. This is an especially
important issue now because of our nationwide donor-organ shortage.”