Colonic nitrite and immunoglobulin G concentrations in dogs with inflammatory bowel disease.
OBJECTIVE
To evaluate lavage analytes as markers of mucosal inflammation in healthy dogs and dogs with inflammatory bowel disease (IBD).


METHODS
Case control study.


METHODS
9 healthy dogs and 10 dogs with IBD.


METHODS
A polyethylene glycol electrolyte solution was administered into the dogs colons via a rectal balloon catheter prior to colonoscopy. Lavage solution was allowed to remain intraluminally for 30 minutes and then was withdrawn. Lavage supernatant samples were immediately analyzed for total protein, IgG, and nitrite concentrations and myeloperoxidase activity. Mucosal biopsy specimens were obtained from the descending colon and histologically reviewed.


RESULTS
All dogs with IBD had mild to severe lymphocytic-plasmacytic colitis, whereas 8 of 9 healthy dogs did not have substantial mucosal inflammation. Myeloperoxidase activity was not detected in lavage samples from healthy dogs or dogs with IBD. Total protein concentration was not significantly different between groups. Mean nitrite and IgG concentrations were significantly higher in samples from dogs with IBD (1.83 nmol/ml and 46 mg/dl, respectively), compared with samples from healthy dogs (0.245 nmol/ml and undetectable concentrations, respectively). Severity of lesions was not correlated with nitrite or IgG concentration.


CONCLUSIONS
Assay of nitrite and IgG concentrations in colonic lavage fluid is a simple, objective means of evaluating mucosal inflammation in dogs with IBD. Potential uses include monitoring response to treatment and evaluation of complex cases of chronic intestinal inflammation.
Gunawardana
S C
SC
Department of Veterinary Physiology, College of Veterinary Medicine, Iowa State University, Ames 50011, USA.
Jergens
A E
AE
Ahrens
F A
FA
Niyo
Y
Y
D000704:Analysis of Variance; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D003106:Colon / Q000737:chemistry* / Q000276:immunology / Q000473:pathology; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D005260:Female; D007074:Immunoglobulin G / Q000032:analysis* / Q000378:metabolism; D015212:Inflammatory Bowel Diseases / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D007413:Intestinal Mucosa / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D008297:Male; D009573:Nitrites / Q000032:analysis* / Q000378:metabolism; D009195:Peroxidase / Q000032:analysis / Q000378:metabolism; D011092:Polyethylene Glycols; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D012720:Severity of Illness Index; D007507:Therapeutic Irrigation / Q000379:methods / Q000662:veterinary
D015415:Biomarkers; D007074:Immunoglobulin G; D009573:Nitrites; D011506:Proteins; D011092:Polyethylene Glycols; D009195:Peroxidase