Adoptive therapy with recipient-type CMV-specific T-cell clones in CMV-negative donor/CMV-positive recipient transplants. CMV-specific CD4⁺ T-cell clones were obtained from 2 CMV-positive patients before transplantation from CMV-negative donors. Clones were tested for alloreactivity against donor alloantigens. Those cross-reacting against donor were discarded, and the nonreactive were infused after transplantation. (A) Frequencies of CMV-specific T cells detected in these 2 patients at various time points after adoptive therapy infusion. (B) Donor-versus-recipient chimerism by DNA polymorphism in the 2 transplants. Lane i: donors' PBMCs; lane ii: recipients' pretransplantation PBMCs; lane iii: recipients' posttransplantation PBMCs; and lane iv: recipients' anti-CMV T-cell clones after adoptive therapy. Note, anti-CMV responses (lane iv) were of recipient origin (compare pattern with lane ii), unlike the bulk of the PBMCs (lane iii), which were of donor origin (compare pattern with lane i). (C) CMV antigenemias in 8 control CMV-positive patients who received transplants from CMV-negative donors showing prolonged CMV reactivation. (D) CMV antigenemias in the 2 CMV-positive patients who received transplants from CMV-negative donors who had received adoptive therapy. Note control of CMV reactivation. All data presented as mean ± SD.