Clinical impact of serologic testing for inflammatory bowel disease

April 2000

AGAAI03

mucosa of patients with IBD nor any reliable means of such quantitation. We aimed to determine [1] normal NO levels in control intestinal mucosal samples & [2] NO concentrations in mucosal biopsies of IBD patients with active or inactive disease. Methods: Endoscopic colonic mucosal biopsies (n = 6 to 8 / group, p
685 SCREENING WITH STABLE FAECAL PROTEINS - CAN THEY EXCLUDE GI PATHOLOGY? Simon S. Campbell, Gordon Brydon, Norman Anderson, Subrata Ghosh, GI Lab, Western Gen Hosp, Edinburgh, United Kingdom. Background: There is no simple GI screening tool available. Current faecal screening has largely relied on the presence of blood, but there has been recent interest in the use of faecal proteins as a more accurate method of screening. Aim: To evaluate quantitative detection of Calprotectin and Lactoferrin as an initial screening tool in GI patients and compare these with healthy controls. Methods: Patients presented with a variety of GI complaints. Seventy four patients provided 139 random faecal samples for analysis (mean age 47 years; 39 female:45 Male). Patients were grouped by final diagnosis; controls (34), IBD (35), CRC/polyps (II), IBS (34) and 'other' (20), which contained patients with pancreatitis, microscopic colitis and coeliacs. Mean concentrations of Calprotectin were compared between these groups and controls using Mann Whitney analysis. Sensitivity and specificity were calculated for both methods for its ability to exclude GI pathology. Results: With calprotectin, there were significant differences between controls (mean 6ug/g range 1-28)and all other categories (IBD mean 495uglg range 18-2410, CRC/polyp mean 214 uglg range 49-910, other mean 230uglg range 17-620; p
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686 CLINICAL IMPACT OF SEROLOGIC TESTING FOR INFLAM· MATORY BOWEL DISEASE. Christopher 1. Derbes, Joseph H. Sellin, U Texas Med Sch, Houston, TX. Background: Serological markers for Inflammatory Bowel Disease (IBD) including ANCA and ASCA have been shown to have high specificity and positive predictive value in diagnosing IBD. They may have utility in characterizing disease evolution and response to therapy. However, neither their indications for use nor their utility in clinical practice has been clearly established. Aim: Determine clinical impact of serologic testing in IBD by delineating how ANCNASCAs were utilized in an academic referral practice. Methods: Retrospective chart review to classify both the indications for testing and whether results had a significant effect on diagnosis or management. Results: Fifty-six patients underwent serologic testing from August 97 to November 99. None of these patients were tested to confirm well-defined ulcerative colitis or Crohn's disease. Indications included differentiating Crohn's from ulcerative colitis in established IBD (n=9, 16%); establishing a diagnosis in patients with atypical signs of inflammation as detected by endoscopy, pathology, or radiology (n=25,44%); evaluation of chronic diarrhea (n= 10, 18%); evaluation of a family history of IBD (n=3,5%); differentiating pouchitis from Crohn's (n=3,5%); and other (n=6, 10%). Review of the subsequent course indicated that serologic testing had an important role in diagnosis in 33%, a supportive role in 42% and was not helpful in 23%. Serologic testing had an immediate effect on therapy and/or management in 30%, a potential effect in 23% and no discernible effect in 44%. It proved particularly valuable in establishing a diagnosis of UC or Crohn's in a subset of middle-aged patients with inflammatory changes in the sigmoid colon. Serologic testing clarified the clinical presentation in 36% of those presenting with atypical inflammatory changes. In patients with chronic diarrhea, the yield was lower: 20% had a positive ASCA, but test results did not change immediate treatment in any. In patients evaluated for operation, serologic testing was valuable in clarifying the need/type of surgery. Conclusions: Serological testing for ANCNASCA had a significant role in individuals presenting with atypical inflammation, but less important in those with chronic diarrhea. A positive test for serolgoical markers of IBD may either alter the diagnosis or management of patients with signs and symptoms of colonic inflammation.

687 PERINUCLEAR ANTINEUTROPHIL CYTOPLASMIC ANTmOD· IES (PANCA) AND ANTI·SACCHAROMYCES CEREVISIAE (ASCA) ANTmODIES IN CHILDREN WITH INDETERMINATE COLITIS. Puneet Gupta, John A. Hart, Barbara S. Kirschner, Universty of Chicago, Chicago, IL; Univ of Chicago, Chicago, IL. ASCA and pANCA antibodies are being used to distinguish Crohn s disease (CD) and the ulcerative colitis (UC) respectively. Aim ofthis study was to evaluate usefulness of these antibodies in children with indeterminate colitis, defined in the pediatric literature as inflammatory bowel disease (IBD) of the colon with features suggestive of both UC and CD, without restriction to patients who have undergone colectomy Methods: Of 420 children with lBO, 41 children (9.8%) had indeterminate colitis. Pathology of these patients was reviewed for histologic features favoring CD or UC. ASCA and pANCA assays were performed at Prometheus Laboratories and results were compared with histologic findings. Results: Histologic features of colonic biopsies favored VC in 19 children (46%), CD in eight children (20%) and 14 children (34%) had no distinguishing histologic features favoring UC or CD. P-ANCA, type I, was positive in 17 patients, of which 13 (76%) had histology favoring Uc. Of the 13, six patients had areas of focal colitis, five had non-specific gastric or duodenal inflammation, one had anal fissures and one patient had isolated granuloma next to a ruptured crypt. Six patients were ASCA positive, of which three (50%) had histology favoring CD without radiologic features of CD. Three ASCA positive patients (50%) had biopsies favoring VC; two underwent subsequent colectomy and pathology of the colon was consistent with Vc. 18 patients were pANCA type 1 and ASCA negative, of which 12 (66%) had no distinguishing histologic features to favor UC or CD. Positive pANCA type I was 68% sensitive and 77% specific in diagnosing indeterminate colitis with histologic features favoring UC (p<0.02). Positive ASCA was only 37% sensitive but 88% specific in indeterminate colitis with histology consistent with CD . Conclusion: pANCA is useful in selecting a subset of indeterminate colitis patients with histologic features favoring UC. The presence of ASCA antibodies had a low positive predictive value (50%) for histologic features suggestive of Crohn s colitis.

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