ORLANDO, Fla.—Black renal transplant recipients receiving immunosuppression with rapamycin live longer than whites receiving the same drug, a study found.
Researchers at the University of Texas Medical School in Houston led by Bhamidipati V. R. Murthy, MD, reviewed ethnic differences in mortality among 380 first renal allograft recipients who received primary immunosuppression with rapamycin. The study population was 44% white, 29% black, and 26% Hispanic. Subjects received their transplants between 1993 and 2003. Investigators followed up with patients until March 2009. During follow-up, 106 patients (28%) died.
Compared with whites, blacks had a higher prevalence of hypertension, a longer time on dialysis prior to transplantation, a higher incidence of humoral rejections and graft loss, and a higher body mass index. Still, after adjusting for potential confounders, blacks were 46% less likely to die over the next nine or 10 years than whites, the researchers reported here at the National Kidney Foundation’s 2010 Spring Clinical Meetings. Hispanics had a 39% decreased risk compared with whites, but the difference between the groups was not significant.
“In selected minorities, particularly in African Americans, there may be a group who benefits from rapamycin,” Dr. Murthy said.In addition, men were 73% more likely to die than women. Each one-year increment in age was associated with a 5% increased risk of death. Patients with diabetic end-stage renal disease (ESRD) were 3.8 times more likely to die as those with ESRD resulting from other causes.
Rapamycin is less toxic to the kidneys than other immunosuppressive agents, so it may be better for long-term kidney function, Dr. Murthy noted. One disadvantage, he added, is that rapamycin can promote high cholesterol levels and high triglycerides; if this occurs, patients can be switched to another immunosuppressant.