CD3+ T-Lymphocytic Coeliac-Mesenteric Ganglioneuritis Associated with Colonic Torsion and Inflammatory Bowel Disease in an Arabian Broodmare.

This research article outlines an account of the first-ever reported case of CD3 T-lymphocytic extramural enteric ganglioneuritis, a type of immune response, in an Arabian broodmare suffering from an inflammatory bowel disease corresponding to colonic torsion and acute colic.

Background and Case Presentation

• A 5-year-old Arabian broodmare exhibiting acute colic symptoms was examined in the study.
• In the absence of identifiable pathogens through aerobic culture or histopathological examination, the mare was diagnosed with lymphocytic ganglioneuritis of the coeliac-mesenteric ganglia along with a lymphocytic-plasmacytic enterocolitis condition similar to inflammatory bowel disease (IBD) in humans.

Findings and Interpretation

• The ganglia (nerve cell clusters) of the mare were found to be infiltrated multifocally by small lymphocytes (white blood cells), which were immunopositive for CD3, a marker for mature T cells, and negative for CD20 and CD79a antigens, markers for B cells. This suggested that the ganglioneuritis, inflammation of the nerve ganglia, was mediated by CD3 T-lymphocytes.
• These results suggested the presence of immune-mediated IBD, leading to a disturbance in the autonomic nervous system of the horse’s gastrointestinal tract, a condition seen in human patients with ulcerative colitis.

Comparison and Significance

• The histopathological manifestations in the broodmare differed notably from those of equine enteric dysautonomia and chronic intestinal pseudo-obstruction, two conditions that are characterized by neuronal degeneration and inflammation, respectively, and primarily impact the mural ganglion plexuses (networks of nerves in the digestive tract).
• The importance of this study lies in the fact that it is the first reported appearance of CD3 T-lymphocytic extramural enteric ganglioneuritis, i.e., inflammation of the ganglia in the extramural enteric (intestinal) region facilitated by T-lymphocytes, in equine inflammatory bowel disease. This provides invaluable information for further research into IBD in horses.