Association of platelet-lymphocyte ratio with acute pancreatitis severity: systematic review and meta-analysis

Acute pancreatitis (AP) is an inflammatory disease with a heterogeneous clinical course, ranging from mild symptoms to life-threatening complications. The platelet-to-lymphocyte ratio (PLR), an easily accessible inflammatory biomarker, has shown prognostic value in other conditions but has been understudied in AP. This review aimed to systematically evaluate the association between PLR and AP severity. A PRISMA-guided systematic review and meta-analysis was conducted, searching PubMed, Web of Science, Scopus, and WHO-VHL databases (earliest records to March 2025). Observational studies reporting PLR and AP severity were included. Pooled standardized mean differences (SMDs) were calculated using a random-effects model. Among 20 included studies encompassing 5,920 patients, PLR was significantly higher in severe acute pancreatitis (SAP) versus non-SAP (SMD = 1.137, 95% CI: 0.752–1.702, P < .001). Subgroup analysis by SAP definition revealed significant differences (p = .011). In studies using the Revised Atlanta classification, PLR was markedly higher in SAP patients (SMD = 1.479, 95% CI: 0.729 to 2.231). The Egger’s regression test and funnel plot indicated no significant publication bias (p = .105) and the sensitivity analysis confirmed robustness of the findings. PLR may serve as a low-cost biomarker for AP severity stratification, with higher levels indicating severe disease and poor outcomes. Its integration into clinical practice could enhance early risk assessment, particularly in resource-limited settings. Prospective studies are needed to validate optimal cutoff values and refine its prognostic utility.