Can serum calprotectin be a reliable biomarker in dogs with gastrointestinal symptoms?

Calprotectin is a protein involved in the inclusion of inflammatory cells in the body's immune response by interacting with endothelial cells. Measured in serum it is used as a prognostic factor for dogs with sepsis and systemic inflammatory response syndrome (SIRS). Many studies showed promising results using fecal calprotectin in diagnosing inflammatory bowel disease. The aim of this study was to determine if serum calprotectin can be a reliable biomarker in dogs with gastrointestinal symptoms (GS). The dogs enrolled in this study were patients admitted at the Veterinary Hospital. Inclusion criteria for healthy dogs (control group, n=5) were: absence of signs of inflammation or infection seen in clinical examination, complete blood count and biochemistry. Animals assigned to the gastrointestinal group (GI group, n=8) had GS (vomiting and diarrhoea). Serum samples were taken from all the dogs. Serum concentrations of canine calprotectin (cCP) were determined with sandwich enzyme immunoassay for in vitro quantitative measurement of canine calprotectin concentration (AbClonal technology, Woburn, Massachusetts, United States). All samples were measured in duplicates and their mean value was taken for statistical analysis. The highest cCP concentration was 328.2 μg/L and the lowest 18.1 μg/L. According to study done by Heilmann (2012) the reference range of calprotectin in serum is 76.4 to 563.6 μg/L. The median of serum cCP in the control group was 105.4 μg/L and in GI group 115.7 μg/L, both values were within reference range. There were no differences in calprotectin concentrations between the control and GI groups. Based on this preliminary study it can be concluded that serum calprotectin can’t be used as a reliable biomarker in dogs with gastrointestinal symptoms.