Relevance of Recent Thymic Emigrants Following Allogeneic Hematopoietic Cell Transplantation for Pediatric Patients with Inborn Errors of Immunity

Serial measurement of RTE is a useful assessment of thymic function after HCT. In pediatric patients with IEI, older age at transplantation, greater intensity of conditioning, and occurrence of grade 2 to 4 acute GvHD were strongly associated with slower thymic-derived immune reconstitution. Mixed lymphoid donor chimerism was not associated with RTE in the linear mixed effects model. In addition to augmenting current anticipatory guidance on HCT outcomes, these findings may guide personalization of regimens to optimize clinical outcomes in IEI HCT.