Pathogen-specific immune reconstitution after alloanergized haploidentical bone marrow transplantation. (A) CD8⁺ T-cell reconstitution in patients with and without CMV reactivation. Mean values for absolute CD8⁺ cells/μL are shown. (B) Expansion of CMV-specific pentamer⁺ CD8 cells in vivo in UPN 24 in relation to a single episode of CMV antigenemia. (C) Absolute levels of CMV-specific pentamer⁺ CD8 cells in UPN 024 (gray dashed line indicates 10 cells/μL). (D) Primary CMV-specific response in a CMV-seropositive patient (UPN 021) who received alloanergized BMT from an HLA A2⁺ CMV-seronegative donor. CMV-specific pentamer⁺ CD8 cells were not detectable in the donor pretransplantation or in the donor bone marrow after alloanergization before infusion, but became detectable after a single episode of CMV antigenemia at D +37. A sustained expansion of CMV-specific pentamer⁺ CD8 cell was seen and no further episodes of CMV antigenemia occurred. Numbers in gated regions show HLA A2-restricted peptide (NLV) -pentamer⁺ cells, expressed as percentage of CD3⁺CD8⁺ T cells. BM, bone marrow; PB, peripheral blood; ND; not detectable above negative control frequency in pentamer-stained HLA A2⁻ donor cells. (E) Rapid and early expansion of EBV-specific pentamer⁺ CD8 cells in 4 patients who received alloanergized BMT from HLA A2⁺ EBV-seropositive donors.