Mass spectrometry assay method for detection and quantitation of liver function metabolites

1. A method for determining in a sample, by mass spectrometry, the amount of three or more analytes selected from the group consisting of 12,13-DiHOME, 3-hydroxybutyrate (BHBA), 3-hydroxyoctanoate, 3-methylglutarylcarnitine, 3-ureidopropionate, 7-alpha-hydroxy-4-cholesten-3-one (7-Hoca), citrate, fucose, fumarate, gamma-tocopherol, glutamate, glutarate, glycerol, glycochenodeoxycholate, glycocholate, hypoxanthine, maleate, malonate, mannose, orotate, 2,3-pyrdinedicarboxylate, ribose, serine, taurine, taurochenodeoxycholate, taurocholate, palmitoleate, linolenate, xanthine, xylitol, and combinations thereof, the method comprising:

a) subjecting the sample to an ionization source under conditions suitable to produce one or more ions detectable by mass spectrometry from each of the three or more of the analytes, wherein the analytes are not derivatized prior to ionization;

b) measuring, by mass spectrometry, the amount of the one or more ions from each of the three or more analytes; and

c) using the measured amount of the one or more ions to determine the amount of each of the three or more analytes in the sample.

2. The method of claim 1 , wherein the three or more analytes are selected from the group consisting of 12,13-DiHOME, 3-hydroxyoctanoic acid, Citric Acid, Fucose, Glycerol, Glycochenodeoxycholate, Glycocholate, Malonic Acid, Palmitoleic Acid, Serine, Taurine, Taurochenodeoxycholate, Taurocholate, Xanthine, Xylitol, and Linolenic acid and wherein the amount(s) of the three or more analytes are determined in a single injection.

3. The method of claim 1 , wherein the three or more analytes are selected from the group consisting of 12,13-DiHOME, 3-Methylglutaryl L-carnitine, 7-alpha-hydroxy-4-cholesten-3-one (7-Hoca), Gamma-Tocopherol, Glutamic acid, Glycochenodeoxycholate, Glycocholate, Hypoxanthine, Serine, and Taurocholate and wherein the amount(s) of the three or more analytes are determined in a single injection.

4. The method of claim 3 , wherein the ionization source is operated in positive ionization mode.

5. The method of claim 1 , wherein the three or more analytes are selected from the group consisting of 2,3-pyridinedicarboxylic acid, 3-hydroxybutyrate, Fucose, Fumaric acid, Glutamic acid, Glutarate, Glycerol, Hypoxanthine, Maleic acid, Malonic Acid, Mannose, Orotate, Ribose, Serine, Taurine, 3-ureidopropionic acid, Xanthine, and Xylitol and wherein the amount(s) of the three or more analytes are determined in a single injection.

6. The method of claim 1 , wherein the ionization source is operated in negative ionization mode.

7. The method of claim 1 , wherein the one or more ions used to determine the amount of each of the three or more analytes are one or more ions selected from the ions in Tables 2, 3, and 4.

8. The method of claim 1 , wherein the sample has been purified by liquid chromatography prior to being subjected to an ionization source.

9. The method of claim 8 , wherein said liquid chromatography is selected from the group consisting of high performance liquid chromatography, ultra high performance liquid chromatography, and turbulent flow liquid chromatography.

10. The method of any of claim 1 , wherein an internal standard is used to determine the amount of the one or more analytes in the sample.

11. The method of claim 1 , wherein the mass spectrometry is tandem mass spectrometry.

12. The method of claim 1 , further comprising analyzing the sample using other methods useful in the clinical determination of liver function.

13. The method of claim 12 , wherein the other methods are selected from the group consisting of total cholesterol, total triglycerides, albumin, albumin/globulin ratio, total protein, direct bilirubin, total bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and serum cholinesterase (ChE).