Serum trypsin as an early predictor of post‐endoscopic retrograde cholangiopancreatography pancreatitis

Abstract Background Serum amylase (AMY) levels measured 2–6 h after ERCP are a predictor of post‐ERCP pancreatitis (PEP). Trypsin is one of the pancreatic enzymes elevated in the development of PEP. The study assessed whether serum trypsin (TRY) can predict early‐stage PEP. Methods This prospective study included patients who underwent ERCP from June 2022 to May 2023. TRY, AMY, serum pancreatic AMY (P‐AMY), and serum lipase (LIP) levels were measured immediately after ERCP and 2 h later. The primary outcome was the diagnostic abilities of TRY levels measured immediately (0 h‐TRY) and 2 h after (2 h‐TRY) ERCP to predict PEP (compared with the other serum pancreatic enzymes). Results Of 130 patients analyzed, 18 developed PEP. The sensitivity and specificity of 0 h‐TRY were 83.3% and 69.6%, respectively, and those of 2 h‐TRY were 88.9% and 72.3%, respectively. The area under the curve (AUC) for 0 h‐TRY was significantly higher than that for 0 h‐AMY ( p = .006) and 0 h‐P‐AMY ( p = .012), whereas the AUCs for 0 h‐TRY and 0 h‐LIP did not differ significantly ( p = .563). The AUC for 2 h‐TRY for predicting PEP was significantly higher than that for 2 h‐AMY ( p = .025), whereas there was no significant differences between the AUCs for 2 h‐TRY and 2 h‐P‐AMY( p = .146), or between those for 2 h‐TRY and 2 h‐LIP ( p = .792). The median increase ratio (expressed as a ratio relative to baseline) in TRY was highest among all of serum pancreatic enzymes tested immediately after ERCP (5.35, 1.72, 1.94, and 4.44 for TRY, AMY, P‐AMY, and LIP, respectively). Conclusion Measuring TRY immediately after ERCP is useful for the early prediction of PEP.