Plasma amino acids in liver transplantation: correlation with clinical outcome.

The branch chain to aromatic amino acid ratio is depressed in patients with advanced liver disease. Liver transplantation results in three different ratio response patterns: (1) no improvement, (2) transient improvement followed by decline, and (3) sustained improvement. In nine patients who underwent 12 transplantation procedures the ratio rose and remained above 2.5 during 70.0% +/- 14.8% of the postoperative period in survivors compared with 11.8% +/- 3.1% when transplantation was unsuccessful (p less than 0.001). At discharge survivors' ratios had risen from 1.5 +/- 0.1 to 3.2 +/- 0.2 (p less than 0.001). The ratio before death or retransplantation caused by graft failure was unchanged at 1.2 +/- 0.1. A persistently low branch chain to aromatic amino acid ratio after liver transplantation should prompt an aggressive search for reversible causes of liver dysfunction. If the ratio does not respond to appropriate therapy, efforts should be directed toward retransplantation.