Urine trypsinogen-2 as a noninvasive screening test for predicting post-ERCP pancreatitis (PEP)

Abstract

Background and Objectives: post endoscopic retrograde cholangiopancreatography pancreatitis (post-ERCP) pancreatitis (PEP) is a notorious complication of ERCP procedure with varying incidence and severity across literature. There is a dearth of screening modalities which can accurately predict PEP in the immediate postprocedure period. The objective of our study was to assess the reliability of a rapid urine trypsinogen-2 dipstick test in predicting PEP at 4 h post-ERCP. Methods: This was a prospective, single center, analytical study conducted over a period of eighteen months among 124 patients who underwent ERCP for various biliary indications at SRM Institute for Medical Sciences Hospital, Chennai. Patients with acute or chronic pancreatitis and those undergoing any form of pancreatic endotherapy were specifically excluded. Urine samples were collected at 4 h postprocedure and tested for trypsinogen-2 using a commercially available, rapid urine dipstick test with a lower limit of detection of 50 mg/L. Patients were subsequently followed up for a day and assessed clinically and biochemically for the development of PEP. Results: After excluding 57 patients out of the 124 as per the exclusion criteria, a total of 79 patients who underwent ERCP for various biliary indications were ultimately enrolled for the study and subsequent analysis. Three out of the seventy nine patients in the study population were diagnosed to have PEP (3.79%) and one out of the three patients developed severe acute PEP. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of urine trypsinogen-2 at 4 h post-ERCP as a predictor of PEP were 66.7%, 92.1%, 25%, 98.3% and 91.1%, respectively. Serum lipase levels were elevated more than or equal to three times upper limit of normal in a total of eleven patients (11/79). 8/11 patients had asymptomatic hyperlipasemia. Median serum lipase level in patients with PEP was 864 U/L. Conclusion: Urine trypsinogen 2 dipstick can be reliably used as a screening test in ruling out PEP and guiding clinicians in discharging patients on the day of ERCP procedure. However, larger, blinded studies with lesser logistic limitations are needed to provide further evidence to extrapolate our data and advocate the utilization of this test in routine practice.