title: Serum and urine metabolomic fingerprinting in diagnostics of inflammatory bowel diseases.
abstract: OBJECTIVE
  To evaluate the utility of serum and urine metabolomic analysis in diagnosing and monitoring of inflammatory bowel diseases (IBD).
  
  
  METHODS
  Serum and urine samples were collected from 24 patients with ulcerative colitis (UC), 19 patients with the Crohn's disease (CD) and 17 healthy controls. The activity of UC was assessed with the Simple Clinical Colitis Activity Index, while the activity of CD was determined using the Harvey-Bradshaw Index. The analysis of serum and urine samples was performed using proton nuclear magnetic resonance (NMR) spectroscopy. All spectra were exported to Matlab for preprocessing which resulted in two data matrixes for serum and urine. Prior to the chemometric analysis, both data sets were unit variance scaled. The differences in metabolite fingerprints were assessed using partial least-squares-discriminant analysis (PLS-DA). Receiver operating characteristic curves and area under curves were used to evaluate the quality and prediction performance of the obtained PLS-DA models. Metabolites responsible for separation in models were tested using STATISTICA 10 with the Mann-Whitney-Wilcoxon test and the Student's t test (α = 0.05).
  
  
  RESULTS
  The comparison between the group of patients with active IBD and the group with IBD in remission provided good PLS-DA models (P value 0.002 for serum and 0.003 for urine). The metabolites that allowed to distinguish these groups were: N-acetylated compounds and phenylalanine (up-regulated in serum), low-density lipoproteins and very low-density lipoproteins (decreased in serum) as well as glycine (increased in urine) and acetoacetate (decreased in urine). The significant differences in metabolomic profiles were also found between the group of patients with active IBD and healthy control subjects providing the PLS-DA models with a very good separation (P value < 0.001 for serum and 0.003 for urine). The metabolites that were found to be the strongest biomarkers included in this case: leucine, isoleucine, 3-hydroxybutyric acid, N-acetylated compounds, acetoacetate, glycine, phenylalanine and lactate (increased in serum), creatine, dimethyl sulfone, histidine, choline and its derivatives (decreased in serum), as well as citrate, hippurate, trigonelline, taurine, succinate and 2-hydroxyisobutyrate (decreased in urine). No clear separation in PLS-DA models was found between CD and UC patients based on the analysis of serum and urine samples, although one metabolite (formate) in univariate statistical analysis was significantly lower in serum of patients with active CD, and two metabolites (alanine and N-acetylated compounds) were significantly higher in serum of patients with CD when comparing jointly patients in the remission and active phase of the diseases. Contrary to the results obtained from the serum samples, the analysis of urine samples allowed to distinguish patients with IBD in remission from healthy control subjects. The metabolites of importance included in this case up-regulated acetoacetate and down-regulated citrate, hippurate, taurine, succinate, glycine, alanine and formate.
  
  
  CONCLUSIONS
  NMR-based metabolomic fingerprinting of serum and urine has the potential to be a useful tool in distinguishing patients with active IBD from those in remission.
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Dawiskiba
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Stanisław
authors.initials: S
authors.lastname: Deja
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Mulak
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Ząbek
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Jawień
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Pawełka
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Banasik
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Mastalerz-Migas
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Waldemar
authors.initials: W
authors.lastname: Balcerzak
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Kaliszewski
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Skóra
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Barć
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Korta
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Kornel
authors.initials: K
authors.lastname: Pormańczuk
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Przemyslaw
authors.initials: P
authors.lastname: Szyber
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Litarski
authors.affiliation: Tomasz Dawiskiba, Jan Skóra, Piotr Barć, Krzysztof Korta, Kornel Pormańczuk, Przemyslaw Szyber, Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, 50-556 Wroclaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Młynarz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000097:blood / Q000175:diagnosis* / Q000628:therapy / Q000652:urine; D003424:Crohn Disease / Q000097:blood / Q000175:diagnosis* / Q000628:therapy / Q000652:urine; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D055432:Metabolomics / Q000379:methods; D008875:Middle Aged; D011044:Poland; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012074:Remission Induction; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Crohn's disease; Inflammatory bowel disease; Metabolomics; Partial least-squares-discriminant analysis; Proton nuclear magnetic resonance spectroscopy; Serum; Ulcerative colitis; Urine