Budesonide with Low-Dose 6-Mercaptopurine as a Possible New Treatment for IgG4-Related Sclerosing Cholangitis and Systemic IgG4-Related Disease: A Case Report.

BACKGROUND Systemic IgG4-related disease is a rare disease that can affect the hepatobiliary system and may lead to tissue fibrosis and organ failure. Diagnostic criteria for IgG4-related disease are well established, and systemic glucocorticoids are recommended for initiation of treatment. Besides the beneficial properties of glucocorticoids, the long-term treatment with systemic steroids carries the risk of toxicity, especially in elderly patients, in whom IgG4-related disease is more common. Furthermore, disease relapses may occur during the tapering of steroids. Overall, the optimal treatment approach for maintenance therapy has not been clarified yet and is an area of current clinical research. CASE REPORT We present a patient with IgG4-related sclerosing cholangitis and histologically confirmed systemic (multi-organ) IgG4-related disease who was at increased risk of disease recurrence. The effects of immunosuppressants (prednisolone, 6-mercaptopurine, budesonide) on clinical symptoms, laboratory parameters (AST, ALT, AP, γGT, bilirubin), and imaging examinations (magnetic resonance cholangiography) were documented over 56 months. Control of IgG4-related sclerosing cholangitis was achieved - without systemic prednisolone - with the locally acting glucocorticoid budesonide in combination with low-dose 6-mercaptopurine. During treatment with 6-mercaptopurine, transient hepatotoxicity occurred, which was reversed by intermittent pausing and subsequent dose reduction. In addition, gangrenous cholecystitis occurred as a complication of immunosuppression and was treated by emergency cholecystectomy. CONCLUSIONS Budesonide could be a new treatment modality for IgG4-related sclerosing cholangitis. Systemic manifestations of immunoglobulin G4-related disease can be controlled with low-dose 6-mercaptopurine. Gangrenous cholecystitis may occur as a complication of immunosuppressive treatment.