부산대학교 도서관

Background and Aim: Acute pancreatitis (AP) remains the most common gastroenterological reason for hospital admission, with most cases attributable to gallstone disease or excessive alcohol intake. Autoimmune pancreatitis (AIP) is a rare cause of AP, accounting for 3.9% of all suspected pancreatitis. Serum immunoglobulin G fraction 4 (IgG4) can be used as a screening test for type 1 AIP, although an elevated IgG4 level in isolation does not meet diagnostic criteria of AIP as proposed by the Mayo Clinic (criteria: elevated IgG4 level and characteristic imaging or diagnostic histology or response to steroid therapy). A large meta-analysis showed that serum IgG4 has a high specificity and relatively low sensitivity for diagnosing AIP; however, this cohort was predominantly patients with chronic pancreatitis, and only a small proportion (3.5%) had AP. To date, no studies have examined the diagnostic yield of IgG4 in first-presentation AP. We aimed to determine the diagnostic utility of routine serum IgG4 screening for diagnosing AIP in patients presenting with their first episode of AP. Method(s): All patients presenting with AP and admitted under the gastroenterology unit at two metropolitan tertiary hospitals were prospectively recorded over 24 months from September 2016 to August 2018. Patients presenting with first-episode AP in whom serum IgG4 was tested were included. An elevated IgG4 level was defined as > 0.86 g/L. The primary outcome was confirmed AIP meeting Mayo Clinic diagnostic criteria. A limited cost analysis of IgG4 testing was performed. Result(s): Of 533 patients with first-presentation AP, 218 had IgG4 levels tested and were included for analysis. The median patient age was 55 years (IQR, 41-69) and 46% were male. The median Bedside Index of Severity in Acute Pancreatitis (BISAP) score was 1 (IQR, 0-1). The most common causes of AP were idiopathic (n = 82), gallstone related (n = 72), and alcohol induced (n = 38). Median length of stay was 5 days, and