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

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.