Value of serum procalcitonin levels in predicting spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis (SBP) is a life-threatening disease that poses a great diagnostic challenge to clinicians. We aimed to systemically and quantitatively summarize the current evidence on the diagnostic value of the procalcitonin (PCT) test in identifying SBP.

We searched EMBASE, MEDLINE, the Cochrane database and reference lists of relevant articles with no language restrictions through May 2012. We selected original research that reported the diagnostic performance of PCT alone or compared with other biomarkers to diagnose SBP. We summarized test performance characteristics using forest plots, summary receiver operating characteristic curves and bivariate random effects models.

We found only three qualifying studies examining 181 episodes of suspected infection with 50 (27.6%) confirmed SBP episodes from 3 countries. Bivariate pooled sensitivity, specificity, positive likelihood ratios and negative likelihood ratios were 86% (95%CI: 73%-94%), 80% (95%CI: 72%-87%), 7.73 (95%CI: 0.91-65.64) and 0.14 (95%CI: 0.01-1.89), respectively. The global measures of accuracy, area under the receiver operating curve (AUROC) and diagnostic odds ratio (DOR), showed PCT has excellent discriminative capability and individual study showed serum PCT testing has better accuracy than ascitic PCT, serum CRP or IL-6 testing. There was evidence of significant heterogeneity but no evidence of publication bias.

The existing literature suggests moderate to high accuracy for PCT as a diagnostic aid for SBP. However, larger, appropriately designed prospective studies are needed to conclusively address the value of serum PCT testing in SBP diagnosis.