MORPHOMETRIC EVALUATION OF IMMUNOGLOBULIN A-CONTAINING AND IMMUNOGLOBULIN G-CONTAINING CELLS AND T-CELLS IN DUODENAL MUCOSA FROM HEALTHY DOGS AND FROM DOGS WITH INFLAMMATORY BOWEL-DISEASE OR NONSPECIFIC GASTROENTERITIS

Objective-To investigate the distribution of IgA- and IgG-containing c ells and T cells in the villi of duodenal mucosa from healthy dogs and from dogs with inflammatory bowel disease (IBD) or gastroenteritis. D esign-Case-control study. Animals-28 dogs, grouped according to clinic al and histologic criteria: 11 dogs with IBD, 8 dogs with nonspecific gastroenteritis, and 9 healthy dogs. Procedure-Endoscopic biopsy speci mens of duodenal mucosa from each dog were stained specifically for Ig A and IgG heavy chains and pan T-cell (CD3) antigen, using immunoperox idase techniques. Morphometric analysis, performed via an image-analys is system, was used to count IgA- and IgG-containing cells and T cells within paired contiguous villi from each dog. Results-T cells were th e predominant immune cell type in all groups of dogs. Significant diff erences in the villus distribution of IgA- and IgG-containing cells an d T cells were not observed. Healthy dogs had significantly higher T-c ell counts than had dogs with IBD or gastroenteritis. Dogs with nonspe cific gastroenteritis had a significantly higher concentration of IgA- containing cells than the other groups of dogs had. Significant group differences for IgG-containing cells also were evident, with dogs with IBD having the lowest cell counts. Conclusions and Clinical Relevance -High concentrations of IgA- and IgG-containing cells and T cells in t he villus lamina propria cannot be reliably used to distinguish IBD fr om other intestinal disorders in dogs. Evaluation of T cells may be th e most discriminatory method for differentiating dogs with IBD from cl inically normal dogs via examination of intestinal biopsy specimens.