Serum Markers: What WhoSerum Markers: What, Who, When … · Serum Markers: What WhoSerum Markers:...
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Serum Markers: What WhoSerum Markers: What WhoSerum Markers: What, Who, Serum Markers: What, Who, When and Why?When and Why?
Sunanda Kane, MD, MSPH, FACG, FACP, AGAFAssociate Professor of Medicine
Mayo Clinic
Crohn’s Disease:Crohn’s Disease:Microbial AntibodiesMicrobial Antibodies
ASCA Anti- Saccharomyces cerevisiae
Anti-I2 Protein from pseudomonas fluorescens
Anti-OmpC Escherichia coli outer membrane porin
Bir1 Flagellin Antibodies to CBir FlagellinBir1 Flagellin Antibodies to CBir Flagellin
Targan S. Gastroenterology 2005;128(7): 2020-8
Combining Markers Improves Sensitivity Combining Markers Improves Sensitivity but Not Overall Accuracybut Not Overall Accuracy
Relationships of Serum Responses in CD
Total = 68% T t l 84%Total = 68% Total = 84%
Adapted from Landers CJ, et al. Gastroenterology. 2002;123:689-699.
Antibodies to CBir1 Antibodies to CBir1 FlagellinFlagellin
• Antigen of the gut flora• Antigen of the gut flora• Induces a strong B cell and CD4+ T cell
response in colitic miceresponse in colitic mice• 50% of patients with Crohn’s disease
have serum reactivityhave serum reactivity• Little or no reactivity in UC, inflammatory
controls, and normal controls,
Targan S. Gastroenterology 2005;128(7): 2020-8
Immune ResponseImmune ResponseCD PatientsCD Patients
60
555655
40
50
s
30
40
of P
atie
nts
23
10
20% o
0ASCA
1Anti-OmpC
1Anti-CBir1
2pANCA
1
1. Adapted from Landers CJ, et al. Gastroenterology. 2002;123:689-699.2. Targan SR, et al. Gastroenterology. 2005;128:2020-2028.
AntiAnti--CBir1 Presence CBir1 Presence CD PatientsCD Patients
3.)
50%2ody
(O.D
% % %
50%
1Bir1
Ant
ibo
8% 14% 6%
0
1
Ant
i-CB
n=40 n=21 n=50 n=100
0Normal
ControlsInflammatory
Controls UC CD
P vs CD:% Positive <0.001 <0.02 <0.001 n/a
Level <0.001 <0.003 <0.001 n/a
Targan SR, et al. Gastroenterology. 2005;128:2020-2028.
AntiAnti--CBir1 Helps Distinguish CBir1 Helps Distinguish Between pANCA+ PatientsBetween pANCA+ Patients
3
)
44%P<0.001 (level)
2
Bir1
(O.D
. 11/25
4%1
Ant
i-CB
1/254%
0.623
0pANCA+
UCpANCA+
CD
0.255
Targan SR, et al. Gastroenterology. 2005;128:2020-2028.
Performance Comparison:Performance Comparison:Crohn’s DiseaseCrohn’s Disease
ASCA & ANCAASCA+ ASCA+ & pANCA-97%88%
49%61%
Sensitivity Specificity Sensitivity Specificity
In a clinical study, serum samples from 100 CD,101 UC and 2 li id /di h l i d 163 l l d i
Sensitivity Specificity Sensitivity Specificity
N=391 (51% IBD, 50% CD, 50% UC)
Quinton JF, et al. Gut. 1998;42:788-791.
27 colitides/diarrheal patients and 163 controls were analyzed using pANCA IFA and ASCA ELISA
Performance Comparison Ulcerative ColitisPerformance Comparison Ulcerative Colitis
ANCA+ pANCA+ & ASCApANCA+ pANCA+ & ASCA-97%
85%
65%57%
65%
Sensitivity Specificity Sensitivity Specificity
N=391 ( 51% IBD, 50% CD, 50% UC)
In a clinical study, serum samples from 100 CD,101 UC and
Sensitivity Specificity Sensitivity Specificity
Quinton JF, et al. Gut. 1998:42:788-791.
y27 colitides/diarrheal patients and 163 controls were analyzed using pANCA IFA and ASCA ELISA.
