IgG4-associated cholangitis

We report a young female patient with IgG4-associated cholangitis (IAC) who presented with common bile duct (CBD) stricture and review the features that distinguish IAC from both primary sclerosing cholangitis (PSC) and other types of secondary sclerosing cholangitis (SSC). IAC is a biliary manifestation of IgG4-related sclerosing disease, an autoimmune condition characterized by elevated serum IgG4 and infiltrates containing lymphocytes and IgG4-positive plasma cells, accompanied by sclerosis. On endoscopic retrograde cholangiopancreatography, IAC consists of segmental biliary strictures with a predilection for the distal CBD, whereas in PSC the strictures are more band-like; other types of SSC often demonstrate unifocal ductal obstructions, sometimes associated with choleliths. On histologic examination, the bile duct wall in IAC contains a denser lymphocytic infiltrate and sparser sclerosis than in PSC; other types of SSC can be distinguished histologically by the types of inflammatory cells present. Unlike those of PSC, IAC-related strictures are reversible with corticosteroids.