Low Level of Blood CD4⁺ T Cells Is an Independent Predictor of Inferior Progression-free Survival in Diffuse Large B-cell Lymphoma

Immune cell subsets in the blood of patients with diffuse large B-cell lymphoma before therapy were characterized by flow cytometry, and the levels of various T-cell types and natural killer cells were correlated with the eventual outcomes. High absolute levels of CD4 cells in the blood correlated with better progression-free survival and, to a lesser extent, overall survival, independent of patient age and International Prognostic Index score. Background Tumor-infiltrating immune cells influence diffuse large B-cell lymphoma (DLBCL) outcomes. Relatively little, however, is known about the significance of peripheral blood immune cell numbers on DLBCL behavior. Patients and Methods In the present study, 43 patients with newly diagnosed DLBCL had pretreatment multiparameter peripheral blood flow cytometry performed to assess the immune cell numbers. These cell numbers were correlated with the outcomes of progression-free survival (PFS) and overall survival. Results After follow-up period of 0.8 to 152 months (median, 73), 25 patients (56%) were still alive. As continuous variables on univariate analysis, the predictors of PFS were patient age and absolute CD4 cell count (ACD4C), with the International Prognostic Index (IPI) marginally significant. Age was also a significant predictor of overall survival, and the IPI and ACD4C were marginally significant (P = .08). The 17 patients with a greater ACD4C (≥ 450/mm³) had better 5-year PFS than the 26 with a low ACD4C (88% vs. 50%; P = .02). Multivariable analysis, including age as a continuous variable, IPI group, and ACD4C of 450/mm³ showed that age and ACD4C were significant for PFS (P = .01 and P = .02, respectively). Conclusion Our data, although from a small series, suggest that the blood ACD4C might be a predictor of PFS for patients with DLBCL, independent of age and the IPI.