title: Comparison of fecal pyruvate kinase isoform M2 and calprotectin in assessment of pediatric inflammatory bowel disease severity and activity.
abstract: OBJECTIVE
  Accurate assessment of inflammatory bowel disease (IBD) activity is the cornerstone of effective therapy. Fecal M2 isoform of pyruvate kinase (M2-PK) and fecal calprotectin (FC) are noninvasive markers of mucosal inflammation in IBD. The aim of this study was to compare performance of M2-PK and FC in assessment of pediatric ulcerative colitis (UC) and Crohn's disease (CD) severity and activity.
  
  
  METHODS
  121 patients with IBD, including 75 with UC and 46 with CD were recruited. Control group consisted of 35 healthy children (HS). Patients were assigned to groups depending on disease severity and activity. M2-PK and calprotectin concentration were determined in stool samples using ELISA. Areas under receiver operating characteristic curves (AUC) for FC and M2-PK with cut-off level at which M2-PK specificity was matching FC specificity were calculated and compared.
  
  
  RESULTS
  Performance of M2-PK at identifying patients with IBD, UC and CD among HS was inferior to FC. The differences in AUC were respectively: -0.10 (95% confidence interval [CI] [-0.13-(-0.06)], p<0.0001), -0.14 (95% CI [-0.19-(-0.09)], p<0.0001) and -0.03 (95% CI [-0.05-(-0.001)], p<0.02). M2-PK was inferior to FC in discriminating patients with mild UC from those with HS (AUC difference -0.23, 95% CI [-0.31-(-0.15)], p<0.0001).
  
  
  CONCLUSIONS
  FC reflects pediatric IBD severity and activity better than M2-PK. This difference is particularly pronounced when identifying patients with mild UC and UC in remission.
authors.affiliation: Child & Mother Specialist Hospital in Poznan, Poznań, Poland.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Czub
authors.affiliation: Poznan University of Medical Sciences, Department of Pediatric Gastroenterology & Metabolic Diseases, Poznań, Poland.
authors.forename: Jan K
authors.initials: JK
authors.lastname: Nowak
authors.affiliation: Nicolaus Copernicus University, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Department of Pediatric Endoscopy and Gastrointestinal Function Testing, Bydgoszcz, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Szaflarska-Poplawska
authors.affiliation: Medical University of Silesia, Department of Paediatrics, Katowice, Poland.
authors.forename: Urszula
authors.initials: U
authors.lastname: Grzybowska-Chlebowczyk
authors.affiliation: Medical University of Gdansk, Department of Pediatrics, Pediatric Gastroenterology, Hepatology and Nutrition, Gdańsk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Landowski
authors.affiliation: Poznan University of Medical Sciences, Department of Informatics and Statistics, Poznań, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Moczko
authors.affiliation: Poznan University of Medical Sciences, Poznań, Poland.
authors.forename: Daria
authors.initials: D
authors.lastname: Adamczak
authors.affiliation: Poznan University of Medical Sciences, Department of Paediatric Surgery, Traumatology and Urology, Poznań, Poland.
authors.forename: Przemyslaw
authors.initials: P
authors.lastname: Mankowski
authors.affiliation: Poznan University of Medical Sciences, Department of General, Gastroenterological and Endocrinological Surgery, Poznań, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Banasiewicz
authors.affiliation: Institute of Human Genetics, Polish Academy of Sciences, Poznań, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Plawski
authors.affiliation: Poznan University of Medical Sciences, Department of Pediatric Gastroenterology & Metabolic Diseases, Poznań, Poland.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Walkowiak
mesh_terms: D000293:Adolescent; D015415:Biomarkers; D002648:Child; D005243:Feces / Q000201:enzymology*; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000201:enzymology / Q000473:pathology*; D039841:Leukocyte L1 Antigen Complex / Q000096:biosynthesis*; D008297:Male; D010372:Pediatrics; D020033:Protein Isoforms / Q000096:biosynthesis; D011770:Pyruvate Kinase / Q000096:biosynthesis*
chemical_list: D015415:Biomarkers; D039841:Leukocyte L1 Antigen Complex; D020033:Protein Isoforms; D011770:Pyruvate Kinase