Serial quantitative liver function tests in patients with primary biliary cirrhosis: a prospective long-term study

Primary biliary cirrhosis (PBC) is a rare chronic cholestatic disorder of unknown origin that can now be treated effectively with ursodeoxycholic acid (UDCA). The clinical course of PBC is very variable, but a significant proportion of patients eventually die or undergo liver transplantation. In this single-center prospective long-term study, we analyzed the effect of UDCA therapy (10 mg/kg b.w./day) on conventional liver function tests and we also investigated whether serial quantitative liver function tests are useful in the clinical management of patients with PBC. Fifteen patients, most of them in an early disease stage, were followed up for either 4 (n = 7) or 5 (n = 8) years. In addition to regular conventional liver function tests, every 12 months quantitative liver function tests were performed. Thus we measured galactose elimination capacity, indocyanine green half-life and lidocaine half-life. Quantitative liver function tests were also performed once in healthy volunteers. Treatment with UDCA significantly improved conventional liver function tests, and this effect was maintained for several years (values in U/l before therapy and 4 years after therapy: AP = 1,346 +/- 317 vs. 516 +/- 93; gammaGT 378 +/- 80 vs. 144 +/- 30; LAP 122 +/- 10 vs. 71 +/- 9; AST 61 +/- 19 vs. 34 +/- 12; ALT 90 +/- 19 vs. 68 +/- 35; GLDH 14.3 +/- 1.9 vs. 8.2 +/- 1.9). Quantitative liver function tests were not significantly different between healthy volunteers and patients (GEC 6.8 +/- 0.3 vs. 7.0 +/- 0.3 mg/kg x min; ICG half-life 4.2 +/- 0.4 vs. 3.7 +/- 0.3 min; lidocaine half-life 75 +/- 8 vs. 79 +/- 6 min). In the patients, results of quantitative liver function tests (GEC, ICG and lidocaine half-lives) were not affected by UDCA therapy and remained constant over time. In the 1 patient who was transplanted, serial quantitative liver function tests did not indicate deteriorating liver function earlier than the patient's progressive symptoms or conventional liver function tests. Thus UDCA therapy markedly improved conventional liver function tests in patients with PBC, and this effect was maintained for at least 4-5 years. Possibly due to the fact that most of the patients were in an early disease stage, serial quantitative liver function tests provided little additional information that was relevant for planning therapy in the individual patient.