Prometheus IBD Serology 7Prometheus IBD Serology 7
IBD Predicted
PROMETHEUS IBD Serology 7Overall Performance
IBD CD UC
Sensitivity 93% 88% 93%
Test Result
IBD Predicted
IBD Not Predicted
Ulcerative Colitis PredictedPROMETHEUS Predictive Algorithm Description:• Utilizes Smart Diagnostic Algorithm (SDA) technology to
Specificity 95% 98% 97%
PPV 96% 96% 89%
NPV 90% 93% 98%
Ulcerative Colitis Predicted
Crohn’s Disease Predicted
• Utilizes Smart Diagnostic Algorithm (SDA) technology tocharecterize complex relationships between markers to producea diagnosic prediction with greater accuracy than simple comparison of assay results to a reference range.
• Developed (n=1813; 36% CD, 24% UC, 20% IBS, 20% normal) and validated (n=500; 38% CD, 21% UC, 41% normal) using serology results for samples with a known diagnosis
ASCA lgA ASCA lgG Anti-OmpC Anti-CBir1
Neutrophi-Specific Nuclear Auto Antibodies (NSNA) (IBO Specific pANCA)
Auto Antibody IFA Perinuclear DNAse
Assay Information
AssayASCA lgA
ELISAASCA lgG
ELISAAnti OmpC
lgA ElisaAnti CBir1
ELISAAntibody ELISA
IFA Perinuclear Pattern Sensitivity
Assay Value : 109.4 EU/ml 113.8 EU/ml 26.0 EU/ml 50.2 EU/ml <12.1 EU/ml NOT Detected NOT Detected
Note: Test result determined by the PROMETHEUS Predictive Algorithm without direct consideration of assay values relative to reference values. However, interpretation of prognostic information should be made based on relative differences between assay values and reference values
Reference Values <20.0 EU/ml <40.0 EU/ml <16.5 EU/ml <21.0 EU/ml < 12.1 EU/ml Not Detected Not Detected
Progression of CD and Response to Progression of CD and Response to Microbial Antigens Scottish PopulationMicrobial Antigens Scottish Population
Number of Positive Antibodies* (%)0 1 2 3 P Value OR (3:0)
Disease Progression 24 52 73 87 <0.001 20
Surgery 32 57 52 89 <0.001 17
*Antibodies tested: ASCA, anti-OmpC, anti-I2
Adapted from Arnott ID, et al. Am J Gastroenterol. 2004;99:2376-2384.
Association of ASCA and Early Surgery Association of ASCA and Early Surgery Newly Diagnosed CD PatientsNewly Diagnosed CD Patients
Early Surgery( 35)
No Early Surgery ( 35)
P Value OR(n=35) (n=35)
ASCA IgA 63% 20% .001 8.5
ASCA IgG 40% 14% .027 5.5
ASCA IgA & IgG 37% 14% .043 5.0
Adapted from Forcione DG, et al. Gut. 2004;53:1117-1122.
