Supplementary Materials and Methods from T Cells in Tumors and Blood Predict Outcome in Follicular Lymphoma Treated with Rituximab
ARTICLE ABSTRACTPurpose: T cells influence outcome in follicular lymphoma, but their contributions seem to be modified by therapy. Their impact in patients receiving rituximab without chemotherapy is unknown.Experimental Design: Using flow cytometry, we evaluated the T cells in tumors and/or blood in a total of 250 follicular lymphoma patients included in two Nordic Lymphoma Group randomized trials that compared single rituximab with IFN-α2a–rituximab combinations.Results: In univariate analysis, higher levels of CD3+, CD4+, and CD8+ T cells in both tumors and blood correlated with superior treatment responses, and in multivariate analysis, tumor-CD3+ (P = 0.011) and blood-CD4+ (P = 0.029) cells were independent. CD4+ cells were favorable regardless of treatment arm, but CD8+ cells were favorable only in patients treated with single rituximab, because IFN-α2a improved responses especially in patients with low CD8+ cell levels. Higher levels of blood-CD3+ (P = 0.003) and blood-CD4+ (P = 0.046) cells predicted longer overall survival, and higher levels of blood-CD8+ cells longer times to next treatment (P = 0.046).Conclusions: We conclude that therapeutic effects of rituximab are augmented by tumor-associated T cells for rapid responses and by systemic T cells for sustained responses. CD4+ and CD8+ cells are both favorable in patients treated with rituximab. IFN-α2a abrogates the negative impact of few CD8+ cells. Clin Cancer Res; 17(12); 4136–44. ©2011 AACR.