Distribution patterns of dendritic cells and T cells in diffuse large B-cell lymphomas correlate with prognoses

Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphomas, accounts for 30% to 40% of all lymphoma cases. However, long-term survival by current chemotherapy was achieved in only 40% of patients, warranting the development of novel therapeutic strategies including T-cell immunotherapy. However, the level of baseline immune activation in DLBCL is unclear.

The density and distribution of dendritic cells and T cells in 48 cases of primary DLBCL was evaluated by immunohistochemistry.

Increased numbers of intratumoral CD1a+ dendritic cells and increased S100+ cells and CD45RO+ T cells around the edges of the tumors were seen in 10 of 48 (21%), 9 of 48 (19%), and 10 of 48 (21%) cases and these were correlated with a favorable prognosis (P = 0.015; P = 0.070, and P = 0.017, respectively), along with increased granzyme B+ T cells in tumor beds (P = 0.013). Increased peritumoral T cells were correlated with tumor expression of HLA-DR (r = 0.446; P = 0.002). Extranodal lymphomas showed fewer tumor-associated CD45RO+ T cells (r = -0.407; P = 0.001) and less conspicuous dendritic cell infiltrates.

In DLBCL, the presence of baseline antitumor immune response is associated with favorable clinical outcome, and thus adjuvant T-cell immunotherapy may further boost treatment responses.