Septic arthritis (SA) in horses poses lasting health challenges. Successful recovery depends largely on initiating prompt and intensive therapy that often extends over a long duration. Current diagnostic techniques are inadequate for reliably confirming the full elimination of joint infection. Identifying and characterizing mRNA biomarkers could offer a more accurate alternative. This investigation aimed to pinpoint mRNA biomarkers that indicate the successful clearance of joint infection in equine SA and to compare these findings with previously reported proteomic data. Furthermore, the transcriptomic data were assessed against the human SeptiCyte Lab mRNA panel, which distinguishes sepsis from non-septic shock. A comparative transcriptomic analysis was carried out on synovial fluid from the SA joints of five horses during active infection and after post-treatment clearance, along with five horses exhibiting non-septic synovitis. Eight novel mRNA transcripts were found to be significantly upregulated (>3-fold) in horses with active SA relative to those after infection resolution and those with non-septic inflammation. Two corresponding proteins from the proteomic dataset aligned with these transcripts but were not statistically distinct. The human SeptiCyte transcripts were not differentially expressed in this study. These outcomes suggest that mRNA expression could serve as a promising indicator for infection resolution in equine joints and merits additional study.
