Presepsin teardown - pitfalls of biomarkers in the diagnosis and prognosis of bacterial infection in cirrhosis

AIM: To evaluate the diagnostic and prognostic value of presepsin in cirrhosis-associated bacterial infections. METHODS: Two hundred and sixteen patients with cirrhosis were enrolled. At admission, the presence of bacterial infections and level of plasma presepsin, serum C-reactive protein (CRP) and procalcitonin (PCT) were evaluated. Patients were followed for three months to assess the possible association between presepsin level and short-term mortality. RESULTS: Present 34.7 of patients had bacterial infection. Presepsin levels were significantly higher in patients with infection than without (median, 1002 pg/mL vs 477 pg/mL, P < 0.001), increasing with the severity of infection [organ failure (OF): Yes vs No, 2358 pg/mL vs 710 pg/mL, P < 0.001]. Diagnostic accuracy of presepsin for severe infections was similar to PCT and superior to CRP (AUC-ROC: 0.85, 0.85 and 0.66, respectively, P = NS for presepsin vs PCT and P < 0.01 for presepsin vs CRP). At the optimal cut-off value of presepsin > 1206 pg/mL sensitivity, specificity, positive predictive values and negative predictive values were as follows: 87.5%, 74.5%, 61.8% and 92.7%. The accuracy of presepsin, however, decreased in advanced stage of the disease or in the presence of renal failure, most probably because of the significantly elevated presepsin levels in non-infected patients. 28-d mortality rate was higher among patients with > 1277 pg/mL compared to those with ≤ 1277 pg/mL (46.9% vs 11.6%, P < 0.001). In a binary logistic regression analysis, however, only PCT (OR = 1.81, 95%CI: 1.09-3.01, P = 0.022) but neither presepsin nor CRP were independent risk factor for 28-d mortality after adjusting with MELD score and leukocyte count. CONCLUSION: Presepsin is a valuable new biomarker for defining severe infections in cirrhosis, proving same efficacy as PCT. However, it is not a useful marker of short-term mortality.