New warning signs may predict whether a kidney transplant will succeed--Mayo study.

Kidney transplants that show a combination of fibrosis and inflammation after one year are at higher risk of long-term failure, according to researchers at the Mayo Clinic, Rochester, MN. To identify the abnormalities, physicians would have to perform routine biopsies on apparently normal kidney transplants--rather than waiting for problems to occur.

"Even for some transplants that would be expected to have a very long graft survival, protocol biopsies performed in the first year may indicate the kidney is undergoing damaging inflammation, which is associated with increased risk for reduced function and graft survival," observed Mark Stegall, MD, Mayo Clinic transplant surgeon. The study will appear in an incoming issue of the Journal of the American Society of Nephrology (JASN).

The researchers analyzed factors related to transplant survival in 151 patients who had no apparent problems after living-donor kidney transplantation. One-year biopsies showed no abnormalities in 57% of kidneys; another 30% had fibrosis but no inflammation. In the two groups, the transplanted kidney continued to function normally from one to five years' follow-up. However, in the remaining 13% of transplants, biopsies showed fibrosis plus inflammation.

The transplants had declining kidney function and a reduced long-term survival rate. Kidneys showing fibrosis pus inflammation also had increased number of immune cells as well as a "rejection-like" gene expression signature. "It is likely that the intragraft environment of patients with fibrosis and inflammation is damaging to the allograft,' Stegall said. (09/17/10)