IgG4-Seronegative Autoimmune Pancreatitis and Sclerosing Cholangitis

Immunoglobulin G4-Seronegative Autoimmune Cholangiopathy With Pancreatic and Hepatic Involvement Mimicking as Primary Sclerosing Cholangitis

Immunoglobulin G4-seronegative autoimmune cholangiopathy is a rare cause of biliary strictures. We describe a 27-year-old man presenting with elevated liver enzymes, recurrent cholangitis/bacteremia, biliary strictures, and normal immunoglobulin G4 levels, who was initially diagnosed with primary sclerosing cholangitis, and later listed for transplantation for recurrent bacteremia. Subsequent surveillance imaging demonstrated morphologic changes consistent with biliary strictures and autoimmune pancreatitis. Initiating corticosteroids resulted in liver enzyme normalization and stricture improvement. Diagnosing seronegative autoimmune cholangiopathy remains challenging given similar presentation to primary sclerosing cholangitis. This case highlights importance of a wide differential for biliary strictures, with increased suspicion in those developing pancreatic changes in this setting.

IgG4-related disease: a complex under-diagnosed clinical entity

IgG4-related disease (IgG4-RD) encompasses a spectrum of complex fibro-inflammatory disorders which are often under diagnosed due to unfamiliarity by clinicians. A challenging multitude of clinical manifestations makes the diagnosis cumbersome. The primary clinical feature in IgG4-RD entails a tumor-like presentation coupled with tissue-destructive lesions. Histopathological findings include lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis. These findings, in combination with elevated serum immunoglobulin G4 levels, are diagnostic in the setting of single- or multi-organ involvement. A closer understanding of the role of T cells and B cells in the increased production of IgG4 has led to a notion that IgG4 can act as a pathogen, anti-inflammatory agent, or rheumatoid factor. Glucocorticoids are the primary treatment modality; however, relapse is common with prolonged therapy. Alternatively, immunomodulatory agents are being increasingly used as therapy. The aim of this article is to raise awareness of IgG4-RD and review the diagnostic algorithm, as IgG4-RD often mimics a wide array of clinical conditions. In addition, we summarize the pathogenesis and current treatment guidelines of IgG4-RD for clinicians. Awareness and accurate diagnosis are crucial in preventing progression to chronic diseases, thereby diminishing disease-related morbidity and mortality.