According to one study conducted in India, patients are off the immunosuppressive drug cyclosporine three months after undergoing living donor kidney transplantation and an elaborate set of treatments that included a separate surgical procedure to infuse crushed donor kidney tissue into their thymus. In another study conducted at the University of Pittsburgh, a more simple strategy, but one just as bold, has some patients who received transplants of the small bowel, one of the must vulnerable organs to rejection, requiring just one anti-rejection pill once a week instead of the usual two or three pills two times a day. While in some patients the researchers had to back off when rejection occurred, they do plan to continue weaning the patients who so far are doing well, perhaps having them completely off the anti-rejection drug tacrolimus after one year.
The Pittsburgh team's encounters with rejection and the results of a third study from Stanford University are a reminder of the formidable challenge of achieving tolerance, defined as the permanent acceptance of the transplanted organ without immunosuppressive drugs. Two kidney transplant patients who were weaned off all drugs within a year of their transplants and who were drug-free for about five months have since experienced mild rejection necessitating their going back to low doses of drugs. But the rejection now treated, their doctors at Stanford are beginning to taper their drugs and are weaning a third patient in the study as well. At this point, the numbers are too small to draw conclusions about their results, they say.