摘要Background:Infected pancreatic necrosis(IPN)is a highly morbid local complication following necrotizing pancreatitis.Early enteral nutrition has been proven to be effective in preventing IPN.This study aimed to assess the association between the trajectory of prealbumin(PAB)during the early phase of acute pancreatitis(AP)and the incidence of IPN and other clinical outcomes.Methods:This retrospective,dual-centered study screened patients with AP admitted to the Center of Acute Pancreatitis,Jinling Hospital and the Affiliated Hospital of Zunyi Medical University from January 2018 to December 2022.The PAB levels during the first week after admission were collected.The primary outcome was the incidence of IPN within 90 days after AP onset.Group-based trajectory modelling was performed to describe the trajectory of PAB levels over time.A Cox proportional hazard model was used to facilitate the interpretation of the time-varying hazard ratio(HR)between PAB and outcomes.Fine-Gray sub-distribution hazard model was adopted for sensitivity analysis.Results:A total of 373 patients were included,of whom 82(22.0％)were diagnosed with IPN within 90 days.The trajectory model assigned 232 patients to the low-level PAB(L-PAB)group and 141 to the high-level PAB(H-PAB)group.The incidence of 90-day IPN in the L-PAB group was significantly higher than that in the H-PAB group(26.7％vs.14.2％,P=0.005).The multivariate Cox regression model showed that a high PAB trajectory was associated with a lower incidence of IPN(HR=0.52,95％CI:0.30-0.89;P=0.017)after adjustment for potential confounders.In the sensitivity analysis,taking death as a com-peting risk,high PAB trajectory remained significantly associated with a lower incidence of IPN in the Fine-Gray model(HR=0.55,95％CI:0.33-0.92;P=0.022).Conclusions:A high PAB trajectory within the first week of AP was significantly associated with a lower incidence of IPN within 90 days after AP onset.Dynamic monitoring of PAB levels in the early phase of AP may play an important role in stratifying patients at high risk of developing IPN.