1. Biomarkers Managing IBD
Stephen B. Hanauer, MD
University of Chicago

2. Traditional Clinical Parameters:
Genetic markers
Serum immune markers
Cytokine profile
Enzyme activity
Metabolite levels
Genetic, Serologic, and Biochemical Profiles: + 1 2 3
Crohn’s Diseases
and
Ulcerative Colitides CD UC
Figure 1
CD/UC
IBD subtype: 1 4 2 3 4 1 3 2

3. Role of Biomarkers in IBD
Disease Classification
Disease Activity
Prognosis

4. Names based on mechanisms
Defining IBD CD UC
20th Century
Classic names
IBD1
IBD2
IBD3
IBD4
Severe Disease
Mild Disease
21st Century
Names based on mechanisms
Abreu MT, et al. Clin Perspect Gastroenterol. May/June 2001;

5. pANCA ASCA OMPc Anti-I2 CBir1
IBD Serologies
pANCA
ASCA
OMPc
Anti-I2
CBir1

6. Differential Diagnosis: Serological Markers
100 80 60 40 20
ASCA Specific for CD
Anti-saccharomyces cervisiae antibody (ASCA)
Perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA)
ANCA Sensitive
For Colitis
% Patients with Positive ASCA
and ANCA Test Results
CD UC Miscellaneous Controls (n=100) (n=101) non-IBD (n=163) (n=28)
Quinton J-F et al. Gut. 1998;42:788.

7. Accuracy of ANCA and ASCA to Differentiate UC from CD
Sensitivity
Specificity
PPV
100 97 95 94 91 91 88 80 78 69 60 60
Percentage (%) 56 50 40 44 20
ASCA+
(CD)
pANCA+
(UC)
ASCA+/pANCA-
(CD)
pANCA+/ASCA-
(UC)
Peeters M, et al. Am J Gastroenterol. 2001;96:

8. The Value of Serologic Markers in Indeterminate Colitis (IC)
Study Design:
97 patients with IC from 3 centers analyzed for pANCA and ASCA
Patients prospectively analyzed since 1996
Follow-up time from inclusion  1 year for each patient
Mean disease duration at time of publication, 10.7 years
Marker
Diagnosis
Sensitivity
Specificity
PPV
NPV
ASCA+/ pANCA– CD
67%
78%
80%
64%
ASCA–/ pANCA+ UC
Joossens S, et al. Gastroenterology. 2002;122:

9. The Value of Serologic Markers in IC
pANCA+/ASCA–
ASCA+/ pANCA–
Standard Markers
70% UC
67% CD
PPV
Diagnosis
83%
75%
PPV
pANCA+/ ASCA-/ OmpC- /I2-
OmpC
New Markers
72% remain IC
Joossens SB, et al. Gastroenterology. 2003;124(suppl1):A-323. Abstract M1174.

10. Summary of pANCA/ASCA pANCA is sensitive for “colitis”
Does not differentiate UC from CD
High titers associated with risk of pouchitis
ASCA is specific for “classic” (small bowel) Crohn’s
Rarely positive in indeterminate colitis without small bowel disease

11. IBD Specific Serologic Immune Markers
Antibody
Antigen
Non-IBD (%)
CD (%)
UC (%)
DNase Sensitive pANCA
Histone H1, bacterial antigen?
<5%
10–25%
50–65%
ASCA
Anti-Saccharomyces cerevisiae antibody 5%
55–65%
OmpC
E. coli
38–50% 2%
Anti-I2
Pseudomonas fluorescens
54%
Anti-Flagellin
CBir 1 Antigen
8-14%
50% 6%

12. OmpC+ ASCA+ I 2 + CBir1 ??? All Negative 9% 13% 22% 12% 2% 7% 26%
Interrelationships of Serum Immune Responses to Microbial Antigens in CD
CBir1
???
ASCA+
OmpC+ 9%
13%
22%
12% 2% 7%
26%
All Negative
I 2 +
Landers et al, Gastro. 123: , 2002

13. Serology as a predictor of Disease Behavior

14. Antibody Sum and Disease Behavior
NPNS
P trend < *
2.2
1.0
5.0
9.5 IP *
1.7
1.0
4.2
6.1
P trend < S
Surgery
Frequency of Disease Behavior %
N=199 1
N=262 2
N=194 3
N=57
* Odds Ratio
Number of Immune Responses
Dubinsky et al, Gastroenterology 2007; 132: 82

15. Proportion Acquiring First Surgery
ASCA and Surgery
1.00
0.75
P < 0.001
Proportion Acquiring First Surgery
0.50
0.25
Either ASCA negative
Either ASCA positive
0.00
500
1000
2000
Time in Days
Significant difference in time to first surgery observed in patients ASCA positive
Amre et al, Am J Gastroenterol. 2006;101:645.

16. High Level Pre-operative pANCA Predicts Chronic Pouchitis
78 %
Incidence of Pouchitis (%)
41 %
22 %
Fleshner PR et al., Gut 2001;49

17. IBD-7 Panel Combines pANCA/ASCA/OmpC/Anti-I2/CBir1 profiles
Provides composite prediction of UC/CD patterns vs. non-IBD
Does NOT provide individual probabilities
Not clinically intuitive
e.g. Low titer OmpC + alone may predict UC?

