Concentration of serum bile acids as an index of hepatic damage in systemic lupus erythematosus.

The aim of this work is to evaluate the concentration of serum bile acids (SBA) as an index of impaired liver function in systemic lupus erythematosus (SLE) patients versus usual laboratory tests of hepato-biliary system diseases. In patients with SLE the mean fasting SBA concentration was 9.6 +/- 1.4 mumol/L; in normal subjects the concentration was 2.9 +/- 0.6 mumol/L (P less than 0.01). In patients with SLE, mean gamma-glutamyl transpeptidase (GGTP) concentration was 31.5 +/- 5.9 mU/ml versus 10.05 +/- 1.1 mU/ml in controls (P less than 0.01). The bromsulphalein (BSP) excretion test, 45 minutes after injection, was 6.8 +/- 1% in SLE patients versus 2.8 +/- 0.4% in controls (P less than 0.02). No significant difference was found between these two groups of subjects with respect to leucine aminopeptidase (LAP), alkaline phosphatase (AlPh), glutamic-oxalacetic transaminase (SGOT), glutamic-pyruvic transaminase (SGPT), bilirubin serum rates. SBA rate was abnormal in 50% of the SLE patients; GGTP rate and the BSP excretion test were abnormal in 38% and 27% respectively. Our findings show the presence of an actual liver impairment in SLE patients, significantly demonstrated by fasting SBA concentration, GGTP rate and BSP excretion test. Other liver function tests are less useful in evaluating hepatic damage in SLE.