The prognostic role of tumor-associated macrophages and dendritic cells in classic Hodgkin's lymphoma.

Tumor-associated macrophages (TAMs) and dendritic cells (DCs) may play a role in tumor progression as a part of the tumor microenvironment in many neoplasms, including those in Hodgkin's lymphoma. The current study investigated the relationship between the presence and density of macrophages and dendritic cells in the background of classic Hodgkin's lymphoma (CHL) and different clinicopathological parameters, including survival and response to therapy. CD68 and CD1a immunohistochemical staining were used to detect and highlight macrophages and dendritic cells, respectively, in 61 cases of CHL. CD68 was expressed in all studied cases, with no significant association with the studied parameters. In total, 54.1% (33/61) of cases showed CD1a expression. High CD1a expression (>7%) was associated with localized lymphadenopathy (p=0.01), early stage (p=0.005), and good revised international prognostic index (R-IPI) (p=0.07). Hodgkin's lymphoma cases that showed high CD68 and low CD1a were associated with adverse prognostic parameters such as advanced stage (p=0.03) and generalized lymphadenopathy (p=0.05). Old age (>60 years) (P=0.005), poor R-IPI (P=0.010), and negative CD1a expression (P=0.045) were significantly associated with poor outcome. Finally, our study demonstrated the importance of the presence and density of DCs in determining progression and prognosis in CHL. A certain interaction between TAMs and DCs may affect the progression of CHL. Further investigation is required to clarify whether TAMs release certain factors that decrease the number or function of DCs.