Changes in Calprotectin (S100A8-A9) and Aldolase in the Saliva of Horses with Equine Gastric Ulcer Syndrome

Abstract

Equine gastric ulcer syndrome (EGUS) is a highly prevalent disease that affects horses worldwide. Within EGUS, two different forms have been described: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD). The associated clinical signs cause detrimental activity performance, reducing the quality of life of animals. Saliva can contain biomarkers for EGUS that could be potentially used as a complementary tool for diagnosis. The objective of this work was to evaluate the measurements of calprotectin (CALP) and aldolase in the saliva of horses as potential biomarkers of EGUS. For this purpose, automated assays for the quantification of these two proteins were analytically validated and applied for detecting EGUS in a total of 131 horses divided into 5 groups: healthy horses, ESGD, EGGD, combined ESGD and EGGD, and horses with other intestinal pathologies. The assays showed good precision and accuracy in analytical validation, and they were able to discriminate between horses with EGUS and healthy horses, especially in the case of CALP, although they did not show significant differences between horses with EGUS and horses with other diseases. In conclusion, salivary CALP and aldolase can be determined in the saliva of horses and further studies are warranted to elucidate the potential of these analytes as biomarkers in EGUS.

Automated Spectrophotometric Assays for the Measurement of Ammonia and Bicarbonate in Saliva of Horses: Analytical Validation and Changes in Equine Gastric Ulcer Syndrome (EGUS)

“…As mentioned earlier, saliva samples were gathered from all horses prior to intravenous sedation, and gastroscopy was conducted immediately after the horses were positioned in the examination stand [ 18 , 23 ]. Saliva was collected using a sponge, which was then placed into a Salivette tube.…”

Measurement of Trace Elements (Zinc, Copper, Magnesium, and Iron) in the Saliva of Horses: Validation Data and Changes in Equine Gastric Ulcer Syndrome (EGUS)

“…A thorough clinical assessment was conducted on all horses, encompassing a detailed medical history, a physical examination (which encompassed weight assessment, body condition score (BCS) measured on a nine-point scale [ 23 ], evaluation of heart and respiratory rates, rectal temperature, color of mucous membranes, capillary refill time, and borborygmus), along with hematological and biochemical analyses. Following a 16 h fasting period, gastroscopy was performed on all subjects in accordance with previously outlined protocols [ 24 ]. For the identification of EGSD and EGGD, the images obtained with gastroscopy were interpreted by only one person from each hospital, both with more than ten years of experience, according to the guidelines by the European College of Equine Internal Medicine (ECEIM) indicated in its Consensus Statement [ 23 , 24 ].…”

“…Following a 16 h fasting period, gastroscopy was performed on all subjects in accordance with previously outlined protocols [ 24 ]. For the identification of EGSD and EGGD, the images obtained with gastroscopy were interpreted by only one person from each hospital, both with more than ten years of experience, according to the guidelines by the European College of Equine Internal Medicine (ECEIM) indicated in its Consensus Statement [ 23 , 24 ]. A horse was considered to have ESGD if it had a score higher than 1 when evaluated with the grading scale of ESGD created by the ECEIM Consensus, which goes from 0 to 4 points.…”

S-100 Proteins: Basics and Applications as Biomarkers in Animals with Special Focus on Calgranulins (S100A8, A9, and A12)

“…In animals, species-specific assays have been used in different species such as dogs for the measurement of S100A8/A9 [ 102 ] and S100A12 [ 118 ] and cats for S100A12 [ 119 ]. In addition, a human turbidimetric immunoassay has been validated for the measurement of calprotectin in the saliva of pigs [ 120 ] and horses [ 121 ], and also in feces of dogs and cats [ 122 ] and pigs [ 123 ]. Therefore, there is the possibility of using heterologous immunoassays for the measurement of calprotectin, as used for other analytes such as acute phase proteins [ 124 ], providing the necessary analytical validation has been undertaken.…”

“…Calprotectin expression in the colon was also increased in a case of colon inflammation after black walnut extract administration, which is associated with a systemic inflammatory response [ 151 ]. In equine saliva, calprotectin had a higher concentration in horses with equine gastric ulcer syndrome (EGUS) compared with healthy horses, although the concentration did not allow differentiation of horses with EGUS from horses with similar clinical signs due to other gastrointestinal causes [ 121 ].…”