A Study on 5 Cases of Elevated Serum IgG4

Abstract

IgG4-related disease is a syndrome characterized by hyper-IgG4 gamma-globulinemia and infiltration of tissues by IgG4+plasma cells. Although glucocorticoid therapy can improve both the symptoms and serum IgG4 concentrations, differential diagnosis from other similar disorders is necessary. We report the cases of 5 patients who presented with swelling of the salivary glands and elevated serum IgG4 concentrations, and were suspected as having IgG4-related disease. Of the 5 patients, 2 were histopathologically diagnosed as having IgG4-related disease, the diagnosis remained unclear due to a lack of biopsy findings in 2 patients, and the remaining 1 patient was diagnosed as having malignant lymphoma after follow-up for 3 years. To obtain a definitive diagnosis, histopathological examination may have to be performed several times.