BackgroundDietary hypersensitivity and inflammatory bowel disease (IBD) are important causes of chronic vomiting and diarrhea in cats. IL-23 has been recently found to be a key factor in the immunopathogenesis of IBD in humans but the involvement in IBD has not been investigated in cats.
Hypothesis/ObjectivesExpression of genes encoding Il-12p35 and p40, IL-23p19, and IFN- may be up-regulated in duodenal biopsy specimens taken from cats with histologic evidence of inflammation.
Animals and MethodsDuodenal biopsy specimens were collected from control cats (n=21) and cats with inflammatory enteropathy (n=13). Routine histopathology, immunohistochemistry (IHC), and qRT-PCR were used to assess expression of MHC class II and to measure gene transcripts encoding the p35, p40, and p19 subunits of the IL-12 family of cytokines and IFN-.
ResultsThere were significant differences in expression of mRNA encoding IL-12p35 and IL-23p19 between healthy cats and cats with inflammatory enteropathy. IL-12p35 mRNA was lower in the duodenal mucosa of cats with inflammatory enteropathy compared with the mucosa of healthy cats (P=.001). In contrast, IL-23p19 mRNA expression was higher in duodenal biopsy specimens from cats with inflammatory enteropathy than in those from healthy controls (P=.001). There was no difference in expression of IL-12p40 and IFN- mRNA (P>.05). The majority of cats with inflammatory enteropathy had histologic evidence of moderate to severe colitis (score 2).
Conclusions and Clinical ImportanceThe results of this preliminary study suggest that IL-23 plays a role in the pathogenesis of feline inflammatory enteropathy.
- Dietary hypersensitivity
- Food-responsive diarrhea
- Inflammatory bowel disease
- IMMUNE CELL-POPULATIONS