title: Fecal calprotectin for evaluating postoperative recurrence of Crohn's disease: a meta-analysis of prospective studies.
abstract: BACKGROUND
  Fecal calprotectin (FC) levels have been extensively reported to correlate with clinical and endoscopic activities in Crohn's disease (CD); however, the utility of FC levels in the postoperative setting remains to be determined. Using meta-analysis, we aimed to evaluate the utility of FC as a noninvasive marker of recurrence in patients with CD who had undergone previous surgical resection.
  
  
  METHODS
  An electronic search using keywords related to CD and FC was performed in multiple electronic resources from 1966 to March 2014. The extracted data were pooled using a hierarchical summary receiver operating curve model.
  
  
  RESULTS
  Ten articles met the inclusion criteria, and methodological quality was determined in detail for each study. The 10 studies presented FC levels in 613 postoperative CD patients. The pooled sensitivity and specificity values for assessing suspected endoscopic recurrence were 0.82 (95% confidence interval (CI), 0.73-0.89, 8 studies, n = 391) and 0.61 (95% CI, 0.51-0.71), respectively. The overall positive and negative likelihood ratios were 2.11 (95% CI, 1.68-2.66) and 0.29 (95% CI, 0.197-0.44), respectively. The pooled sensitivity and specificity values for evaluating clinical relapse were 0.59 (95% CI, 0.47-0.71; 3 studies, n = 183) and 0.88 (95% CI, 0.80-0.93), respectively. The overall positive and negative likelihood ratios were 5.10 and 0.47, respectively.
  
  
  CONCLUSIONS
  As a simple and noninvasive marker, FC is useful in evaluating recurrence of postoperative patients with CD.
authors.affiliation: Departments of *Gastroenterology, †Pathology, ‡Surgery, and §Radiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Qiu
authors.forename: Ren
authors.initials: R
authors.lastname: Mao
authors.forename: Bai-li
authors.initials: BL
authors.lastname: Chen
authors.forename: Yao
authors.initials: Y
authors.lastname: He
authors.forename: Zhi-rong
authors.initials: ZR
authors.lastname: Zeng
authors.forename: Ling
authors.initials: L
authors.lastname: Xue
authors.forename: Xin-ming
authors.initials: XM
authors.lastname: Song
authors.forename: Zi-ping
authors.initials: ZP
authors.lastname: Li
authors.forename: Min-hu
authors.initials: MH
authors.lastname: Chen
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D003424:Crohn Disease / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D005243:Feces / Q000737:chemistry*; D006801:Humans; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex