News
Antibody Reduces Rejection in High-risk Kidney Transplants
Nearly 70 percent of kidney transplant patients get short-term drug therapy initially administered during surgery to help prevent rejection. In the first head-to-head comparison of the two drugs most commonly given to ward off acute kidney rejection, an international study led by researchers at Washington University School of Medicine in St. Louis shows that one - anti-thymocyte globulin - is superior. The results also suggest the drug could potentially save millions of dollars in health care costs by preventing the all-out immune attacks that can eventually lead to kidney rejection.
The study, published in the Nov. 9 issue of the New England Journal of Medicine, included only patients who were at high risk for acute rejection and for delays in graft function, in part because their kidneys came from cadaver donors. One year after transplant, patients who received anti-thymocyte globulin (Thymoglobulin®) had a significantly lower incidence of acute rejection, 15.6 percent, compared to 25.5 percent of patients receiving basiliximab (Simulect®). Anti-thymocyte globulin was even more effective at preventing episodes of acute rejection that require additional antibody therapy to stem the immune assault. Only 1.4 percent of patients who received anti-thymocyte globulin experienced such acute rejection versus 8 percent who got basiliximab.
"Acute rejection is a major risk factor for eventually losing a kidney," says Daniel C. Brennan, M.D., professor of medicine and director of transplant nephrology at Washington University School of Medicine. "Our study shows that anti-thymocyte globulin is an important weapon for fighting kidney rejection. A 10 percent difference in acute rejection between the two groups may not seem like a lot, but in these high-risk patients, it is very significant."
The study involved 278 patients in the United States and Europe who were randomly assigned to receive either anti-thymocyte globulin or basiliximab. This short-term induction therapy is commonly given during kidney transplant surgery and in the first several days afterward to prevent acute rejection prior to the start of more potent, long-term immunosuppressive therapy.
The study found no significant difference between the drugs in terms of delayed graft function, defined as the kidney's inability to make urine within the first week following transplant surgery. About 40 percent of patients in both groups experienced a delay in graft function. Brennan attributes this to the extended period of time the kidneys were kept on ice before transplant surgery, an average of 25 hours for patients in the anti-thymocyte group and 28 hours for the basiliximab group.
"The longer a kidney is kept cold outside of the body, the higher the risk of delayed graft function," Brennan says. "There is only so much a drug can do to overcome an extended 'cold time.' However, if the delay in graft function does not lead to acute rejection, usually there is no long-term effect on the kidney."