IgG4 Related Syndrome: Another Multiorgan Disease in the Interest Field of Internal Medicine

Background: IgG4-related disease is a rare, clinical and pathologic disease entity of unknown etiology. Its main features are increased serum concentrations of IgG4 > 1,35 g/l, lymphocyte and IgG4+plasma-cell infiltration within tissues, fibrosis or sclerosis. The classical presentation of IgG4-RSD is pancreatitis which is combined with the involvement of biliary ducts in 74 percent of patients. Extrapancreatic manifestations include: abdominal or mediastinal lymphadenopathy; the involvement of salivary glands and lacrimal glands, kidneys, lung, retroperitoneum. Since IgG4-related disease is a multiorgan lymphoproliferative syndrome, it requires a careful differential diagnosis from other distinct disorders (sarcoidosis, immune rheumatic diseases, hematologic diseases, malignancies). Another distinctive feature is a fairly fast response to steroids, that represents the first-choice therapy. Immunosuppressant drugs (azathioprine, mycophenolate mofetil, methotrexate) might be chosen as glucocorticoid-sparing medications or to maintain steroid-induced remission (Fig. 1). Methods: We report the case of a 70-year-old man and we performed a brief review of loiterature. Results: Our patient has a clinical history including bronchial asthma, aortic aneurysm, histologically confirmed retroperitoneal fibrosis causing hydroureteronephrosis, prostatitis, interstitial pulmonary fibrosis, sclerosing chronic pancreatitis (histologically documented), previous chronic cholecystitis (histologically confirmed), previous pericarditis, xeroftalmia, polyclonal hypergammaglobulinemia, eosinophilia. His serum IgG4 levels were significantly increased (5560 mg/dl). In regard to the above mentioned elements a systemic disease characterized by elevated serum levels of IgG4 and IgG4-positive lymphoplasmacytic infiltrative lesions in several tissues, was suspected. Immune-rheumatic diseases and infectious diseases were excluded. Steroid treatment was started achieving a significant swift response. Conclusion: Until now IgG4 related disease has been considered rare in the West and exclusive of Japanese and Korean countries, our case report leads us to reflect on the necessity to take into account this disease in patients with multisystemic involvement.