To explore the predictive value of combined detection of serum regenerated islet derived protein 3α (Reg3α), procalcitonin (PCT), and clinical factors for postoperative pancreatitis (PEP) in patients with common bile duct stones after endoscopic retrograde cholangiopancreatography (ERCP).

A total of 200 patients with common bile duct stones who received ERCP treatment in Sichuan Second Hospital of Traditional Chinese Medicine from January 2022 to January 2025 were selected retrospectively as the research subjects. They were divided into the PEP group (32 cases) and the non-PEP group (168 cases) according to whether PEP occurred after the operation. The clinical data and the levels of serum Reg3α and PCT between the two groups were compared. Spearman was used to analyze the correlation between serum Reg3α and PCT levels and PEP. Multivariate Logistic regression was used to screen for independent risk factors of PEP. The receiver operating characteristic (ROC) curve was drawn to evaluate the individual and combined predictive value of each index.

There were statistically significant differences in the history of previous pancreatitis, serum amylase level (AMY), serum lipase (LPS), size of common bile duct stones and operation time between the PEP group and the non-PEP group (P<0.05). The levels of serum Reg3α and PCT in the PEP group were both higher than those in the non-PEP group (P<0.001). Spearman showed that both serum Reg3α and PCT levels were positively correlated with the occurrence of PEP (r=0.426, P<0.001; r=0.361, P<0.001). Binary Logistic regression showed that AMY, the size of common bile duct stones, serum Reg3α, serum PCT and previous history of pancreatitis were independent risk factors for PEP after ERCP in patients with common bile duct stones (P<0.05). ROC showed that the AUC of serum Reg3α, PCT and other single indicators for predicting PEP was 0.604-0.872, while the AUC of the combined prediction model was significantly increased to 0.987 (with a sensitivity of 0.938 and a specificity of 0.946). Moreover, the DeLong test showed that the combined predictive efficacy was significantly superior to any single indicator (P<0.05).

The combined detection of preoperative serum Reg3α, PCT and clinical factors has a high clinical predictive value for PEP in patients with common bile duct stones after ERCP, and its combined predictive efficiency is significantly better than that of single index detection, which is helpful for early identification of patients with high risk of PEP.