Detection of Anti-Erythrocyte Antibodies in Dogs with Inflammatory Bowel Disease (IBD)

SIMPLE SUMMARY: In human patients with intestinal inflammation, many other diseases may occur due to it, but their presence in dogs is rarely described. The aim of the study was to prove if antibodies against red blood cells (RBC) were present in dogs with chronic intestinal inflammation (IBD), as it is demonstrated for humans, and to described other RBC abnormalities. IBD was diagnosed using the current consensus and a disease severity score was assessed for each dog, as well as score from endoscopy and intestinal histology. Our results showed that most of dogs had antibodies against RBC and 50% of dogs showed RBC regeneration in addition to chronic inflammation hematologic findings. In IBD dogs, the presence of anti-RBC antibodies and the other RBC alterations may suggest a subclinical RBC damaged (hemolysis). ABSTRACT: Several extra-intestinal manifestations, including immune-mediated cytopenias, are reported in human inflammatory bowel disease (IBD), whereas they are poorly documented in dogs. Hypothesizing that immune-mediated subclinical anemia can occur in canine IBD, the study aim was to evaluate the erythrogram and the presence of anti-RBC antibodies in dogs with IBD. IBD was diagnosed according to the following criteria: chronic gastrointestinal signs, ruling out of extra-intestinal diseases, no improvement with diet trial, histological evidence of inflammatory infiltration, and improvement after immunosuppressant therapy. Canine Chronic Enteropathy Clinical Activity Index (CCECAI) endoscopic and histopathological scores were assessed for each dog. Twenty-five dogs were enrolled, and each dog had a CBC evaluation prior to endoscopy. The CBC was performed using laser hematology analyzer and blood smears were carefully reviewed for the presence of nucleated RBC, anisocytosis, polychromasia, and Howell–Jolly bodies. IgG and IgM anti-RBC antibodies were evaluated with flow cytometry. A high frequency of positive cases for anti-RBC antibodies in dogs with IBD (17/25 dogs) was ascertained. Approximatively 50% of dogs showed some hematologic features of RBC regeneration in addition to hematologic findings consistent with chronic inflammation. Anti-RBC antibodies and signs of erythroid regeneration may suggest possible subclinical chronic immune-mediated hemolysis that can cause anemia in dogs with IBD, together with the chronic inflammation.