Evaluation of procalcitonin (PCT), neutrophilic gelatinase-associated lipocalin (NGAL), interleukins 1ß and 6 as biomarkers for sepsis and endotoxemia in equine colic

Introduction Former studies have shown a misbalance of elastinolytic activity in the peritoneal cavity in association with sepsis scoring and equine colic. In this study, we evaluated the correlation of neutrophilic gelatinase-associated lipocalin (NGAL) and procalcitonin (PCT), a well-established sepsis marker in human medicine, as well as associated interleukins (IL) 1ß and 6 in plasma and peritoneal fluid to clinical sepsis scoring and survival of equine colic patients.

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 used to classify 51 horses presented with colic and 4 control horses as negative (n=30, ≤6/19 points), questionable (n=14, 7-9/19 points) or positive (n=11, ≥10/19 points) for sepsis. PCT, NGAL and IL-1ß and 6 concentrations were evaluated in plasma and peritoneal fluid (PF) using species-specific sandwich ELISA kits (MyBiosource). The discriminatory power of the single factors contributing to sepsis scoring and survival were investigated using linear discriminant analysis.

Results Hematocrit and lactate in plasma were positively associated with overall sepsis scoring, in PF lactate (positive association, P=0.001) and IL-6 (negative association, P=0.006) were associated significantly with sepsis scoring. Clinical scoring, lactate levels in plasma and clinical scoring, total protein and lactate in PF influenced survival (P<0.05). Lactate was found the best biomarker in PF, indicating 93.3% of euthanized and 77.3% of survivors correctly at a cut-off of 2.85 mmol/L. Unfortunately, PCT and NGAL correlated with neither sepsis scoring nor survival.

Conclusion In conclusion, the well-established biomarker lactate remained the best in our study. New biomarkers evaluated in this study including NGAL, PCT, interleukins 1ß and IL-6 did not show a significant diagnostic or prognostic value concerning the severity of endotoxemia and survival of horses presented with clinical signs of colic.

Publication History

Article published online:
06 May 2022