title: Discriminating IBD from IBS: comparison of the test performance of fecal markers, blood leukocytes, CRP, and IBD antibodies.
abstract: BACKGROUND
  Symptoms of inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) can overlap. We aimed to determine the accuracy of fecal markers, C-reactive protein (CRP), blood leukocytes, and antibody panels for discriminating IBD from IBS and to define a "best test."
  
  
  METHODS
  We prospectively included 64 patients with IBD (36 Crohn's disease [CD], 28 ulcerative colitis [UC]), 30 with IBS, and 42 healthy controls. Besides CRP and blood leukocytes, blinded fecal samples were measured for calprotectin (PhiCal Test, enzyme-linked immunosorbent assay [ELISA]), lactoferrin (IBD-SCAN, ELISA), Hexagon-OBTI (immunochromatographic test for detection of human hemoglobin), and LEUKO-TEST (lactoferrin latex-agglutination test). Blinded serum samples were measured for the antibodies ASCA (ELISA) and pANCA (immunofluorescence).
  
  
  RESULTS
  Overall accuracy of tests for discriminating IBD from IBS: IBD-SCAN 90%, PhiCal Test 89%, LEUKO-TEST 78%, Hexagon-OBTI 74%, CRP 73%, blood leukocytes 63%, CD antibodies (ASCA+/pANCA- or ASCA+/pANCA+) 55%, UC antibodies (pANCA+/ASCA-) 49%. ASCA and pANCA had an accuracy of 78% for detecting CD and 75% for detecting UC, respectively. The overall accuracy of IBD-SCAN and PhiCal Test combined with ASCA/pANCA for discriminating IBD from IBS was 92% and 91%, respectively.
  
  
  CONCLUSIONS
  The PhiCal Test and IBD-SCAN are highly accurate for discriminating IBD from IBS. There is only marginal additional diagnostic accuracy when the PhiCal Test and IBD-SCAN are combined with ASCA and pANCA. ASCA and pANCA have a high specificity for IBD.
authors.affiliation: Department of Gastroenterology, Inselspital/University of Bern, Switzerland. alain.schoepfer@insel.ch
authors.forename: Alain M
authors.initials: AM
authors.lastname: Schoepfer
authors.forename: Michael
authors.initials: M
authors.lastname: Trummler
authors.forename: Petra
authors.initials: P
authors.lastname: Seeholzer
authors.forename: Beatrice
authors.initials: B
authors.lastname: Seibold-Schmid
authors.forename: Frank
authors.initials: F
authors.lastname: Seibold
mesh_terms: D000328:Adult; D000368:Aged; D000908:Antibodies, Fungal / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D002352:Carrier Proteins / Q000032:analysis; D003937:Diagnosis, Differential; D005243:Feces / Q000737:chemistry; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis*; D007781:Lactoferrin; D007958:Leukocyte Count; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000908:Antibodies, Fungal; D002352:Carrier Proteins; D006454:Hemoglobins; C490098:LTF protein, human; D039841:Leukocyte L1 Antigen Complex; D002097:C-Reactive Protein; D007781:Lactoferrin