Many patients in need of kidney transplants are sensitized to immune system proteins and antibodies because of previous transplants, blood transfusions or pregnancies. The Hopkins team used a blood filtering process called plasmapheresis, coupled with a drug that suppresses immune system antibodies to stop these patients from making antibodies that attack transplant organs and cause their rejection. After the new treatment, a majority of 34 patients treated at Hopkins since 1997 stopped producing antibodies against their donors' HLA antigens, the targets of rejection, and maintained that status for an average of 13 months post-transplant. Most organ rejection occurs during the first three months following surgery.
"I've been in this business 30 years and I've never seen anything like these results," says Andrea A. Zachary, Ph.D., lead author of the antibody study and associate professor of medicine at Hopkins. "If we can stop the production of antibodies against the donor organ permanently, better long-term survival of donated kidneys and patients would be likely."
She will present the study results Monday, Aug. 26, at 3:45 p.m. at The Transplantation Society's 19th International Congress in Miami.
Researchers followed the 34 patients transplanted, who had expressed antibodies against the donors' HLA antigens. Twenty-two were in for a first transplant and 12 for a repeat transplant. Ten of the kidneys came from cadavers, 14 from living blood relatives and 10 from other living donors.
At the end of the blood-filtering and medication treatments, 27 of 34 patients (79 percent) had lost antibodies against donor organs, and 15 of 30 (50 percent) patients who had antibodies against other HLA antigens had stopped producing those. Among 26 assessed an average of 13 months after treatment, 24 (92 percent) had no antibodies against their donors, while only three of 22 patients stopped making antibodies to other HLA antigens or to viruses. One patient died during treatment.
"The effect is very specific and should not have some of the long-term side effects of the routine transplant medications," Zachary says.
To interview Zachary, please contact me at 410-955-1534 or kblum@jhmi.edu. Please observe the meeting embargo of Monday, Aug. 26, at 3:45 p.m.
For more information on the Hopkins program, visit the following Web site: http://www.hopkinsmedicine.org/transplant