Clinical Significance of Low-Density Granulocytes in Acute Pancreatitis.

Background: Low-density granulocytes (LDGs), a unique subset of neutrophils, have been shown in previous studies to exhibit distinct biological functions in immune-inflammatory diseases. However, their role in acute pancreatitis (AP) remains unclear. Objective: To investigate the association between peripheral blood LDGs levels and clinical severity in patients with AP. Methods: This cross-sectional study analyzed peripheral LDGs levels in 41 mild AP (MAP) patients, 40 moderate-to-severe AP (SAP) patients, and 41 healthy controls (HC). LDGs were measured within 24 h of admission. Statistical analysis, including Kruskal-Wallis tests and logistic regression, assessed LDGs' association with clinical characteristics and AP severity. Results: LDGs levels were significantly higher in moderate-to-SAP compared to MAP and HC (p < 0.001). Elevated LDGs levels correlated positively with white blood cell count (WBC), glucose (GLU), neutrophil-to-lymphocyte ratio, Acute Physiology and Chronic Health Evaluation II (APACHE II), and Bedside Index for Severity in Acute Pancreatitis (BISAP) scores (p < 0.05). Logistic regression identified LDGs as an independent risk factor for moderate-to-SAP. Receiver operating characteristic (ROC) analysis revealed high predictive accuracy, the area under the curve (AUC = 0.967) at a 2.96% cutoff, with 95.0% sensitivity and 90.2% specificity. The follow-up indicated that patients with LDGs > 2.96% had a higher risk of recurrence. Conclusion: Elevated peripheral LDGs levels in AP patients are associated with disease activity.