Similarity in the metabolic profile in macroscopically involved and un-involved colonic mucosa in patients with inflammatory bowel disease: an in vitro proton ((1)H) MR spectroscopy study.
BACKGROUND
The histological extent of inflammatory bowel disease (IBD) is greater than that evident by colonoscopic evaluation. We hypothesized that metabolic profile in macroscopically un-involved colonic mucosa in IBD is similar to that of controls with healthy colon. We thus assessed the differences in metabolic profile in macroscopically involved and un-involved colonic mucosa of IBD patients to further substantiate the extent of disease.


METHODS
Colonic mucosal biopsies were obtained and snap frozen from both the macroscopically un-involved and involved colonic mucosa of IBD patients and macroscopically normal colonic mucosa of controls and were subjected to in-vitro high-resolution proton ((1)H) magnetic resonance (MR) spectroscopy and the concentrations of metabolites were determined.


RESULTS
Thirty-two metabolites were assigned in the proton MR spectrum of colonic mucosa of IBD patients. The concentrations of amino acids (isoleucine, leucine, valine, arginine, lysine, glutamine/glutamate, alanine), membrane metabolites (choline, glycerophosphorylcholine/phosphorylcholine), glycolytic product (lactate) and short chain fatty acid (formate) were significantly lower while significantly high level of glucose were observed in the macroscopically un-involved colonic mucosa of IBD patients compared to the macroscopically normal mucosa of controls. There was no significant difference in the concentrations of metabolites in macroscopically involved and un-involved colonic mucosa of IBD patients.


CONCLUSIONS
The metabolic profile in macroscopically un-involved colonic mucosa of IBD patients is similar to that of macroscopically involved mucosa but different from colonic mucosa of controls. This suggests that even macroscopically un-involved colonic mucosa is metabolically abnormal and may explain the increase in extent of disease with time.
Sharma
Uma
U
Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India.
Singh
Rajiv R
RR
Ahuja
Vineet
V
Makharia
Govind K
GK
Jagannathan
Naranamangalam R
NR
D000328:Adult; D015415:Biomarkers / Q000378:metabolism*; D001704:Biopolymers / Q000378:metabolism*; D003106:Colon / Q000378:metabolism*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons
D015415:Biomarkers; D001704:Biopolymers; D011522:Protons