EV effects on PBMC survival. PBMCs were cultured for 7 days with or without addition of day 0 EVs. Cell counts were performed at days 0 and 7, and at harvest cells were stained for CD3, CD4, CD8, CD19, CD14, and CD56 expression. Five PBMC preparations and 5 independent EV isolates were used for this experiment (**P < .01). (A) Absolute counts of PBMCs at day 7 relative to baseline count of 1 × 10⁶/mL. (B) Percentage of cells expressing markers of T cells, B cells, monocytes, and natural killer cells at day 7.