IgG4-associated sclerosing cholangitis: a diagnosis that may change the course of events (review of the literature and a clinical case)

Immunoglobulin G4-associated sclerosing cholangitis (IgG4-SC) can mimic primary sclerosing cholangitis, cholangiocarcinoma, and pancreatic adenocarcinoma. Its proper diagnosis allows for an adequate therapy and an improvement of the outcomes. The article presents a short literature review with an emphasis on the challenging diagnostic and therapeutic aspects, illustrated by a clinical case. The diagnosis of IgG4-SC is based on a combination of biochemical, radiological and histological signs and symptoms, including elevated levels of serum IgG4, intra- and extrahepatic biliary strictures detected by magnetic resonance cholangiography, and multifocal IgG4-lymphoplasmic infiltrations, sclerosing fibrosis of the bile ducts, seen at morphological assessment. Glucocorticoids (GCS) are the first line agents to achieve remission in patients with IgG4-SC. Most patients respond well to the systemic GCS. However, about 20% of patients (mostly those with extensive sclerotic intra- and/or extrahepatic abnormalities and signs of advanced disease / cirrhosis) show an insufficient or no response from the beginning of the treatment. The clinical case illustrates that timely verification of the IgG4-SC diagnosis may have an important prognostic value. The case history of a 62-year old female patient confirms the difficulties of the early diagnosis of the disease: for a relatively long time, the patient had the diagnosis of primary sclerosing cholangitis. Delay with GCS prescription (the treatment was initiated only at the stage of liver cirrhosis) had led to the lack of clinical efficacy and development of complications, such as relapsing cholangitis with advanced biliary strictures. In patients with suspected primary sclerosing cholangitis, timely differential diagnosis with IgG4-SC is relevant, because early GCS administration can slow the progression of the disease.