title: Impact of disease location on fecal calprotectin levels in Crohn's disease.
abstract: OBJECTIVE
  The correlation between the Simple Endoscopic Score for Crohn's Disease (SES-CD) and fecal calprotectin is well established in (ileo)colonic Crohn's disease (CD). However, for ileal CD, existing data are conflicting. The aim of this study is to evaluate the biomarker profile in CD patients with varying severity and location of mucosal ulceration.
  
  
  METHODS
  An electronic patient database search identified CD patients in whom ileocolonoscopy, fecal calprotectin (CALPRO), serum C-reactive protein (CRP) and blood leukocyte counts (LEU) were measured within a 4-week interval without changes in medication. Ileocolonoscopies were scored for the presence of ulcers in each segment as defined by the SES-CD and the sum of segmental ulcer scores resulted in a partial SES-CD (pSES-CD).
  
  
  RESULTS
  Fourty-four patients were identified, of whom 9/44 had ileal CD, 20/44 colonic and 15/44 ileocolonic CD based on the Montreal classification. In the total study population CALPRO correlated best with pSES-CD (r = 0.76, p < 0.0001), followed by LEU (r = 0.54, p = 0.0004) and CRP (r = 0.45, p = 0.0026). Patients with ileal CD had significantly lower CALPRO level than those with (ileo)colonic disease even in the presence of large and/or very large ulcers (mean ± SEM: 297 ± 81 μg/g vs. 1523 ± 97 μg/g, p < 0.0001). LEU was also significantly lower in the presence of large and/or very large ulcers in ileal CD compared to those with (ileo)colonic disease (mean ± SEM: 6.7 ± 0.9 × 10(9)/l vs. 10.6 ± 0.8 × 10(9)/l, p = 0.02). A similar trend was identified regarding CRP levels.
  
  
  CONCLUSIONS
  Even in the presence of large or very large ulcers, patients with ileal Crohn's may not have markedly elevated fecal calprotectin levels.
authors: Department of Gastroenterology and Hepatology, Academic Medical Centre, University of Amsterdam , Meibergdreef 9, 1105 AZ Amsterdam , The Netherlands.
authors: Krisztina B
authors: KB
authors: Gecse
authors: Johannan F
authors: JF
authors: Brandse
authors: Sandra
authors: S
authors: van Wilpe
authors: Mark
authors: M
authors: Löwenberg
authors: Cyriel
authors: C
authors: Ponsioen
authors: Gijs
authors: G
authors: van den Brink
authors: Geert
authors: G
authors: D'Haens
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis; D003106:Colon / Q000503:physiopathology*; D003108:Colonic Diseases / Q000175:diagnosis*; D003113:Colonoscopy; D003424:Crohn Disease / Q000150:complications / Q000175:diagnosis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D006801:Humans; D007082:Ileum / Q000503:physiopathology*; D007958:Leukocyte Count; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D002097:C-Reactive Protein
keywords: Biomarker; CRP; Crohn’s disease; SES-CD; endoscopy; fecal calprotectin