Methods of diagnosing inflammatory bowel disease
View Patent ↗The present invention provides methods for diagnosing the presence or severity of inflammatory bowel disease (IBD) in an individual and methods for stratifying IBD by determining the level of one or more IBD markers in a sample from the individual and calculating an index value using an algorithm based upon the level of the IBD markers. Methods for monitoring the efficacy of IBD therapy, monitoring the progression or regression of IBD, and optimizing therapy in an individual having IBD are also provided.
1. A method for optimizing therapy in an individual having inflammatory bowel disease (IBD) and receiving a course of therapy for the treatment of IBD, said method comprising:
(a) obtaining a biological sample from said individual;
(b) measuring a concentration level of at least one marker selected from the group consisting of an anti-neutrophil cytoplasmic antibody (ANCA), anti- Saccharomyces cerevisiae immunoglobulin A (ASCA-IgA), anti- Saccharomyces cerevisiae immunoglobulin G (ASCA-IgG), an anti-outer membrane protein C (anti-OmpC) antibody, an anti-I2 antibody, and an anti-flagellin antibody in said sample obtained from said individual;
(c) applying a logistic regression algorithm to the measured concentration level of said at least one marker to calculate an index value for said individual;
(d) comparing the index value calculated from step (c) to an index value for said individual that was calculated at an earlier time during said course of therapy; and
(e) determining a subsequent dose of said course of therapy for said individual based upon said comparison from step (d), wherein a higher index value calculated from step (c) indicates a need to increase the subsequent dose of said course of therapy.
2. The method of claim 1 , wherein said course of therapy is selected from the group consisting of an aminosalicylate, a corticosteroid, a thiopurine, methotrexate, infliximab, and a combination thereof.
3. The method of claim 1 , wherein step (b) comprises measuring the concentration level of at least two of said markers.
4. The method of claim 1 , wherein step (b) comprises measuring the concentration level of at least three of said markers.
5. The method of claim 1 , wherein step (b) comprises measuring the concentration level of at least four of said markers.
6. The method of claim 1 , wherein step (b) comprises measuring the concentration level of at least five of said markers.
7. The method of claim 1 , wherein step (b) comprises measuring the concentration level of all six of said markers.
8. The method of claim 1 , wherein step (b) comprises measuring the concentration level of ANCA, ASCA-IgA, ASCA-IgG, and anti-OmpC antibody.
9. The method of claim 1 , wherein step (b) further comprises measuring a concentration level of at least one marker selected from the group consisting of elastase, lactoferrin, and calprotectin.
10. The method of claim 1 , wherein said logistic regression algorithm has the following formula:
Index Value=Exp( b 0 +b 1 *x 1 + . . . +b n *x n )/(1+Exp( b 0 +b 1 *x 1 + . . . +b n *x n )),
wherein
b 0 is an intercept value;
b 1 is the regression coefficient of the first marker;
x 1 is the concentration level of the first marker;
b n is the regression coefficient of the n th marker;
x n is the concentration level of the n th marker; and
n is an integer of from 1 to 6.
11. The method of claim 1 , wherein the concentration level of said marker is measured by assaying said sample with an enzyme-linked immunosorbent assay (ELISA).
12. The method of claim 1 , wherein the concentration level of ANCA is measured by assaying the binding between ANCA and fixed neutrophils.
13. The method of claim 1 , wherein the concentration level of ASCA-IgA or ASCA-IgG is measured by assaying the binding between ASCA-IgA or ASCA-IgG and an antigen selected from the group consisting of yeast cell wall mannan, a purified oligomannoside antigen, a synthetic oligomannoside antigen, and combinations thereof.
14. The method of claim 13 , wherein said antigen is yeast cell wall phosphopeptidomannan (PPM).
15. The method of claim 14 , wherein said yeast cell wall PPM is S. uvarum PPM.
16. The method of claim 1 , wherein the concentration level of anti-OmpC antibody is measured by assaying the binding between the anti-OmpC antibody and an OmpC protein or an immunoreactive fragment of said OmpC protein.
17. The method of claim 1 , wherein the concentration level of anti-I2 antibody is measured by assaying the binding between the anti-I2 antibody and an I2 protein or an immunoreactive fragment of said I2 protein.
18. The method of claim 1 , wherein the concentration level of anti-flagellin antibody is measured by assaying the binding between the anti-flagellin antibody and a flagellin protein or an immunoreactive fragment of said flagellin protein.
19. The method of claim 18 , wherein said flagellin protein is selected from the group consisting of flagellin X, flagellin A, flagellin B, Cbir-1 flagellin, immunoreactive fragments thereof, and combinations thereof.
20. The method of claim 1 , wherein said sample is a serum sample.
21. The method of claim 1 , wherein said IBD is selected from the group consisting of Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC).