title: Low Fecal Calprotectin Correlates with Histological Remission and Mucosal Healing in Ulcerative Colitis and Colonic Crohn's Disease.
abstract: BACKGROUND
  Data regarding the correlation of histologic and endoscopic healing with fecal calprotectin (FC) are conflicting. We examined how FC levels correlate with histological and endoscopic remission in colonic inflammatory bowel disease.
  
  
  METHODS
  Fifty-eight patients (23 with colonic Crohn's disease [CD] and 35 with ulcerative colitis [UC]) were included. Clinical activity was assessed by Harvey-Bradshaw index (CD) and Mayo score (UC). Inflammatory activity was assessed by ileocolonoscopy, C-reactive protein, and FC. Clinical remission was defined as Harvey-Bradshaw index ≤ 4 or Mayo score ≤ 2 and mucosal healing as Mayo endoscopic subscore = 0 (UC), and Simple Endoscopic Score-CD <3 (CD). Histologic activity was assessed in 27 patients (15 CD, 12 UC). Histological remission was defined as absence of active inflammation (Geboes score <3.1) and absence of basal plasmacytosis.
  
  
  RESULTS
  In UC, FC correlated with clinical Mayo score (r = 0.63, P < 0.0001). This correlation was strengthened by adding the endoscopic subscore (r = 0.90, P < 0.0001). The endoscopic subscore also independently correlated with FC (r = 0.96, P < 0.0001). In Crohn's colitis, endoscopic activity correlated with FC (r = 0.61, P < 0.001). FC levels were lower overall for patients with endoscopic remission compared with active endoscopic disease (median 100 versus 1180 μg/g, P < 0.0001). FC also correlated with histological remission (Geboes score < 3.1) and absence of basal plasmacytosis in CD (r = 0.77, r = 0.80, respectively; P < 0.01). Area under the curve for FC as a predictor of histological remission (Geboes score <3.1) was 0.95 (95% CI, 0.82-1).
  
  
  CONCLUSIONS
  Low FC correlates well with histological remission and mucosal healing in colonic inflammatory bowel disease and is thus a clinically useful surrogate for inflammatory activity.
authors.affiliation: *Mount Sinai Hospital, Zane Cohen Center, University of Toronto, Toronto, ON, Canada; †Pathology and Lab Medicine, Mount Sinai Hospital, Zane Cohen Center, University of Toronto, Toronto, ON, Canada; ‡Mount Sinai Hospital, Zane Cohen Center, Toronto, ON, Canada; §Mount Sinai Hospital, Zane Cohen Center, University of Toronto, Luenefeld-Tannenbaum Research Institute, Toronto, ON, Canada; ‖University of Leuven, Leuven, Belgium; and #Institute of Gastroenterology and Liver Diseases, Ha'Emek Medical Center, Afula, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Zittan
authors.forename: Orlaith B
authors.initials: OB
authors.lastname: Kelly
authors.forename: Richard
authors.initials: R
authors.lastname: Kirsch
authors.forename: Raquel
authors.initials: R
authors.lastname: Milgrom
authors.forename: Jane
authors.initials: J
authors.lastname: Burns
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Nguyen
authors.forename: Ken
authors.initials: K
authors.lastname: Croitoru
authors.forename: Gert
authors.initials: G
authors.lastname: Van Assche
authors.forename: Mark S
authors.initials: MS
authors.lastname: Silverberg
authors.forename: A Hillary
authors.initials: AH
authors.lastname: Steinhart
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000378:metabolism / Q000473:pathology*; D003424:Crohn Disease / Q000378:metabolism / Q000473:pathology*; D004724:Endoscopy; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000737:chemistry*; D005260:Female; D005500:Follow-Up Studies; D006651:Histocytochemistry; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology*; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D012372:ROC Curve; D012074:Remission Induction; D012720:Severity of Illness Index; D014945:Wound Healing; D055815:Young Adult
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D002097:C-Reactive Protein