May 6 (HealthDay News) -- Few patients who have short-term kidney dysfunction while awaiting a liver transplant develop severe kidney problems once they have their transplant, says a U.S. study.

An increasing number of patients have kidney dysfunction while awaiting liver transplantation, which has led to debate among transplant experts about which patients are likely to develop kidney dysfunction after liver transplant and should be considered for combined liver/kidney transplantation.

This kind of decision is extremely difficult due to the lack of a reliable predictive model and the increasing shortage of organs available for transplant, according to background information in the study, led by Ranjeeta Bahirwani, of the University of Pennsylvania.

The study included 60 people who had liver transplants between March 2000 and August 2005, and had serum creatinine of at least 1.5 mg/dl for at least two weeks prior to, and at the time of, transplantation.

The patients were followed for a median of 36 months after their transplant, and only eight of them had significant kidney dysfunction. Those who had kidney dysfunction for more than 12 weeks before transplant were at increased risk for severe post-transplant kidney problems.

Diabetes and serum creatinine level at the time of transplant were other major predictors of severe post-transplant kidney problems.

"Our data are reassuring that the vast majority of patients with pre-transplant renal insufficiency do not develop advanced stage 4 or 5 chronic kidney disease," after liver transplant, the study authors wrote.

Serious post-transplant kidney disease was particularly rare among patients whose pre-transplant serum creatinine was elevated for less than 12 weeks. The researchers suggested that elevated serum creatinine levels for more than 12 weeks before transplant, the presence of diabetes, and the serum creatinine value at the time of transplant could help identify patients who might be considered for combined liver-kidney transplantation.

The study was published in the May issue of Liver Transplantation.

SOURCE: Liver Transplantation, news release, April 30, 2008