Evaluation of serologic testing for inflammatory bowel disease (IBD) in children

of disease extent were represented. The mean SIBDQ score was 48.4 (13o70). The mean difference betweenpatientsin remissionand relapsewas -20.1 (95%CI -25.1 to -15.1) p
four ELISA assays were simultaneously optimized by Design of Experiments software to maximize clinical sensitivity in the IBD First Step and maximize specificity in the Diagnostic System. Results: Using a study population of 68.4% IBD prevalence,an optimized set of cutoff values was developed using all four of the serum markers. The addition of anti-OmpC improved the clinical sensitivity and negative predictive value (NPV) of the IBD First Step in this study from 89.1% to 94.2%, and from 68.4% to 79.2%, respectively,for IBD (both UC and CD together). With the inclusion of anti-OmpC, clinical specificity and positive predictive value (PPV) of the overall IBD Diagnostic System remained high at 91.3% and 94.9%, respectively,for IBD. IgA antibodies to OmpC were present in 27.9% of the Crohn's disease patients that were negative for ASCA. Conclusion: The addition of anti-OmpC as a fourth marker results in improved clinical sensitivity and specificity for the serologic diagnosisof IBD.

1420 Is Serology fro' Ulcerotiva Colitis and Crohn's Disoase an improvement on Existing Scmmdq Tests for lidlammatory Bowel Disuse (IBO) in Children?

O

Khaitd Khan, Univ Of Minnesota, Minneapolis, MN; David Ferrenci, Minnesota G a s ~ r o l o o y , Minneapolis, MN; Sara Jane Schwarzenberg,Univ of Minnesota, Minneapolis, MN; Michelle Kennedy,Arumagam Ramalingham, Richard Stafford, Minnesota Gastroenterology, Minneapolis, MN; Debra Greenwood, Sally Weisdnrt, Univ of Minnesota, Minneapolis, MN

t3ackoroond:Histoiooy is required for diagnosing IBD, however serologicaltests are proposed as useful in screening for IBD. We examinedperinuciear staining anti-neutrophil cytoplasmic antibody (pANCA), a marker for UC and anti-Saccharomyces ceravisiae antibody (ASCA), a marker for CD, in selecting children for cnlonoscopy and comparedthis to existing screening tests hemoglobin (Hgb) and erythrocyte sedimentationrate (ESR). Method: Over an 18 month period children being investigated for IBD had blood analyzed for pANCA (UC-Dx-1) and ASCA (CD-Dx-1) through Prometheus laboratories (san Diego, CA). Hemoglobin, ESR and colonoscopy were performed as per routine. The results of serology were compared to Hgb and ESR in predicting positive histology. They were also combined to see if screening could be improved comparedto serology or routine tests alone (analysis: sensitivities, speoiflcities and X2). Results: One hundred and sixty two children were investigated,47 were diagnosed with UC, 33 had CD, 15 had indeterminate colitis (IC) and 5 had eosinophilic enterocolitis (EC). Of those with UC 42/47 were ANCA+, 2/47 ASCA +, and 26/47 had abnormal Hgb or ESR. Of the Crohn's cases 16/33 were ASCA +, 2/33 ANCA +, and 19/33 had abnormal HOb or ESR. Two of 15 with IC were serology (1 ANCA, 1ASCA) positive and 5/15 had abnormal Hgb or ESR. One child with EC had increased ESR. Of children without IBD 2/61 were ASCA +, 2/61 ANCA + and 13/61 had abnormal Hgb or ESR.Sensitivity and specificity of ANCA for UC, were 89% and 96% respectively,of ASCAfor CD were 49% and 95%. The values for combined ANCA, ASCA, Hgb and ESR were as follows:[TABLE] Comparing the differences in the rates of positive tests for screening IBD, X2= 5.85, p=O.1 Conclusion: For diagnostic screening of symptomatic children for IBD serum ANCAwas the most reliable blood test in indicating UC. The value of ASCA in screeningfor Crohn's diseasewas similar to Hgb and ESR in screeningfor IBD.There was no statistically significant difference between Hgb and ESR compared to serology in screening for IBD.

