Assessment of cellular glucose uptake within intratumoral lymphocyte subsets and determinants of SUV_lesional. (A) Representative 2-NBDG uptake of intratumoral CD19⁺, CD8⁺, and CD4⁺ cells, by flow cytometry. 2-NBDG, a fluorescently tagged FDG analogue, was used to determine cellular glucose uptake. Darker shades represent negative controls. There was a strong correlation between intratumoral CD19⁺ cells and light-chain–restricted monoclonal CD19⁺ FL tumor cells (Spearman r = 0.97; P < .0001), and hence intratumoral CD19⁺ cells were representative of FL B cells. (B) Combined results from 20 FL TIL samples of 2-NBDG uptake within intratumoral CD19⁺, CD8⁺, and CD4⁺ cells. (C) Percentage lymphocyte contribution to overall glucose uptake after normalizing for the fraction of CD19⁺, CD8⁺, and CD4⁺ live cells within each of the FL TILs. Average live cell infiltration: CD19⁺ cells, ∼64%; CD8⁺ cells, ∼4%; and CD4⁺ cells, ∼18%. (D) Twelve patients with prebiopsy FDG-PET scans had SUV_max obtained from their subsequently excised lymph node (SUV_lesional). SUV_lesional values were categorized into a low and high state using a mean cutoff threshold (mean SUV_lesional, 6.5). Lymphocyte (CD19, CD8A, and CD4) and macrophage (CD68) gene infiltration was assessed within subsequently excised lymph node tissue samples by multiplex gene hybridization. Gene counts are reported according to the prebiopsy SUV_lesional state. The Wilcoxon rank-sum test was used for all analyses.