How to diagnose IgG4-related disease

We read with great interest the editorial by Fox and Fox1 describing the use of serum immunoglobulin G4 (IgG4) concentrations as a marker for IgG4-related disease (IgG4-RD). IgG4-RD is a fascinating clinical entity including a wide variety of diseases, formerly diagnosed as Mikulicz’s disease, autoimmune pancreatitis (AIP), interstitial nephritis, prostatitis and retroperitoneal fibrosis.2 ,3 However, universal criteria for IgG4-RD have not yet...