Diagnostic features of IgG4-related disease

Objective To explore the clinical diagnostic features of IgG4-related disease (IgG4-RD). Methods The clinical data of 3 cases of IgG4-RD diseases confirmed by Pathology Department of Tai′an Central Hospital from January 2015 to June 2018 were analyzed retrospectively, and the pathomorphological features and immunophenotype of IgG4-RD were observed and their clinical diagnostic features were analyzed. Results Among the 3 patients, 2 cases were males and 1 case was female. Their age at the time of operation ranged from 76 to 80 years. All the patients with elevated plasma IgG4. Diffuse or flaky lymphocytes and IgG4+ plasma cell infiltration were observed under light microscope. Characteristic fibrosis was visible around the infiltrating cells. Typical fibrosis can be a spiral ring structure. It was accompanied by atrophy of normal tissues and organs such as the parotid gland and renal tubules. Conclusions IgG4-RD is a rare chronic autoimmune disease, which is characterized by a high serum IgG4 level and a large number of IgG4 positive plasma cell infiltration and significant fibrosis in the tissue. It is easily confused with tumor and other diseases in clinic, imaging and histology. Thorough understanding of the associated clinical features and immunohistochemic results is helpful in achieving the correct diagnosis. Key words: IgG4-related disease; Autoimmune disease; Immunohistochemistry