Association of Torque Teno Virus With Corticosteroids, Rejection, and Infection in Adult and Pediatric Kidney Transplant Recipients

ABSTRACT Torque Teno Virus (TTV), an apathogenic anellovirus, is highly prevalent in solid organ transplant recipients. Evidence suggests that its replication varies with immunosuppression. This study investigated the association between TTV and rejection, infections, and corticosteroid‐free versus corticosteroid‐containing therapy, exploring individual trajectories and comparing TTV dynamics in adult and pediatric kidney transplant recipients. TTV was measured consecutively posttransplant in 310 adult and 20 pediatric kidney transplant recipients. All recipients were treated with tacrolimus and mycophenolate mofetil; 27% also received prednisolone. TTV was quantified using an in‐house qPCR. Increasing TTV load was associated with lower rejection risk (HR 0.90, 95% CI: 0.82; 0.99) but showed no association with infections. TTV levels were 0.66 (95% CI: 0.42; 0.90) log 10 copies/mL higher in recipients receiving prednisolone than those not receiving prednisolone ( p < 0.001). Levels peaked 3 months posttransplant, with no difference in levels and dynamics between adult and pediatric recipients. Stratification by pretransplant TTV levels revealed significant differences in levels over time. This study supports TTV levels as a predictor of rejection but not infection. Higher TTV levels in corticosteroid‐treated recipients suggest immunosuppressive adjustments should account for corticosteroid use. TTV levels maintained individual trend over time, indicating use of personalized monitoring, while similar kinetics in adult and pediatric recipients reinforce pediatric applicability.