Serum Procalcitonin for the Diagnosis of Spontaneous Bacterial Peritonitis in Patients With Decompensated Cirrhosis: A Prospective Study

Objectives: Spontaneous bacterial peritonitis (SBP) is a serious infectious complication in patients with decompensated cirrhosis. Although serum procalcitonin (PCT) has been evaluated as a potential indicator of bacterial infection, its clinical value in the diagnosis of SBP remains uncertain. This study investigated the diagnostic contribution of serum procalcitonin in cirrhotic patients with SBP.
Methods: This prospective, single-center study included 100 participants: 50 patients with SBP, 25 patients with sterile ascites, and 25 healthy controls. The diagnosis of SBP was established according to the ascitic fluid polymorphonuclear leukocyte (PMNL) count and/or positive ascitic fluid culture findings. Serum procalcitonin levels and ascitic inflammatory parameters were compared among the study groups.
Results: Serum procalcitonin levels were numerically higher in patients with SBP than in patients with sterile ascites and healthy controls; however, the differences were not statistically significant (p>0.05). In contrast, ascitic fluid leukocyte and PMNL counts were significantly elevated in the SBP group (p<0.05). No significant association was observed between serum procalcitonin concentrations and the Child–Turcotte–Pugh classification.
Conclusion: Serum procalcitonin alone showed limited diagnostic performance in distinguishing spontaneous bacterial peritonitis in patients with decompensated cirrhosis. Ascitic fluid inflammatory parameters, particularly the PMNL count, remained more informative for diagnostic evaluation.

Keywords: Ascites, biomarker, liver cirrhosis, procalcitonin, spontaneous bacterial peritonitis