Fecal intestinal inflammatory biomarkers in piglets: analytical validation, homogeneity and stability studies

Analytical validation of biomarker assays as indicators of intestinal inflammatory processes is essential for the diagnosis, prognosis and monitoring of intestinal health. In the context of porcine intestinal health, feces are a sample of choice for determining inflammatory molecules released into the intestinal contents in pathological conditions. The advantage of this method is that it is non-invasive and samples can be collected easily, quickly and without causing stress. In this study, we validated the analytical procedures for measuring lipocalin-2 (LCN-2), myeloperoxidase (MPO) and adenosine deaminase (ADA) in porcine fecal samples. Validation was carried out by studying precision (intra- and inter-assay coefficients of variation), linearity under dilution, recovery, and the limits of detection and quantification. All three biomarkers fulfilled the required validation parameters. Furthermore, we analyzed the distribution of the three compounds and calprotectin (fCal) in the stools and found that all of them except LCN-2 were homogeneously distributed in the fecal sample. The stability of the compounds under different storage temperatures was assessed, and fCal was found to be the most stable parameter overall.