An experimental treatment derived from a potentially deadly microorganism may provide lifesaving help for kidney transplant patients, according to an international study led by investigators at Cedars-Sinai.

The study, published in the New England Journal of Medicine, found that treating patients with the drug IdeS before transplantation significantly reduced, and in most cases eliminated, donor-specific antibodies that can cause rejection or failure of the new organ.

IdeS is derived from an enzyme in the bacteria Streptococcus pyogenes, which causes disorders ranging from sore throats to life-threatening infections.

Stanley C. Jordan, MD, medical director of the Kidney Transplant Program at Cedars-Sinai, said the enzyme is the only one that can completely remove organ-rejecting antibodies and allow kidney transplantation to take place.  One hour after infusion of the enzyme, antibodies declined drastically.

“We found that IdeS could immediately cut patient antibodies in half, making them powerless to attack and injure a newly transplanted kidney,” said Jordan, who received a consulting fee from Hansa Medical of Sweden, the company that produced the enzyme and funded the research. “We can put a new kidney in a patient without it being rejected.”

The study involved two coordinated investigations, with a total of 25 patients treated in the U.S. and Sweden. Twenty-four of the patients were transplanted successfully after receiving the investigational therapy.

“We need larger studies to confirm the promising results of this unique approach to removing patient antibodies that threaten newly transplanted organs,” Jordan said. “And we want to investigate any long-term impact IdeS therapy may have on overall antibody production in patients.”