Markers Predict Outcome of Liver Transplant

A new study has found that measuring serum sodium in potential liver transplant patients is better able to predict those with a poor prognosis than the three markers previously used.

Since 2002, liver allocation in the United States has been based on a patient's score on the MELD (model for end-stage liver disease), which uses levels of three biochemical markers to predict three-month mortality in patients with cirrhosis of the liver listed for transplantation. Those three markers are serum bilirubin, serum creatinine, and prothrombin time. The current study was intended to show if adding serum sodium and hyponatremia (low sodium level in the blood) would increase the accuracy of the MELD score to predict the risk of death on the waiting list.

Led by Andres E. Ruf, M.D., of the Liver Unit of the Fundacion Favaloro in Buenos Aires (Argentina), the study included 262 patients with cirrhosis who were listed for liver transplantation between June 1995 and January 2003. Serum bilirubin, creatinine, and sodium were measured at the time of listing and used to calculate a MELD score. The efficacy of serum sodium, hyponatremia, and MELD to predict death within three and six months of listing was analyzed with two different statistical methods. Results of the study showed that when added to the MELD, serum sodium and hyponatremia significantly increased the accuracy of the score in predicting short-term mortality.

"In our study, the prevalence of hyponatremia was significantly higher in patients who died within 3 months (63%) than in those who survived 3 months (13%),” the authors noted. "Similarly, patients with hyponatremia had significantly more advanced liver failure compared to those with normal serum sodium.” They add that although hyponatremia ultimately reflects renal impairment, it appears to be a more accurate and early marker of poor outcome than serum creatinine in transplant candidates with advanced cirrhosis.

The results of this study appear in the March 2005 issue of Liver Transplantation, published by John Wiley & Sons, Inc. and is available online via Wiley InterScience.