Evaluation of matrix-metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) as biomarkers for sepsis and endotoxemia in equine colic

Objective In this study, we evaluated elastinolytic and collagenolytic matrix-metalloproteinases (MMP-2, -8 and -9) and their tissue inhibitors (TIMP-1 and -2) in plasma and peritoneal fluid of equine colic patients and correlated them to clinical sepsis scoring.

Material and methods A modified sepsis scoring including general condition, heart and respiratory rate, inner body temperature, mucous membranes, white blood count and ionized calcium was performed in 47 horses presented with colic. Horses were classified as negative (n = 32, ≤ 6/19 points), questionable (n = 9, 7–9/19 points) or positive (n = 6, ≥ 10/19 points) for sepsis. MMP and TIMP concentrations were evaluated in plasma and peritoneal fluid using species-specific sandwich ELISA kits.

Results In a linear discriminant analysis, all parameters of sepsis scoring apart from calcium separated well between severity groups (p < 0.05). A significant influence of overall sepsis scoring on MMP-9 was found for peritoneal fluid (p = 0.007) with a regression coefficient of 0.131, while no significant association was found for plasma (p = 0.078). A MMP-9 concentration of > 113 ng/ml in peritoneal fluid was found to be the ideal cut-off to identify positive sepsis scoring (≥ 10/15 points; sensitivity of 85.7 % and specificity of 87.5 %). No significant correlations were found between sepsis scoring and MMP-2, MMP-8, TIMP-1 and TIMP-2 (p > 0.05), indicating no increase in collagenolytic activity or overwhelming fibrosis formation.

Conclusion MMP-9 in peritoneal fluid was found to be a biomarker of high diagnostic value for sepsis and endotoxemia in acute equine colic. As abdominocentesis is commonly performed in the diagnostic work-up of equine colic, a pen-side assay would be useful and easy-to perform diagnostic support in the decision for surgery and prognostic estimation. The evaluation of TIMP concentrations may be more rewarding in the postoperative phase, possibly indicating adhesion or fibrosis formation. This remains to be studied in the future.

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Artikel online veröffentlicht:
26. April 2021