\ \ \\\ %

1418 Combining Serologic AntibodiesASCAAnd Anti-OmpC Iocroavas Sensitivity For Crohn's Disease (CD), Severine Vermeire, Sofie Joossens, Nele Esters, Univ Hosp Gasthuisberg - Dept Gastroenterology,Leuven Belgium; Robert Vlinfinck, Univ Hosp Gasthuisberg - Human Genetics and Epidem, Leuven Belgium; Paul Rutgeerts, Univ Hosp Gasthuisberg - Dept Gastroenterology,Leuven Belgium Introduction & Aim: Microbial agentsare suspectedto be pathogenicinitiators in inflammatory bowel disease(IBD). Antibodies againstthe yeast Saccharomyces cerevisiae (ASCA)are found in about 60% of CD patients,but their meaningremains unknown. Recently,antibodiesagainst an Escherichia coil protein have been identified in IBD. These antibodies recognisethe outer membrane porin C of Ecoliand anti-OmpC IgA has a specificity towards CD. These markers individually carry incomplete sensitivity to be used as non-invasive screening tools. Using a panel of markers has therefore been proposed. We undertook a large study in IBD patients and controls to see whether combining ASCAand OmpCcan increases e n ~ , and whether they expressdifferent pbenotypesof CD. Methods: 197 IBD patients (99 CD-95 UC), 78 nonIBD intestinal inflammatory controls and 100 healthy controls were tested for ASCA(IgA and IgG) and Anti-OmpC IgA at Prometheus Laboratories (san Diego, CA) by specific ELISA techniquesin a blindedway. Fromall patients, detaileddemographicand clinical obaraetedstics on age, sex, age at onset of disease,Incalisation, surgery and diseaseactivity, were obtained and analysedby stepwise logistic regression using the SASISTATRelease8.01 software (SAS Institute Inc,, Raleigh, NC). Significance levels were reachedat a= 0.95. Results: Sensithtity, specificity, PPV and NPV of ASCAfor CD were 82.2%, 93.5%, 78.2% and 87.2% respectively. Combining ASCAand Anti-OmpC,the respectiveaccuracydata became72.4%, 84.5%, 62.8%, and 89.3%. Colon involvement was the only variable correlated with Anti-OmpC (p=0.043, OR=0.359, 95% CI =0.133-0.970). No clinical variables were associatedwith ASCAoverall. However,ASCAIgG alone was associatedwith colon Iocalisation(p = 0.0362, OR= 2.87, 95% C1=1.07-7.7). In this group with colonic involvement, significance increased when age at onset was<25 years (p = 0.0189, OR= 4.431,95% CI 1.279-15.350). Conclusion:Combining ASCA and Anti-OmpC increasessensitivity for CD with about 10% but decreasesspecificity. The important overlap in positivity seen betweenthese 2 markers, might reflect cross-reactive bacterial recognition by T-cells. Phenotypic analysis identified colonic CD, and colonic CD with a young age at onset <25 years as the most important risk factors for developingAntiOmpC and ASCA lOG, respectively.

CO-Dx-1for CD + UC-Dx-I fix UC

CD-Dx-I+UCDx-t for IBD OBD-Dx-t)

_*Hgbor ;tESRfor IBD

_IBD-Ox-I+ (Hgb ÷ESR)

S4mdev~ %

73

75

56

88

,sed~ %

94

94

94

77

*l-tgb : < 11.5 g/all tESR : > 15mmHgfor under16 yrs, >20mmHgfor 16 yrs and over

Evaluation of Serologic Testing for inflammatory Bowel Disease (IBD) in Children Brian Fagan,NeeleshTipnis, Joel Lavine, Sharon Taylor, Ranjan Dohil, Univ of CA Joint Program in Ped Gastroenterology,San Diego, CA The diagnosis of IBD, and the differentiation between Crohn's disease (CD) and ulcerative colitis (UC) in children using conventional criteria may be unsatisfactory. Perinuclear antineutrophil cytoplasmic antibody (pANCA)and anti-Saccharomyces cervisiae antibody (ASCA) assays are now commercially availableand reportedly helpful, pANCAhas been found in 6090% of adults with UC and ASCA in 60-70% of those with CD. Aim: To determine whether pANCAand ASCAare of value in diagnosing IBD, and differentiating between CD and UC in children. Methods and Results: 66 children, 39 girls and 28 boys (ages 3-20, mean 11.9y) had a First Step (FS)TM screening test _+pANCAand ASCA titers measured as part of their evaluationfor IBD (PrometheusLabs). Diagnosis of IBD was made using conventionalcriteria and confirmed by 2 pediatric gastroenterologists. Each patient was assigned to one of six categories: Definite UC (14 children), Probable UC (10), Indeterminate colitis (6), Probable CD (5), Definite CD (15) or Non-IBD (16). Non-IBD children had: infection (3), gastritis (2), esophagitis (2), rectal polyp (1) and undetermined (8). Pancolitis alone was found in 12 children (UC 8, CD 2, Probable CD 1, infection 1). The First Step~was positive in 44 of 51 (86%) children with IBD. pANCAor ASCAtiters were elevatedin 32 of 51 children with IBD, but not in Non-IBD children. In children with pancolitis, 7 of 8 children with UC and the child with probable CD, whereas elevatedASCA titers were found in 1 of 8 children with UC and 1 of 2 children with CD. (See Table). Conclusions: (1) In children, positive pANCAor ASCA is a good confirmatory test, but a poor screening test for IBD (100% specificity and positive predictive value, 63% sensitivity, 46% negative predictive value), (2) pANCA can diagnose UC/probabla UC reasonablywell (83% sens., 75% spec., 80% PPV, 79% NPV). (3) ASCA confirms CD well, but is a poor screening test for CD in children (96% spec. 35% sens., 88% PPV, 64% NPV).

