Advances in the diagnosis and treatment of IgG4-related sclerosing cholangitis: a review

Abstract

Abstract Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is an IgG4-related disease characterized by bile duct fibroinflammatory wall-thickening and stenosis, resulting in obstruction jaundice, weight loss. Different regions of the bile duct can be involved, with the distal region being the most common. IgG4-SC can also have other organ involvement, such as the pancreas, urinary tract, salivary glands and lacrimal glands. In clinical practice, the manifestation of IgG4-SC is very similar to cholangiocarcinoma (CC) and primary sclerosing cholangitis (PSC), as well as pancreatic malignancies, while the treatment and prognosis are totally different. Japanese researchers ever established the clinical diagnostic criteria in 2012: (1) characteristic biliary imaging findings; (2) elevated serum IgG4 concentrations; (3) the coexistence of IgG4-related diseases except those of the biliary tract; and (4) characteristic histopathological features. According to our observations, IgG4-SC can be distinguished from CC with 100% specificity only at a cutoff of six times the upper normal limit. Imaging findings have low specificity for diagnosis, with the exception of intraductal ultrasonography, which can reflect the lesion with relatively high specificity. IgG4 plasma cell infiltration can be found in bile duct biopsy tissue, although this procedure is difficult. According to recent studies, the treatment of IgG4-SC relies mainly on corticosteroids. Following steroid treatment, most IgG4-SC patients can recover and their symptoms are resolved although a few patients relapse after steroid withdrawal. Maintenance of steroid therapy or alternative drugs is necessary in such cases. There is, however, no strong evidence for malignant transformation in IgG4-SC.