The clinical utility of immunoglobulin G4 in the evaluation of autoimmune pancreatitis and pancreatic adenocarcinoma.

Published

Journal Article

BACKGROUND: Elevation in the serum immunoglobulin-G4 (IgG4) level has been used as a diagnostic marker to distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC), but its true utility is ill-defined. This study evaluates the clinical utility of IgG4 in differentiating AIP from PDAC. METHODS: All patients evaluated in the hepatopancreaticobiliary surgery clinics with measured serum IgG4 were included. Patients were divided into normal IgG4 (<135 mg/dL) and elevated IgG4 (≥135 mg/dL) groups. The final diagnosis was determined by operative pathology when available or by clinical outcome. The sensitivity, specificity, PPV, and NPV of IgG4 for diagnosing AIP was assessed. RESULTS: Between 1997 and 2015, 298 patients were identified. Normal IgG4 levels were present in 85% of patients (254/298), while 15% (44/298) were elevated. The overall prevalence of AIP was 17% (52/298). The sensitivity and specificity of IgG4 for AIP was 67% and 96%, respectively; however, the PPV was only 80%, including a 9% occurrence of PDAC in patients with an elevated IgG4. CONCLUSION: In this study of selected patients who underwent IgG4 testing, 9% of elevated IgG4 patients had PDAC. The overreliance on IgG4 as diagnostic for AIP may lead to mis-diagnosis and delayed treatment for PDAC.

Full Text

Duke Authors

Cited Authors

  • Pak, LM; Schattner, MA; Balachandran, V; D'Angelica, MI; DeMatteo, RP; Kingham, TP; Jarnagin, WR; Allen, PJ

Published Date

  • February 2018

Published In

Volume / Issue

  • 20 / 2

Start / End Page

  • 182 - 187

PubMed ID

  • 29033025

Pubmed Central ID

  • 29033025

Electronic International Standard Serial Number (EISSN)

  • 1477-2574

Digital Object Identifier (DOI)

  • 10.1016/j.hpb.2017.09.001

Language

  • eng

Conference Location

  • England