1419 Optimization of Four IBD Serology Markers for Increased IBO OiallnOMluAccuracy. Esther Oh, Carl Lacerte, Chris Sutton, Steven Rose, Prometheus, San Diego, CA; Carol J. Landers, Cedars-Sinai Medical Ctr, Los Angeles, CA; Jonathan Braun, UCLA, Los Angeles, CA; Stephan R. Targan, Cedars-SinaiMedical Ctr, Los Angeles, CA

Background/Purpose:The IBD serological markers ASCAand pANCAare useful adjuncts for the diagnosis of IBD, both being highly specific (>90%) for CD and UC, respectively.A subset of IBD patientsdo not expressthese antibodies. Recently,an outer membrane protein (OmpC) from E. co/iwas identified as a cross-reactive epitope of pANCAantibodies; antibodies from Crohn's disease sera have also been shown to bind to OmpC, including many patients who tested ASCA-negative(Landers, et aL, AGA, 2001). The Prometheus/BO Rrst Step and/BD Diagnostic System utilize the disease specific qualities of ASCA and pANCAto differentiate between IBD patientswith UC and CD, and from those with other GI diseases,thus facilitating IBD diagnosis. The goal of this study was to determinethe performanceof the IBD Rrst Step diagnostic system with anti-OmpC incorporated as an additional marker (IBD First Step and Diagnostic System Generation/I). Methods: IgA antibodiesto OmpCwere detected by a solid phase immunoassayin which OmpCantigen purified from E. coliwes immobilizedon microtiter plate wells. ASCA(IgA and IgG), pANCAand OmpCantibodieswere determinedon 402 serum samples consisting of 175 CD and 100 UC (classified together as IBD), and 127 non-IBO controls. Diagnosis of IBD patients was previously established by colonoscopic/radiologic/ histologic methods. All samples were tested in a blinded fashion. The cut-off values of all

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1424

SerologyResultsby Diagnosis n (%) FS * pANCA÷ ASCA.~

Def. UC(14) 14 (100) 13 (93) 1 (7)

Prob UC(t0)

Indeter rain. (6) 5 (83) 1 (17) 0

9 (90) 7 (70) 0

Prob CO(5) 5 (tO0) 3 (60) 1 (20)

Def. CD(15) 11 {73) 2 (13) 6 (40)

Biopsy Pathology Predicts Patients With Ulcerative Colitis Subsequently Requiring Surgery Masanori Tanaka, Hiroshi Saito, Tomomi Kusumi, Tadashi Shimoyama, Shinsaku Fukuda, Takayuki Morita, Hirosaki Univ Sch of Medicine, Hirosaki Japan; Akira Sugita, Masamichi Hara, Yokohama City Univ Medical Ctr, Yokohama Japan; Hajime Kudo, Hirosaki Univ Sch of Medicine, Hirosaki Japan

