Serum Calprotectin Expression as a Diagnostic Marker for Sepsis in Postoperative Intensive Care Unit Patients

The research was performed to explore the diagnosis value of dynamic serum calprotectin (SC) expression for sepsis in postoperative intensive care unit patients. One hundred sixty-three patients who met the inclusion criteria served as the study group. All cases in the study group were further divided into the sepsis subgroup (51 cases) and the nonsepsis subgroup (112 cases). Fifty healthy volunteers served as the control group. The levels of SC and other laboratory indexes including complete blood counts, leukocytes, the immature-to-total-neutrophil ratio, procalcitonin (PCT), C-reactive protein, and blood lactate were detected, cytokines [interleukin (IL)-2, IL-6, and interferon-γ] released by neutrophils were also determined. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score and the Sequential Organ Failure Assessment score were calculated. The factors related to prognosis were analyzed with multivariate logistic regression analysis. The diagnostic accuracies of ΔSC [the differences of SC levels between postoperative day (POD) 1 and POD 2, 3, 5, 7] and ΔPCT (the differences of PCT levels between POD 1 and POD 2, 3, 5, 7) on sepsis were compared with other markers for sepsis. The levels of SC and cytokines were markedly increased on POD 1, 2, 3, 5, and 7 in the study group compared with the control group (P < 0.05 or P < 0.01). The same results were found in the sepsis subgroup compared with the nonsepsis subgroup (P < 0.05 or P < 0.01). Significant positive correlations between SC and cytokines were confirmed in patients of the study group (P < 0.05 or P < 0.01). APACHE II scores and the levels of SC and PCT on POD 1 were the variables significantly associated with sepsis. The diagnostic accuracies of ΔSC_1-3 (sensitivity 87%, specificity 89%) and ΔPCT_1-3 (sensitivity 89%, specificity 90%) for sepsis were greater than other ΔSCs and ΔPCTs. It appears that the dynamic changes in SC are of the predictive values for septic patients after major surgeries.