Kinetics of CMV-specific T cells with TCR nucleotide sequences also present in the infused T-cell products in patients with and without viral loads after infusion. Positive CMV viral loads were detected in 5 out of 13 patients that received a T-cell product containing CMV-specific T cells. PB samples that were obtained before and after infusion of the products were sorted by MACS for CD8⁺ T cells followed by mRNA isolation and sequencing of the TCRs. The numbers of target antigen–specific CD8⁺ T cells per liter blood were calculated by multiplying the frequencies of CMV-specific TCR nucleotide sequences with the absolute numbers of CD3⁺/CD8⁺ T cells per liter. CMV viral loads (dashed lines with gray area under the curve) and absolute numbers of CMV target antigen–specific T cells in PB samples are illustrated from the moment just before product infusion (day 0) until the end of follow-up. Shown are the kinetics of CMV target antigen–specific T cells in patients with CM -reactivations in whom TCR nucleotide sequences were found that only appeared after infusion of the products (A) and appeared before and after infusion of the products (B). Shown are the kinetics of CMV target antigen–specific T cells in patients without detectable CMV viral loads in whom TCR nucleotide sequences that were identical to the products were found that only appeared after infusion of the products (C) and appeared before and after infusion of the products (D). NP, not performed.