Daratumumab increases the proportion of effector T helper cells and Th17 cells. (A) Naive, effector, central memory, and effector memory Th cell levels measured the PBMCs of healthy donors (n = 6) or patients with CLL (n = 13). These cells were categorized as such based on the following immunophenotypic markers: CD3⁺CD8^-CD4⁺CCR7⁺CD45RO⁻ (naive), CD3⁺CD8⁻CD4⁺CCR7⁻CD45RO⁻ (effector), CD3⁺CD8⁻CD4⁺CCR7⁺CD45RO⁺ (CM; central memory)⁻ CD3⁺CD8⁻CD4⁺CCR7⁻CD45RO⁺ (EM; effector memory), CD3⁺CD8⁻CD4⁺CCR6⁻CXCR3⁺ (Th1), CD3⁺CD8⁻CD4⁺CCR6⁻CXCR3⁻ (Th2), CD3⁺CD8⁻CD4⁺CCR6⁺CXCR3⁻ (Th17). (B) The effect of daratumumab (D, 1 µg/mL, 72 hours) in modulating proportion (%) of effector Th cells from patients with CLL (n = 10) was examined. (C) Different T helper cell subset (Th1; Th2 and Th17) were measured in the same healthy donors or patients with CLL, as in panel C. (D) The effect of daratumumab on altering the percentage of Th1, Th2, and Th17 cells from patients with CLL (n = 8) was tested as described in panel B. Contour plots are representative, and compiled data are presented as mean ± SEM with individual data points overlaid. Each experiment was performed at least twice in duplicate. *P < .05.