Background: Recent studies have confirmed that calprotectin is a marker helpful in the diagnosis of sepsis, and have suggested that it may also be helpful in predicting prognosis. We investigated the prognostic value of calprotectin by comparing it with presepsin, procalcitonin and CRP in patients with sepsis.

Methods: This study is a prospective observational study and is currently ongoing at a 20-bed medical ICU in a university-affiliated hospital in Seoul, Korea from Dec 2022 to Jan 2024. Septic patients based on the Sepsis-3 definitions were enrolled who were admitted to the ICU through the emergency room(ER). We had a serial measurement of calprotectin, presepsin, procalcitonin and CRP : 1) at the time of ER visit (day 1), 2) at 48-72 hour after the first sampling (day 3), and 3) at 72-120 (day 7) hour after the second sampling.

Results: A total of 67 sepsis patients were included. The median age was 79 [72-84], 56% were female, and 35 (52%) patients had septic shock. Initial SOFA score was 5 [4-7]. Bacterial pneumonia (52%) was the most common cause of sepsis. The hospital mortality was 23.9%. In a ROC curve analysis, at day 1 and 3, calprotectin was the most powerful predictor for hospital mortality (AUC=0.793, 95% CI [0.646-0.939], p=0.008 (D1) and 0.867 [0.710-1.000], p=0.001 (D3)) compared with presepsin, procalcitonin and CRP. On the other hand, at day 7, calprotectin was still remained as a significant predictor (0.837 [0.700-0.974], p=0.002), but, presepsin is most powerful (0.893 [0.767-1.000], p < 0.001).

Conclusion: Our results suggests that calprotectin has a strong prognostic power in sepsis at the early stage of hospital admission.