Process for in vitro diagnosis of hepatic disorders

1. A method of determining the presence and/or concentration of a protein ADH1B (SEQ ID NO: 2) or a combination of proteins ADH1A (SEQ ID NO: 1) and ADH1B (SEQ ID NO: 2) in a subject, comprising:

obtaining a blood sample from the subject; and

determining the presence and/or concentration of said protein(s) in the sample using one or more signature peptides comprising a signature peptide of SEQ ID NO: 17 for the protein ADH1B and a signature peptide of SEQ ID NO: 15 or SEQ ID NO: 16 for the combination of proteins ADH1A and ADH1B.

2. The method according to claim 1 , which further comprises determining the presence and/or concentration of one or more additional proteins selected from the group consisting of: ADH4 (SEQ ID NO: 3, SEQ ID NO: 4), BHMT1 (SEQ ID NO: 5), BHMT2 (SEQ ID NO: 6, SEQ ID NO: 7), ARG1 (SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10), FABP1 (SEQ ID NO: 11), GSTA1 (SEQ ID NO: 12) and ALT1 (SEQ ID NO: 13).

3. The method according to claim 1 , which further comprises determining the presence and/or concentration of one or more additional proteins selected from the group consisting of: ADH4 (SEQ ID NO: 3, SEQ ID NO: 4), BHMT1 (SEQ ID NO: 5) and BHMT2 (SEQ ID NO: 6, SEQ ID NO: 7).

4. The method according to claim 1 , which comprises determining the presence and/or concentration of the protein ADH1B or the combination of the proteins ADH1B and ADH1A; the protein ADH4 (SEQ ID NO: 3, SEQ ID NO: 4); and the protein BHMT1 (SEQ ID NO: 5) and/or BHMT2 (SEQ ID NO: 6, SEQ ID NO: 7).

5. The method according to claim 2 , which comprises the determination of the protein BHMT1 (SEQ ID NO: 5), the protein BHMT2 (SEQ ID NO: 6 and SEQ ID NO: 7) or both said proteins.

6. The method according to claim 1 , which further comprises determining the presence and/or concentration of the protein CK18.

7. The method according to claim 1 , wherein said signature peptide is generated from said protein by an enzymatic digestion process.

8. The method according to claim 2 , wherein the presence and/or concentration of said additional proteins is determined using one or more signature peptides selected from the group consisting of:

SEQ ID NO: 20, SEQ ID NO: 18 and SEQ ID NO: 19 for the protein ADH4;

SEQ ID NO: 25, SEQ ID NO: 24 and SEQ ID NO: 26 for the protein ARG1;

SEQ ID NO: 21, SEQ ID NO: 23 and SEQ ID NO: 22 for the protein BHMT;

SEQ ID NO: 21 for the protein BHMT1;

SEQ ID NO: 23 and SEQ ID NO: 22 for the combination of proteins BHMT1 and BHMT2,

SEQ ID NO: 27, SEQ ID NO: 28 and SEQ ID NO: 29 for the protein FABP1;

SEQ ID NO: 30 for the protein GSTA1; and

SEQ ID NO: 34, SEQ ID NO: 35 and SEQ ID NO: 36 for the ALT1 protein.

9. The method according to claim 2 , wherein the presence and/or concentration of ALT1 protein is determined using the signature peptide SEQ ID NO: 34 or SEQ ID NO: 35.

10. The method according to claim 1 , wherein the subject has or is suspected of having a liver disorder chosen from acute liver injury, hepatic steatosis and steatohepatitis.

11. The method according to claim 1 , wherein the subject has or is suspected of having a non-alcoholic steatohepatitis.

12. The method according to claim 1 , wherein the subject has been previously administered potentially toxic molecules.

13. A method of determining the presence and/or concentration of a protein ADH1B (SEQ ID NO: 2) or a combination of proteins ADH1A (SEQ ID NO: 1) and ADH1B (SEQ ID NO: 2) in a subject, using at least one signature peptide characteristic of the selected protein(s), comprising the steps:

(a) obtaining a blood sample taken from a subject at the time t 0 ,

(b) adding a known quantity of an isotopically labelled protein homologous to the selected protein(s), in the blood sample obtained in step a),

(c) treating the sample to extract at least a portion of the abundant proteins or at least a portion of the glycoproteins,

(d) treating the sample after extracting at least a portion of the abundant proteins or glycoproteins to generate proteolytic peptides including the signature peptides of said selected protein(s),

(e) quantitative assay by mass spectrometry of at least one signature peptide generated from the selected protein(s),

(f) determining a ratio of the abundance of the isotopically labelled signature peptide, from the standard, added in step b), to the abundance of the non-labelled signature peptide from the blood sample, and

(g) computing the concentration of said selected protein(s) in the sample based on the ratio obtained in step f) and on the known quantity of said isotopically labelled protein added in step b).

14. The method according to claim 13 , wherein step (c) is performed by glycodepletion.

15. The method according to claim 13 , wherein the method is performed at a time t 0 and at a time t 1 greater than t 0 , and comprises after step (g) the comparison of the concentration of the selected protein(s) in the sample between t 1 and t 0 .

16. The method according to claim 13 , wherein step (d) is performed by enzymatic digestion using trypsin or a mixture of EndolysC and trypsin.

17. The method according to claim 13 , wherein the subject has or is suspected of having a liver disorder chosen from acute liver injury, hepatic steatosis and steatohepatitis.

18. The method according to claim 13 , wherein the subject has or is suspected of having a non-liver steatohepatitis.

19. The method according to claim 13 , wherein the subject has been previously administered potentially toxic molecules.

20. The method according to claim 1 , wherein the blood sample is selected from the group consisting of blood, plasma and serum.

21. The method according to claim 13 , wherein the blood sample is selected from the group consisting of blood, plasma and serum.