Evaluation of the Status of Intraparenchymal Plasma Cells in Terms of IgG4 Expression in Patients Diagnosed With Idiopathic Granulomatous Mastitis

Abstract

Background and Objectives Idiopathic granulomatous mastitis (IGM) is a chronic inflammatory lesion that mimics the clinical symptoms of carcinoma. Another type of chronic granulomatous mastitis is immunological mastitis, which is related to the infiltration of IgG4 plasma cells. This study aims to determine the status of IgG4 positive plasma cells in IGM samples. Subjects and Methods This is an analytical-cross-sectional study. 46 women diagnosed with IGM were selected for the study using census method. The percentage of IgG and IgG4 in plasma cells was determined based on immunohistochemical method. Age and type of surgery were also recorded. The data was entered into SPSS software, version 22 and analyzed using statistical tests. P<0.05 were considered statistically significant. Results The mean age of patients was 35.02±6.82 years. The mean percentage of IgG positive plasma cells among tissue inflammatory cells was 6923±23.42 and the mean percentage of IgG4 positive plasma cells was 23.39±22.33. Among infiltrated plasma cells, 1.89% were positive for IgG4 and the ratio of IgG4 to IgG in plasma cells was 0.91. Based on the results of Pearson correlation test, a positive and significant correlation was found between the percentage of IgG4 and IgG in plasma cells (r=0.600, P=0.004). Conclusion A significant percentage of infiltrated plasma cells are IgG4 positive, which can play a role in the development of IGM. Therefore, further investigation and comparison with immunological mastitis is recommended.