18513 Background: Foxp3 is a key regulatory gene required for the development and function of: regulatory CD4+CD25high T cells (Treg) specialized in maintaining the balance between immunity and tolerance and activated conventional CD4+CD25low T cells without suppressive activity. Previous studies had reported the origin of Adult T-cell Leukemia/Lymphoma cells (ATLL) in Foxp3 T cells and in other lymphomas types the FOXP3 expression was only detected in the reactive T-cell background. Our objetive was to determine the presence of Treg phenotype cells by the FOXP3 expression in T-cell lymphomas. Methods: A retrospective study was performed on 48 samples collected from diverse T-cell lymphomas in our institution. A highly sensitive immunohistochemical method was used to demonstrate Treg phenotype by FOXP3 protein expression with a mouse monoclonal antibody (clone 236A/E7ABCAM) in most formalin-fixed paraffin-embedded tissue sections from lymph nodes, skin, bone marrow and extranodal sites samples as cavum and stomach. We did not co-stained with CD25 and considered a FOXP3+ tissue when positivity was > 20% of tumor cells. The statistical method was descriptive and survival was calculated using the Kaplan-Meier method. Results: Among the 48 evaluable T-cell lymphomas collected, 33 were ATLL, 8 unspecified peripheral T-cell lymphomas (U-PTCL), 6 mycosis fungoides (MF) and 1 cutaneous aggressive epidermotropic CD8(+) cytotoxic T-cell lymphoma. Among the 33 ATLL: lymphomatous=17, acute=11, smoldering=1, chronic=1, cutaneous=1 and undefined=2. FOXP3 expression in tumour cells was detected in 24% (8/33) of ATLL cases and in 37% (3/8) of U-PTCL. It was negative in MF tumour cells and aggressive epidermotropic CD8(+) cytotoxic T-cell lymphoma Among the ATLL cases FOXP3 positivity were obtained in 35% (6/17) of lymphomatous type; 18% (2/11) of acute ones and none in others ATLL types studied. Interestingly 3 U-PTCL had Treg phenotype and were related to EBV (LMP1 positive); two had extranodal primary ( parotide and cavum) and one was nodal. We failed to demonstrate any correlation between FOXP3 status and survival. Conclusions: Some ATLL and U-PTCL had Treg phenotype. In our work Foxp3 expression was not found to be a prognostic factor. No significant financial relationships to disclose.
Dendritic cells loaded with apoptotic tumour cells induce a stronger T-cell response than dendritic cell–tumour hybrids in B-CLL