18. New serologic markers: carbohydrate antigens
913 well-characterized patients
Anti-glycan antibodies:
Anti-laminaribioside carbohydrate (ALCA)
Anti-chitobioside carbohydrate (ACCA)
Anti-mannobiodside (AMCA)
IgG gASCA
IgA Omp
Only gASCA 43.9%
ALCA 8.9%
2.7%
8.0%
4.9%
Ferrante--from Leuven group
Laminaribioside, chitobioside mannobiodside is found in cell walls of pathogenic bacteria and fungi
6.8%
15.9%
gASCA positive CD n=515
8.9%
ACCA
AMCA
Ferrante M, et al. DDW 2006, Los Angeles. Abstract #129

19. Serological markers can be used to discriminate IBD vs non-IBD
Individual markers
gASCA
ALCA
ACCA
AMCA
Sens
Spec
PPV
CD vs UC 56 90 95 18 93 21 85 82 28 84
IBD vs non-IBD GI 45 98
100 15 99 19 26
IBD vs HC 86 89 91
Combined scores
CSS ≥1.0
CSS ≥1.5
CSS ≥2.0
CSS ≥2.5
Sens
Spec
PPV
CD vs UC 74 61 86 54 83 91 37 93 94 20 97 96
IBD vs non-IBD GI 66 82 98 45
100 30 16
IBD vs HC 99
HC= healthy controls
Non-IBD GI--intestinal inflammation, no IBD
Got score of 0, 0.5 or 1 for each Ab marker depending on whether negative, intermediate or high respectively
Combinations of ASCA plus these new anti-carbohydrate markers improves the ability of tests to discriminate b/w Crohn’s disease and ulcerative colitis, inflammatory bowel disease vs. non-Inflammatory bowel disease intestinal inflammation. As the number and level of serologic markers increases, sensitivity decreases but specificity and PPV improves
Ferrante M, et al. DDW 2006, Los Angeles. Abstract #129

20. Complicated disease course Need for abdominal surgery
Serological markers to carbohydrate Ags can be used to predict CD course
Complicated disease course
Need for abdominal surgery
OR: 1.96 p=0.010
OR: 2.81 p<0.001
% patients
OR: 2.00 p=0.001
OR: 1.45 p=0.072
OR: 1.76 p=0.006
OR: 1.56 p=0.033
Ferrante--from leuven group
913 Crohn’s disease patients; 81% had complete phenotypic information
For the 5 antibodies they assigned a score of 0 for negative, 0.5 for intermediate, 1 for high level for the highest score of 5
-- COMPLICATED DISEASE COURSE means developing fistulas or strictures
Score <1.5
Score 1.5 or 2.0
Score 2.5 or 3.0
Score >3.0
Score <1.5
Score 1.5 or 2.0
Score 2.5 or 3.0
Score >3.0
Ferrante M, et al. DDW 2006, Los Angeles. Abstract #129
OR=odds ratio; p-value (Chi-square)

21. Serologic Markers: Current Status
pANCA is sensitive for colitis and high titers are bad prognosis for pouchitis
ASCA is specific for small bowel Crohn’s disease and high titers are bad prognosis for transmural complications
OmpC, Anti-Flagellin and I2 add sensitivity and specificity for Crohn’s disease
Predictive value is too low for clinical utility

22. ECCO Recommendations
No evidence based recommendation can be made with regards to the routine clinical use of: - genetic tests - stool markers - serologic markers (ASCA, ANCA,…ompC, I2, flagellin) - permeability testing - Phenotype driven classifications
(5,D)

23. C-Reactive Protein
High CRP better separates placebo from drug responders
Natiluzimab, CDP-571, CDP-870, Infliximab, Adalimumab, HuZaf
No distinct cut-off for CRP
Other biologic markers if low CRP
Fistula response, mucosal healing?
Currently not a regulatory criteria but improves “efficiency” of trials

24. CDAI and CRP Relationship at Baseline (logarithmic scale)

25. How to assess/treat these patients? CDAI/CRP at Baseline
Baseline CDAI
150
200
250
300
350
400
450
500
Log CRP mg/L
0.01
0.1 1 10
100
Low CDAI-High CRP
High CDAI-High CRP
ULN
Low CDAI-Low CRP
High CDAI-Low CRP

26. How to assess/treat these patients? CDAI/CRP at Baseline
Baseline CDAI
150
200
250
300
350
400
450
500
Log CRP mg/L
0.01
0.1 1 10
100
High
Responder
Low CDAI-High CRP
High CDAI-High CRP
ULN
Low CDAI-Low CRP
High CDAI-Low CRP

27. How to assess/treat these patients? CDAI/CRP at Baseline
Baseline CDAI
150
200
250
300
350
400
450
500
Log CRP mg/L
0.01
0.1 1 10
100
Low CDAI-High CRP
High CDAI-High CRP
ULN
High Placebo
Response
Low CDAI-Low CRP
High CDAI-Low CRP

28. How to assess/treat these patients? CDAI/CRP at Baseline
Baseline CDAI
150
200
250
300
350
400
450
500
Log CRP mg/L
0.01
0.1 1 10
100
Low CDAI-High CRP
High CDAI-High CRP
Clinical
Remission
ULN
Low CDAI-Low CRP
High CDAI-Low CRP

29. How to treat these various patients? CDAI/CRP at Baseline
Baseline CDAI
150
200
250
300
350
400
450
500
Log CRP mg/L
0.01
0.1 1 10
100
Early
Relapse
Low CDAI-High CRP
High CDAI-High CRP
ULN
Low CDAI-Low CRP
High CDAI-Low CRP

30. Conclusions CRP CRP is a predictor of placebo response
Efficacy signals in recent clinical trails may have been obscured by placebo responses in CRPlow patients

31. ECCO Recommendations Regarding CRP
Serum levels of CRP are useful to assess the patients’ risk for a relapse (B).
High CRP levels are indicative of active disease (B) or a bacterial complication (C).
CRP levels can be assessed to guide therapy and follow up (B).