J Med Virol. 2026 Aug;98(8):e71113. doi: 10.1002/jmv.71113.
ABSTRACT
Immune reconstitution (IR) after allogeneic hematopoietic stem cell transplantation (HSCT) is crucial to prevent transplant-related complications. Plasma viral load of Torque teno virus (TTV-VL), considered apathogenic and the main component of human virome, may reflect immunosuppression state. In this single-center prospective study we recruited 32 children undergoing HSCT to explore the potential role of TTV-VL as an IR marker and predictor of clinical outcome. Blood samples were obtained prior to stem cell infusion, on the day of transplantation, and on days +15, +30, +90, +180, +270, and +360 post-transplant. TTV-VL diminished after conditioning, increased after engraftment, and correlated with lymphopenia since day +30, consistent with previous reports. In exploratory analyses, correlations with clinical outcomes were limited by small sample size: higher TTV-VL at day +15 correlated with accumulated bacterial infection episodes and mortality at 1 year; at pre-HSCT and at +180 days TTV-VL predicted viral reactivations at the subsequent study timepoint; at +30, TTV-VL anticipated graft versus host disease. Associations with NK cell function and HLA/KIR variables were also observed, although no mechanistic inference could be drawn. Overall, these results are hypothesis-generating and warrant validation in larger studies.
PMID:42627020 | DOI:10.1002/jmv.71113
