Effect of CMV and donor-derived CMV⁺CD8⁺ T-cell recovery in the allogeneic HCT recipient. (A) Risk factors, clinical manifestations, and transplant outcomes associated with CMV infection in the allogeneic HCT recipient. (B) PS and NPS of donor CMV (pp65 antigen peptide)-specific CD8⁺ T cells associate with low or high viral DNA levels (international units per milliliter) of clinically significant CMV DNAemia (reactivation), respectively. In addition, 3 separate HCT recipient subgroups were delineated based upon distinct donor CMV⁺CD8⁺ profiles: EC who experienced no CMV DNAemia following allogeneic HCT had the highest levels of PS; NC who experienced high levels of CMV DNAemia (>1000 IU/mL) and required preemptive antiviral therapy had the lowest levels of PS and highest levels of NPS; and SC who self-resolved episodes of low levels of CMV DNAemia (<200 IU/mL) without antiviral therapy had predominantly higher levels of PS than NPS. α, anti-; ATG, antithymocyte globulin; D, posttransplant day; D/R, donor/recipient; BM, bone marrow; HLA, human leukocyte antigen. +, promotes; -, inhibits.