Purpose Infected pancreatic necrosis (IPN) is a highly morbid complication of acute necrotising pancreatitis (ANP). Since there is evidence of early-onset immunosuppression in acute pancreatitis, immune enhancement may be a therapeutic option. This trial aimed to evaluate whether early immune-enhancing Thymosin alpha 1 (Tα1) treatment reduces the incidence of IPN in patients with predicted severe ANP. Methods We conducted a multicentre, double-blind, randomised, placebo-controlled trial involving ANP patients with an Acute Physiology and Chronic Health Evaluation II (APACHE II) score ≥ 8 and a computed tomography (CT) severity score ≥ 5 admitted within 7 days of the advent of symptoms. Enrolled patients were assigned to receive a subcutaneous injection of Tα1 1.6 mg every 12 h for the first 7 days and 1.6 mg once a day for the subsequent 7 days or matching placebos (normal saline). The primary outcome was the development of IPN during the index admission. Results A total of 508 patients were randomised, of whom 254 were assigned to receive Tα1 and 254 placebo. The vast majority of the participants required admission to the intensive care unit (ICU) (479/508, 94.3%). During the index admission, 40/254(15.7%) patients in the Tα1 group developed IPN compared with 46/254 patients (18.1%) in the placebo group (difference -2.4% [95% CI − 7.4 to 5.1%]; p = 0.48). The results were similar across four predefined subgroups. There was no difference in other major complications, including new-onset organ failure (10.6% vs. 15%), bleeding (6.3% vs. 3.5%), and gastrointestinal fistula (2% vs. 2.4%). Conclusion The immune-enhancing Tα1 treatment of patients with predicted severe ANP did not reduce the incidence of IPN during the index admission. Supplementary Information The online version contains supplementary material available at 10.1007/s00134-022-06745-7.

Background There were bacteria in the early pancreatic juice culture of severe acute pancreatitis (SAP) patients, but during the clinical time, some patients showed more positive bacteria and some patients showed more negative bacteria. Many scholars have different test results, and further clinical research needs to be carried out to clarify this fact. To determine evidence of infection in the early stage of acute pancreatitis (AP) by pancreatic juice bacterial culture and provide a reference for the anti-infective therapy of AP. Methods Patients with AP who underwent pancreatic juice bacterial culture in the Department of hepatobiliary surgery of the General Hospital of Ningxia Medical University from January 1, 2019 to June 30, 2020were reviewed. Endoscopic retrograde cholangiopancreatography (ERCP) was used to collect pancreatic juice, which was sent to the laboratory for culturing. The clinical data and bacterial culture results of the patients were then recorded and analyzed. According to the results of the pancreatic juice culture, the patients were divided into a positive bacterial culture group (n=64) and a negative bacterial culture group (n=92). It was compared the data results of two groups [age, gender, etiology, acute physiology and chronic health evaluation (APACHE) II score, cultured bacteria, complications, local complications, Balthazar computed tomography (CT) score, inflammatory factors, the use of antibiotics, drug sensitivity analysis results, and the patient’s co-infection] and performed multivariate analysis to identify the clinically valuable indicators. Moreover, a receiver operating characteristic (ROC) curve was drawn to predict the model of positive pancreatic juice culture in AP. Results The patients in the positive bacterial culture group and the negative bacterial culture group had statistically significant differences in gender, age, body mass index (BMI), amylase, white blood cell count and the two groups of patients were comparable. A total of 156 patients were included in the study and pathogenic bacteria were cultured in the pancreatic juice of 64 patients (41.03%) and 94 strains of bacteria were found (Gram-positive bacteria, 38.30%; Gram-negative bacteria, 58.51%; fungi, 3.19%). A history of ERCP and early pancreatic necrosis were independent influencing factors of positive pancreatic juice culture. The incidence of complications, APACHE II, and inflammatory factor levels of patients with positive pancreatic juice bacterial culture were significantly higher than those of negative pancreatic juice bacterial culture (P<0.05). Multivariate regression and the ROC curve of pancreatic infection showed that positive pancreatic and Balthazar CT score >7 on admission were independent risk factors of pancreatic. The area under the ROC curve of patients with later pancreatic infection was 0.863 [95% confidence interval (CI): 0.769–0.957], specificity was 65.30%, sensitivity was 90.50%, and the Youden index was...