Is there a relationship between the clinicopathological features of classic Hodgkin lymphoma subtypes and an increase in IgG4-positive plasma cells?

An IgG4 ( +) plasma cell increase can be observed in classic Hodgkin lymphoma (CHL) in addition to IgG4-related disease. IgG4 ( +) plasma cells can affect therapy or prognosis in CHL because the microenvironment of CHL can help cancer escape immune surveillance. Therefore, we aimed to determine the relationship between IgG4 ( +) plasma cell increase and the clinicopathological parameters of CHL subtypes. A total of 76 cases diagnosed with CHL by lymph node excision between 2006 and 2020 in our hospital were selected. The probable histological features of IgG4-related disease were utilized for diagnosis. The presence of IgG4 was determined by immunohistochemistry. IgG4 ( +) plasma cell increase was mostly seen in nodular sclerosis CHL, but it was also observed in other CHL subtypes, except for lymphocyte-rich CHL. While IgG4 ( +) plasma cell increase was related to a limited stage of progression, it was not related to mean age, gender, pediatric or adult status, involvement of the mediastinum in the cancer, the presence or absence of the Epstein–Barr virus, overall survival, and neutrophil or eosinophil infiltration. It was also inversely correlated with extranodal involvement, granuloma, and necrosis. IgG4 ( +) plasma cell increase can affect stage, subtype, and microenvironment in CHL and has more influence on disease via changes in rising cases; thus, these findings can serve as a guide for large studies, which can help improve treatment and prognosis in CHL.