High ASCA High ASCA IgAIgA & & IgGIgG in CD Associated With in CD Associated With More Aggressive Small Bowel DiseaseMore Aggressive Small Bowel Disease
100B
owel
ge
ry 86%P<0.0001
50
75
With
Sm
all
uirin
g S
urg
57%pANCA+ (≥40) & ASCA-All OthersASCA IgG & IgA + (≥50)
25
Pat
ient
s W
ease
Req
u
29%and ANCA-
0CD Subgroup
% o
f PD
ise
7 99 14
Adapted from Vasiliauskas EA, et al. Gut. 2000;47:487-496.*Other Investigators: Sands, Dassopoulos, RiisSimilar results
n=7 n=99 n=14
Frequency of Complications Increases With Number Frequency of Complications Increases With Number of Serologic Markers Children With CDof Serologic Markers Children With CD
/Stenotic OnlyNonperforating Nonstenotic Perianal Perforating Only Internal Perforating/Stenotic Only
S l i k8090
100
avio
r (%
)
Nonperforating Nonstenotic Perianal Perforating Only Internal Perforating
11.0*
Serologic markers:ASCA Anti-OmpC Anti-CBir1 Anti-I250
607080
isea
se B
eh
1.9* 2.3*5.5*
Anti I2
10203040
uenc
y of
Di
n=40 n=60 n=42 n=29 n=12
010
0 1 2 3 4
No. of Immune Responses
Freq
u
Dubinsky M, et al. Am J Gastroenterol. 2006;101:360-367.
(P trend=0.002)*Odds ratios
No. of Immune Responses
AntiAnti--microbial responsiveness is microbial responsiveness is increased in NOD2 mutant carriersincreased in NOD2 mutant carriers
• Mutations in Nod2 may decrease innate immune clearance of bacteria leading y gto secondary increase in adaptive immune responses
• Analyzed 732 Crohn’s disease patients, 220 healthy relatives, 200 controls• Nod2 mutant carriers have higher titers of anti-microbial antibodies:
CBir1 I2 ASCA OmpC
10 46
11.26
11.0
11.5
CBir1, I2, ASCA, OmpC
p-trend = 0.002
sum
9.72
10.46
9 5
10.0
10.5
n qu
artil
e
8.5
9.0
9.5
WT 1 t 2 t
Mea
n=499 n=194 n=39
WT 1 mut 2 mutNOD2/CARD15 Variant status
One way ANOVADevlin S, et al. DDW 2006, Los Angeles. Abstract #442
Potential Roles for IBD SerologyPotential Roles for IBD Serology
• Help identify IBD in patients with unclear diagnosis (but chronic inflammation already established)Help assess the need for endoscopy in patients who• Help assess the need for endoscopy in patients who are suspected of having IBD (pediatric population)
• Help differentiate between CD and UC• Help differentiate between CD and UC• Help improve the accuracy of diagnosis prior to
surgery (eg, colectomy, IPAA)surgery (eg, colectomy, IPAA)• Help identify patients at risk for aggressive disease
behavior
Indeterminate Colitis:Indeterminate Colitis:Value of SerologyValue of Serology
100 80%
Leuven, Lille, Vienna 97ptDefinite Diagnosis 31pt70
8090
100 64%
Definite Diagnosis 31pt pANCA- / ASCA - 40pt
40506070
UC pANCA+/ASCA
102030
UC pANCA+/ASCA-
CD pANCA-/ASCA+
0
Joossens S. Gastroenterology 2002. 122(5): 1242-47Joossens S. Gastroenterology 2003. 124: A323
IBD IBD SerologiesSerologies: When to order?: When to order?
• IC / Colectomy is planned (UC vs CD,IC / Colectomy is planned (UC vs CD, pouchitis risk)
• Pediatric: low suspicion • Mainly extra-intestinal manifestations (is it IBD?)
– Ankylosing spondylitisA th iti– Arthritis
– Pyoderma gangenosum– UveitisUveitis
• Second opinion / questionable diagnosis• Prognostication: ready for prime time?g y p
– Expensive: will insurance cover?
IBD Serologies: SummaryIBD Serologies: Summary
• Identify IBD in cases of diagnostic uncertainty• Assess the need for invasive endoscopy in• Assess the need for invasive endoscopy in
patients who are suspected of having IBD• Differentiate between CD and UCDifferentiate between CD and UC• Identify patients at risk for aggressive disease
behaviorbehavior• Insurance / cost still an issue