GI15 - Evaluation of a Commercial Serologic Panel Marketed for the Diagnosis of Chronic Enteropathy in Dogs

Abstract: Background: It has been suggested that a panel of IgA-based serologic assays aids in the diagnosis of chronic enteropathy (CE) in dogs, a syndrome which includes conditions such as food-responsive enteropathy, immunosuppressant responsive enteropathy, and inflammatory bowel disease (also referred to as chronic inflammatory enteropathy). However, it is unclear whether these markers discriminate between CE and other types of primary intestinal disorders.
Objectives: To evaluate a commercially available diagnostic panel that measures serum levels of IgA directed against OmpC (ACA), canine calprotectin (ACNA), and gliadin-derived peptides (AGA) in dogs with well-characterized intestinal diseases.
Animals: 32 dogs with primary intestinal disease.
Methods: Serum ACA, ACNA, and AGA levels were measured in dogs with CE and dogs with other forms of primary intestinal disease (non-CE population), including bacterial, fungal, parasitic, and neoplastic enteropathies. Serum IgA levels were compared between populations, and sensitivities and specificities were calculated using laboratory-provided cut-points.
Results: Twelve of 15 (80.0%) CE dogs and 14 of 17 (82.4%) non-CE dogs had abnormally high levels of at least 2 markers; these proportions were not significantly different (P = 0.99). A serum ACA level ≥ 15 EU/mL was 80.0% sensitive for CE, but specificity was only 29.4%.
Conclusions and Clinical Importance: The serologic panel was moderately sensitive, but poorly specific for a CE diagnosis. Common treatments for CE, such as dietary modifications and immunosuppressants, might delay appropriate therapy or even be detrimental for many of the patients with non-CE diseases that commonly showed high ACA, ACNA, and AGA levels.