"A new treatment might open the door for more patients with advanced kidney disease to get a transplant a preliminary study suggests. Of the plus Americans waiting for a donor kidney about onethird are sensitized said Dr. Robert Montgomery director of the Transplant Institute at NYU Langone in New York City. Those patients face a tough situation They harbor immune system antibodies that are primed to attack a donor organ. The antibodies can form when a person is exposed to foreign tissue Montgomery explained. So a patient whos had a prior kidney transplant may be highly sensitized  meaning they have a large number of the offending antibodies. It can also happen to patients whove had blood transfusion or ever been pregnant Montgomery said. Its almost impossible to find a compatible donor for those patients. But they might be able to receive a kidney from an incompatible donor if they first undergo an extensive desensitization process. That involves various treatments  including IV drugs called immune globulin and rituximab  that try to quash the antibodies that would attack the donor organ. Now the new research suggests a simple approach  an infusion of a particular enzyme hours before the transplant  could offer a better alternative. Researchers found that the treatment  dubbed IdeS  quickly wiped out the dangerous antibodies allowing all but one of  patients to have a successful transplant. The findings were published in the Aug.  issue of the New England Journal of Medicine. Funding for the study came from the company developing IdeS  Hansa Medical. Montgomery who was not involved in the study said hes never seen anything like it. When you give this all of the antibodies are gone Montgomery said. Im hopeful that this will turn out to be a gamechanger. However he stressed many questions remain. Critically the enzyme does not banish the antibodies forever. They come back Montgomery said  and the results of that comeback vary from patient to patient. In the study  patients had an episode of antibodymediated rejection anywhere from two weeks to five months after their transplant. That means antibodies started to attack the new kidney. Those patients were all successfully treated with standard antirejection drugs according to the researchers. Still its not yet clear how the patients will fare in the long term said Dr. Julie Ingelfinger a professor at Harvard Medical School in Boston. Ingelfinger who wrote an editorial published with the study echoed Montgomerys cautious optimism. If larger longer studies bolster the current findings she said this could potentially be practicechanging. But Ingelfinger stressed only time will tell. Lead researcher Dr. Stanley Jordan agreed that more work is necessary. But the findings mark another step forward for patients like these according to Jordan who is medical director of the kidney transplant program at CedarsSinai in Los Angeles. Traditionally highly sensitized patients in need of a kidney have languished on waiting lists because its so hard to find a compatible donor. But in the past  years or so desensitization has emerged as an alternative. Last year a landmark study proved that patients who receive transplants after desensitization live significantly longer than those who stay on dialysis. The outcomes have been good Jordan said. But he added theres clearly room for improvement. Ingelfinger agreed. The desensitization protocols now in use are timeconsuming and they dont always work she said noting that they can leave dangerous antibodies behind. Desensitization adds about  to  to the cost of the transplant according to the University of Wisconsins transplant center. The new approach is quite different Ingelfinger said. Patients receive one infusion of an enzyme called IdeS four to six hours before the transplant. The enzyme is derived from a strain of Streptococcus bacteria and it essentially chops up the antibodies that would attack the organ. Jordan acknowledged that the source sounds scary but stressed that patients do not receive the bacteria itself  but an engineered version of the enzyme. In all  U.S. and Swedish patients received an infusion of IdeS before their kidney transplant. All but one had a successful transplant and none had detectable antibodies immediately afterward. IdeS patients still received additional treatment  including a week of immune globulin and rituximab infusions. And as with all transplants they needed standard antirejection drugs. Because IdeS so readily banishes the offending antibodies it might make transplants feasible for even the most highly sensitized patients Montgomery said. But the  question remains he said Can it extend the survival of the donor kidney and ultimately patients lives IdeS is still experimental and the only way patients could receive it is through a clinical trial. It will be a few years before it could be more widely available Montgomery said. More information The National Kidney Foundation has more on kidney transplantation. https SOURCES Stanley Jordan M.D. medical director kidney transplant program CedarsSinai Medical Center Los Angeles Robert Montgomery M.D. director Transplant Institute and professor transplant surgery NYU Langone Medical Center New York City Julie R. Ingelfinger M.D. professor pediatrics Harvard Medical School Boston and deputy editor New England Journal of Medicine Aug.   New England Journal of Medicine"