HIGH-LEVELS OF (24S)-24-HYDROXYCHOLESTEROL 3-SULFATE, 24-GLUCURONIDE IN THE SERUM AND URINE OF CHILDREN WITH SEVERE CHOLESTATIC LIVER-DISEASE

Extracts of urine and serum from children with cholestatic liver disea se were analyzed by fast atom bombardment (FAB) mass spectrometry. Abo ut half of all spectra showed a peak at m/z 657, compatible with the p resence of a glucuronidated cholestenediol sulfate. Separation by ion exchange chromatography before and after solvolysis and treatment with beta-glucuronidase, combined with analyses by gas chromatography-mass spectrometry and FAB mass spectrometry with collision-induced dissoci ation, showed that the major compound responsible for the peak at m/z 657 was (24S)-24-hydroxycholesterol 3-sulfate, 24-glucuronide. The dou ble conjugate of 27-hydroxycholesterol was also identified and double conjugates of cholestene- and cholestanetriols were also present. Semi quantitative analyses of the double conjugate of 24-hydroxycholesterol in patients whose FAB spectra showed a peak at m/z 657 indicated seru m levels of 2-18 mu M and a daily urinary excretion of 0.1-2.7 mu mol/ 24 h. Eleven of 13 studied patients with a prominent peak at m/z 657 i n the FAB spectra of their serum or urine either underwent liver trans plantation or died. It is concluded that double conjugation of hydroxy sterols with sulfuric and glucuronic acids can be an important metabol ic pathway particularly for (24S)-24-hydroxycholesterol. It is specula ted that serious cholestatic liver disease may induce an increased for mation and release of (24S)-24-hydroxycholesterol from brain (Lutjohan n et al. 1996. Proc. Natl. Acad. Sci. USA. 93: 9799-9804) with subsequ ent extracerebral conjugation with sulfuric and glucuronic acids.