Microvascular density, CD68 and tryptase expression in human Diffuse Large B-Cell Lymphoma

• DLBCL is the most common form of Non-Hodgkin lymphoma.
• TAMs and mast cells are two major components of the tumor inflammatory infiltrate.
• CD68 and tryptase expression and MVD are increased in chemo-resistant DLBCL patients.

Diffuse Large B-cell Lymphoma (DLBCL) is the most common form of Non-Hodgkin lymphoma characterized by clinical and biological heterogeneity attributable both to the tumor cells and the complex tumor-microenvironment surrounding them. Tumor-associated macrophages (TAMs) and mast cells are two major components of the tumor inflammatory infiltrate with a definite role in enhancing tumor angiogenesis. In this study, we have investigated CD68 and tryptase expression and their relationship with microvascular density (MVD) in chemo-resistant and chemosensitive patients affected by DLBCL. CD68 and tryptase expression as well as MVD were increased in chemo-resistant patients when compared with chemosensitive patients. Tryptase expression showed a positive correlation with MVD, supporting a role for mast cell in DLBCL tumor angiogenesis, while CD68 correlation with MVD was not significant, indicating a different role for TAMs than angiogenesis in DLBCL.