Changes in S100A8/A9 and S100A12 and Their Comparison with Other Analytes in the Saliva of Pigs with Diarrhea Due to E. coli

SIMPLE SUMMARY: S100A8/A9 (also known as calprotectin) and S100A12 (also known as calgranulin C) are considered biomarkers of potential interest and are proteins members of the calgranulin family which is related to different inflammatory conditions, immune-mediated diseases, and sepsis. The objectives of this study were to evaluate if S100A8/A9 and A12 could change in the saliva of pigs with diarrhea due to E. coli and compare the changes of S100A8/A9 and A12 with other analytes in order to explore the possible causes or mechanisms involved in these changes. For this purpose, a panel integrated by other analytes related to inflammation, immune system, stress, tissue damage, sepsis, and redox status was also evaluated. S100A8/A9 and S100A12 increased in pigs with diarrhea produced by E. coli and were correlated with other salivary analytes. Further studies should be performed to elucidate the possible practical applications of these calgranulins as biomarkers to evaluate the health and welfare of pigs. ABSTRACT: The family of calgranulins includes S100A8 (calgranulin A), S100A9 (calgranulin B), which can appear as a heterodimer known as S100A8/A9 or calprotectin, and S100A12 (calgranulin C). These proteins are related to different inflammatory conditions, immune-mediated diseases, and sepsis and are considered biomarkers of potential interest. This study aims to evaluate if S100A8/A9 and A12 could change in pigs with diarrhea due to E. coli and to compare the changes of S100A8/A9 and A12 with other analytes in order to explore the possible causes or mechanisms involved. For this purpose, a panel integrated by analytes related to inflammation (haptoglobin, inter-alpha trypsin inhibitor 4 (ITIH4), and total protein); immune system (adenosine deaminase, ADA); stress (alpha-amylase); tissue damage (lactate and lactate dehydrogenase (LDH)); sepsis (aldolase) and redox status (ferric-reducing ability of saliva (FRAS) and advanced oxidation protein products (AOPP)) was evaluated. S100A8/A9 and A12 and the other analytes measured in this study showed increases in the saliva of pigs with diarrhea due to E. coli. S100A8/A9 and/or A12 showed a significant correlation of different magnitude with some of the other analytes evaluated. Further studies should be conducted to gain knowledge about the possible practical applications as biomarkers of the measurements of S100A8/A9 and A12 in the saliva of pigs.