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.
