MMP-9 Concentration in Peritoneal Fluid Is a Valuable Biomarker Associated with Endotoxemia in Equine Colic
Ann Kristin Barton1, Ina-Gabriele Richter2, Tanja Ahrens1
1Equine Clinic, Freie Universitaet Berlin, Berlin, Germany.
Abstract:
The purpose of the study was to compare the results of sepsis scoring (clinical examination and clinical pathology) to the concentrations of matrix-metalloproteinases (MMPs) -2, -8, and -9; tissue-inhibitor of metalloproteinases (TIMPs) -1 and -2; and inflammatory chemokines interleukin (IL) 1β and tumor-necrosis-factor-alpha (TNF-α) in plasma and peritoneal fluid of equine colic patients. A modified sepsis scoring including general condition, heart and respiratory rate, rectal temperature, mucous membranes, white blood cell count (WBC), and ionized calcium was applied in 47 horses presented with clinical signs of colic. Using this scoring system, 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. MMPs, TIMPs, IL-1β, and TNF-α concentrations were evaluated in plasma and peritoneal fluid using species-specific sandwich ELISA kits. In a linear discriminant analysis, all parameters of sepsis scoring apart from calcium separated well between sepsis severity groups (P < 0.05). MMP-9 was the only biomarker of high diagnostic value, while all others remained insignificant. A significant influence of overall sepsis scoring on MMP-9 was found for peritoneal fluid (P = 0.005) with a regression coefficient of 0.092, while no association was found for plasma (P = 0.085). Using a MMP-9 concentration of >113 ng/ml in the peritoneal fluid was found to be the ideal cutoff to identify positive sepsis scoring (≥10/19 points; sensitivity of 83.3% and specificity of 82.9%). In conclusion, MMP-9 was found to be a biomarker of high diagnostic value for sepsis and endotoxemia in equine colic. The evaluation of peritoneal fluid seems preferable in comparison to plasma. 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 therapeutic intervention.
Insights
Matrix-metalloproteinase-9 (MMP-9) in peritoneal fluid effectively identifies sepsis in horses with colic. A concentration over 113 ng/ml indicates a high likelihood of sepsis, aiding rapid diagnosis.
Area of Science:
- Veterinary Internal Medicine
- Equine Critical Care
- Biomarker Discovery
Background:
- Sepsis is a life-threatening condition in horses, often associated with colic.
- Accurate and timely diagnosis of sepsis is crucial for effective treatment.
- Current diagnostic methods for equine sepsis can be time-consuming.
Purpose of the Study:
- To compare clinical sepsis scoring with plasma and peritoneal fluid concentrations of specific biomarkers.
- To evaluate matrix-metalloproteinases (MMPs), tissue-inhibitors of metalloproteinases (TIMPs), and inflammatory chemokines (IL-1β, TNF-α) as potential sepsis indicators in equine colic.
- To determine the diagnostic value of these biomarkers, particularly MMP-9, for sepsis in horses.
Main Methods:
- A modified sepsis scoring system was applied to 47 horses with colic, assessing clinical and clinicopathological parameters.
- Concentrations of MMPs (-2, -8, -9), TIMPs (-1, -2), IL-1β, and TNF-α were measured in plasma and peritoneal fluid using ELISA.
- Linear discriminant analysis was used to assess the diagnostic value of biomarkers and their correlation with sepsis scores.
Main Results:
- MMP-9 was the only biomarker with significant diagnostic value for sepsis severity in equine colic patients.
- Peritoneal fluid MMP-9 concentrations showed a significant positive correlation with the overall sepsis score (P = 0.005).
- A peritoneal fluid MMP-9 cutoff of >113 ng/ml demonstrated high sensitivity (83.3%) and specificity (82.9%) for identifying sepsis.
Conclusions:
- MMP-9 is a valuable biomarker for diagnosing sepsis and endotoxemia in equine colic cases.
- Peritoneal fluid analysis for MMP-9 is superior to plasma analysis for sepsis detection in these patients.
- A rapid pen-side assay for MMP-9 in peritoneal fluid could significantly aid clinical decision-making for equine colic.
