Evaluation of plasma Procalcitonin concentrations in healthy foals and foals affected by septic Systemic Inflammatory Response Syndrome

The aim of this work was to evaluate procalcitonin concentrations in healthy foals and in foals with septic Systemic Inflammatory Response Syndrome (SIRS). Plasma procalcitonin (PCT) concentrations were evaluated in 51 foals and SIRS scale was calculated. Foals were divided into control group (no septic SIRS criteria met) and septic SIRS group (SIRS score ≥ 2 plus evidence of sepsis or localized infection). PCT concentrations were evaluated with a commercial ELISA kit. The data were expressed as mean and standard deviation. A T-test was performed between healthy and septic SIRS groups. A ROC curve was carried out. Finally, correlation analysis between PCT concentration and SIRS scale was performed by using Pearson test. The PCT concentrations in control and septic SIRS groups were 30.0±33.1 and 178.9±76.0 pg/ml, respectively. The T-test showed differences between control group and septic SIRS group (p<0.0001). A positive linear correlation between PCT concentration and SIRS scale was observed (r=0.73, r2=0.53, p<0.0001). The ROC curve was statistically significant (p<0.0001) and the best cut-off value to determine septic SIRS was 73.04 pg/ml (87.5% sensitivity, 97.1% specificity and a likelihood ratio of 30.6). Overall, the results showed an increase in plasma PCT concentrations in septic SIRS foals. A cut-off between control and septic SIRS groups was obtained.