Plasma Concentrations of Intestinal Fatty Acid Binding Protein, Vasoactive Intestinal Polypeptide, C-Reactive Protein and Interleukin-6 in Vomiting Dogs with and without Foreign Body Induced Gastrointestinal Obstruction
C. Parratt; R. Harrand; E. Moody; A. Boag; A. Firth
Introduction: Foreign body induced gastrointestinal obstructions (FBO) can be difficult to diagnose.
Background: Plasma vasoactive intestinal polypeptide (VIP) concentrations increase in canine experimental bowel obstruction, and concentrations of intestinal fatty acid binding protein (I-FABP) increase in humans with ischemic bowel obstruction.
Objective: To investigate plasma concentrations of VIP and I-FABP in dogs with and without FBO. C-reactive protein (CRP) and interleukin-6 (IL-6) were also measured as markers of the acute phase response.
Methods: Dogs were eligible for inclusion if they had vomited at least once in the preceding 24 hours, and if an FBO could not be excluded at presentation. Dogs that received corticosteroids or were less than 5.0 kg or 3 months old were excluded. Dogs were categorised as FBO positive (FBO+) or negative (FBO-) based upon surgical findings, or follow up with owners or their veterinarian. The study was approved by the RCVS ethics review panel.
Sample size estimation was 101 dogs. Wilcoxon-Mann-Whitney test and receiver operator curves (ROC) were applied to investigate the diagnostic potential of each peptide. p<0.05 was considered significant.
Results: Overall, 112 dogs were recruited. Ten were excluded. The remaining 102 dogs were used for analysis (FBO- n=85, FBO+ n=17). There was no difference in gender, age or bodyweight between groups. FBO+ dogs had significantly greater concentrations of I-FABP than FBO- dogs (median 1.90 ng/ml vs. 0.61 ng/ml (p=0.018). No statistically significant difference was identified in VIP, CRP or IL-6 (p>0.05). ROC area under curve (AUC) for I-FABP was 0.74 (95%CI 0.61–0.868). Using an I-FABP cut-off of 0.35 ng/ml, sensitivity and specificity were 94.1% and 35.3%, and at 8.52 ng/ml were 11.8% and 95.3%.
Discussion: I-FABP concentrations in excess of 8.52 ng/ml are strongly suggestive of FBO, whilst concentrations less than 0.35 ng/ml mean that an FBO is unlikely.
Conclusion: This is the first study to demonstrate that plasma I-FABP concentrations are increased in vomiting dogs with FBO. Specific I-FABP cut-offs were determined, which could contribute to a diagnosis in a proportion of cases. Further studies are required to fully explore its clinical utility.