title: IgG4-Seronegative Autoimmune Pancreatitis and Sclerosing Cholangitis.
abstract: IgG4-related disease is a relatively novel clinical entity whose gastrointestinal manifestations include type 1 autoimmune pancreatitis (AIP) and IgG4-associated sclerosing cholangitis. The presence of elevated serum IgG4 is suggestive but not essential for the diagnosis of type 1 AIP and is a pervasive feature of the proposed diagnostic criteria. The differential diagnosis of type 1 AIP includes malignant conditions, emphasizing the importance of a deliberate, comprehensive evaluation. Management of patients with a suggestive clinical presentation, but without serum IgG4 elevation, is difficult. Here we present three cases of IgG4-seronegative AIP and sclerosing cholangitis that responded to empiric steroid therapy and discuss approach considerations. These cases demonstrate the value of meticulous application of existing diagnostic algorithms to achieve a clinical diagnosis and avoid surgical intervention.
authors.affiliation: Department of Medicine, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Allon
authors.initials: A
authors.lastname: Kahn
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Anitha D
authors.initials: AD
authors.lastname: Yadav
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: M Edwyn
authors.initials: ME
authors.lastname: Harrison