Evaluation of Some Potential New Serological and Faecal Markers in Canine Lymphangiectasia: Correlation with Mucosal Morphology and Histological Score

Intestinal lymphangiectasia (IL) and protein-losing enteropathy are frequently associated. This condition, relatively common in dogs, is often associated with diseases such as inflammatory bowel disease (IBD), intestinal lymphoma or right-sided heart failure. It is diagnosed by typical features on upper intestinal endoscopy confirmed with duodenal mucosal biopsies and serological alterations such as hypoalbuminaemia, hypocholesterolaemia and hypocobalaminaemia. Massive pleural or abdominal fluid collection, thromboembolism and hypocalcaemia or hypomagnesaemia are variably associated. The aims of this study were to evaluate new and early serological/faecal markers for this condition. We evaluated, in a group of 16 IL-affected dogs, serological levels of albumin, cholesterol, C-reactive protein (CRP), bacterial lipopolysaccharide (LPS), cleaved cytokeratin 18 (cCK18), citrulline and zonulin; the latter was also evaluated in faeces. Resulting data were compared with those obtained from a population of seven healthy dogs and with histopathological score of intestinal mucosa (HS), morphometrical data regarding villi (villous height, width, height/width ratio) and CIBDAI score. Histomorphological data, serological concentration of albumin (P <0.0001), cholesterol (P <0.0001), CRP (P = 0.0029), LPS (P = 0.0001), cCK18 (P = 0.0001) and faecal concentration of zonulin (P <0.0001) were able to discriminate IL-affected from healthy control dogs. Serological values of zonulin (P = 0.6898) and citrulline (P = 0.0693) showed no differences. The present study shows interesting perspectives for serum bacterial LPS and cCK18 and for faecal zonulin evaluations in discriminating healthy dogs from IL.