Tumor infiltrating immune cells play an important role in host immune reactions against diffuse large B-cell lymphoma (DLBCL). In the present study, we have identified a subset of tumor infiltrating FOXP3-positive regulatory T cells (Tregs) in the initial DLBCL biopsy specimens and evaluated its prognostic significance. Ninety-six patients with DLBCL were retrospectively evaluated. Expression pattern of FOXP3 protein was examined using standard immunohistochemistry in paraffin-embedded tissue samples. The median overall survival (OS) was 28 months. Compared to the others, the patients with higher percentage of FOXP3-positive Tregs in the initial tumor biopsy, showed a significantly longer OS (p=0.003). When prognostic factors were evaluated in a multivariate model, the international prognostic index and the percentage of infiltrating FOXP3-positive Tregs in the initial biopsy were shown to be independent predictors of OS. In conclusion, the presence of increased percentage of FOXP3-positive Tregs in DLBCL predicts a better prognosis.
Disclosure:Research Funding: This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (0620220-1) and by the Korean Research Foundation Grant funded by the Korean Government (MOEHRD) (the Center for Healthcare Technology Development, Chonbuk National University, Jeonju 561-756, Republic of Korea).