Alkaline phosphatase isoforms in serum after liver allograft surgery.

Orthotopic liver transplantation (OLT) is now the only available treatment for end-stage liver disease; the major postoperative complications of OLT are rejection and infection. Fractionation of alkaline phosphatase (ALP) isoforms in serum by isoelectric focusing can be used to identify patients with complications. Reference ranges for liver-function tests (LFT) and liver ALP isoforms were established for post-OLT patients with stable postoperative courses and compared with those of patients with complications. We found canalicular, hepatocyte, and high-molecular-mass ALP to be statistically higher in nearly all patients with complications as compared with patients who had a stable postoperative course; these tests may identify patients requiring a liver biopsy. When used in conjunction with LFT and other clinical findings, ALP isoforms could aid in the monitoring of complications and treatment and in the adjustment of immunosuppressive therapy in stable OLT cases.