Extra-pancreatic manifestations of IgG4-related systemic disease: a single-centre experience of treatment with combined immunosuppression

Background/Aim IgG4-related systemic disease (IgG4-RSD) is a systemic inflammatory disease distinguished by tissue infiltrates of IgG4+ plasma cells and elevated serum IgG4 levels. While IgG4-RSD often involves the pancreas, extra-pancreatic organs are also frequently affected. Here, we review the presentation and management of patients with extra-pancreatic IgG4-RSD. Methods A retrospective analysis was performed on patients diagnosed with extra-pancreatic IgG4-RSD identified from a single centre. Results Six patients with extra-pancreatic IgG4-RSD were identified. The median age of the patients was 64 years. The range of involved organs included lymph nodes (three patients), ocular adnexa, lung, kidneys, meninges and exocrine glands. The median delay in diagnosis was 13.5 months (460 months). Four patients had elevated serum IgG4 levels at diagnosis. Five symptomatic patients were commenced on combination immunosuppression, which included corticosteroids. Maintenance therapy with azathioprine was used in one patient, methotrexate and mycophenolate were each used in two patients, and cyclophosphamide in one patient. Four treated patients went into remission, while two patients had persistent radiological disease. One patient experienced two relapses. Conclusion IgG4-RSD can manifest in a variety of organs. Lack of awareness regarding this entity may delay diagnosis. Combination treatment of corticosteroids and conventional immunosuppression is effective.