2018 ACVIM Forum Research Abstract Program: Seattle, Washington, June 14 - 15, 2018

Localization of S100A12 positive cells and Helicobacter organisms was studied using paraffin-embedded gastric biopsies, 11 from dogs with chronic gastritis and 9 from healthy control dogs (5 of these were obtained post-mortem after the patient had presented to the emergency service at the Veterinary Teaching Hospital at Texas A&M University, none of which had gross or histopathological lesions suggesting gastrointestinal disease and 4 were research dogs from Universidad de Caldas). No dog had received antibiotic or corticosteroid treatment in the last two weeks prior to the collection of gastric biopsies. IHC was performed using antibodies directed against canine S100A12 (cS100A12) and Helicobacter spp., respectively. cS100A12 staining in the lamina propria was quantified and classified into absent, mild, moderate, or severe and Helicobacter density was graded using similar criteria. Histopathological evaluation was conducted following the World Small Animal Veterinary Association (WSAVA) grading scheme. Spearman';s rank correlation was used to evaluate any possible associations between cS100A12 with Helicobacter density and histopathology findings. A Mann-Whitney U test was used to compare ordinal variables between healthy and sick dogs. Immunoglobulin (Ig)-binding to gut bacteria likely activates immune responses locally and systemically however it has never been investigated in dog IBD yet. Therefore, our study investigated whether the humoral immune response against commensal gut bacteria in IBD is greater than that of healthy dogs. Additionally, whether the Ig-binding bacteria potentially triggers an exacerbated immune response that aggravates gut homeostasis.