NonIBD(16) 6 (38) 0 0

1422 Endoscopic and Hislologic Evaluations are Necessary for the Diagnosis of PoucbiUs Be She& Jean-Paul Achkar, Adrian Ormsby, Brat A. Lashner, FezaRemzi, Charles L. Bevins, Aaron Brzezinski, Marlene L. Bambrick, Douglas L. Seidner, Victor W. Fazio, Cleveland Clin, Cleveland,OH Pouchitis is the most common long-term complication after total proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerativecolitis (UC). Patients often are diagnosed with pouchitis based on symptoms such as increased stool frequency, rectal urgency, abdominal cramps and are treated empirically. Few patients undergo endoscopic and histologic evaluations. AIM: To prospectivelystudy correlation betweensymptoms, endoscopic and histologic findings in UC patientswith normal pouches (UC-NP)orwith pouchitis (UC-Pouchitis). METHODS:46 patientswith UC and IPAAwere evaluatedwith the 18-point Pouchitis DiseaseActivity Index(PDAI). Patients were categorized into 2 groups: UC-NP (PDAI < 7) or UC-Pouchitis (PDAI - 7). In both groups, symptom and endoscopic scores ranged from 0 to 6, while histologic scores, ranged from 2 to 6. Endoscopic scores were recorded based on the consensusof two endoscopists,and histoiogic scoreswere blindly recordedby a GI pathologist. RESULTS:The demographicsof the two groups were similar. The meantotal PDAI, symptom, endoscopy, and histologic scores (_+ SD) were 4.2 _+ 1.5, 1.6 - 1.5, 0.4 + 1.9,and 2.2 _+ 0.5, in UC-NP and 10.2 _+ 2.3, 3.0 _+ 1.1, 3.9 _+ 1.6, and 3.2 _+ 1.0,in UC-Pouchitis. There was poor correlation betweensymptom, endoscopy,and histology scores in both groups, with Pearsoncorrelationcoefficient(r)rangingfrom -0.26 to 0.20 (P> 0.05)(Table).CONCLUSIONS: 1)The symptoms, endoscopy, and histology all contributed substantially to the PDAI; 2)The poor correlation between individual components of the PDA[ indicates that these are nearly independentfactors. It therefore requires a very high score of each individual component to reach the "diseased" status, PDAI _> 7, or a combination of moderately elevatedscores of 2 or 3 components;3)Symptoms could be due to factors other than pouchitis, and symptoms alone are not reliable to direct treatment in patients with IPAA. UC-NP(N = 24) Symptomvs Endoscopy Endoscopyvs Histology Symptomvs Histology

UC-PouchiUs(N = 22)

r

P-value

r

P-value

-0.26

0.22

0.06

0.78

-0.23

0.27

-0.12

0.58

-0.08

0.69

0.20

0.35

1423 Does Histology Predict Clinical Relapse In Ulcerative Colitis? Daniel W. Hommes, Fibo J W Kate, Miranda D M Roskam-Mul, Martin H. Prins, Gerben J. Sterringa, Guido N.J. Tytgat, Sander J H Deventer,Acad Medical Ctr, Amsterdam Nethedands Introduction. It is well known that colonic biopsies taken from patients with ulcerativecolitis (UC) in remission frequently show signs of inflammation. However,the predictive accuracy of these findings for relapse of disease have not been established.Therefore, we studied the correlation of baseline histological characteristics of biopsies from UC patients in remission with both endoscopical-and clinical relapse of disease. Methods. During a large prospective maintenancestudy of UC patientsin remission,biopsiesweretaken during baselineendoscopic evaluation according to a predefined manner. Patientswere then monitored during 9 months after which endoscopic-, clinical- and histological diseaseactivity was assessed. Histological grading was performed using predefinedparameterswhich included ulceration,erosion, crypt abscessesand cryptitis. Each item was scored using a severity scale, with a maximum score of 24 points. Remission (0 or 1 point) and relapse (>1 points) were predefined. Endoscopic videotapes were centrally scored in a blinded fashion by two experiencedand independent endoscopists. Results. In a total of 192 UC patients both histological- and endoscopicassessments were evaluated,At baseline, with all UC patients in. remission, cryptitis was found in 50 biopsy specimens (26%), crypt abscesses in 24 (12.5%), erosions in 14 (7.3%) and 2 ulcers (1%) were observed. A significant correlation was observed between erosions in baseline histological specimens and endoscopic relapse at 9 months (p<0.O5). Also, the presenceof ulcerationcorrelated significantly with endoscopic relapseat 9 months (p = 0.02). The other histological parameterswere not correlated with endoscopic relapse at 9 months. The negative predictive values (NPV) were similar between the 4 parameters (range 0.72 0.76). Conclusion. Inflammatory changes are a common finding in biopsy specimens taken from UC patients in remission. The presence of erosions or ulcerations in the histological assessment of macroscopically non-inflamed colonmucosa predict endoscopical relapse.

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BACKGROUND:The clinical course of patients with ulcerative colitis (UC) is unpredictable, and 17-38% ultimately require surgery. We hypothesizedthat mucosal histology may differ between patients requiring surgery (UC-S) and those receiving medication alone (UC-M), leadingto comprehensivecriteria consisting of specific bistologic features enablingthe prediction of failure to medicaltreatment. METHODS:We studied colorectal biopsy specimensfrom 157 patientswith active UC (67 with UC-Sand 90 with UC-M), and conductedmultiple logistic regression analysis on 70 histologic features, and also endoscopic diseaseextent and patient age. The analysis constructed an equation finding probability of UC-S (Puc.s). Based on a receiver-operatingcharacteristic curve, we selected4 cutoff values of probability, and determined criteria of 5 categories "highest-risk (Puc-s_>0.90)","higher-risk (0.75-