Epstein-Barr virus-specific T-cells in pediatric liver transplant recipients

To determine Epstein-Barr virus (EBV)-specific T-cell responses after pediatric liver transplantation (LT), we monitored EBV viral load and IFNγ-producing specific T-cells reacting to BZLF1, EBNA1, and LMP2 antigens from peripheral immune cells before LT until 48 weeks after LT. Among forty children, seven (17.5%) developed EBV infection. Two were subsequently diagnosed with post-transplant lymphoproliferative disorders. The infected children exhibited fewer EBNA1-specific CD4 + T-cells and CD8 + T-cells before LT (P = 0.01 and P = 0.02, respectively) than non-infected children. At 32 weeks after LT, EBNA1-specific CD4 + T-cells, LMP2-specific CD4 + T-cells, and BZLF1-specific CD8 + T-cells were lower in the infected children (P = 0.02, P < 0.01, and P = 0.02, respectively). EBV infection-free survival rates (IFSR) were higher in groups with detected EBNA1-specific CD4 + or CD8 + T-cells prior to LT compared to non-detected group. No patients with detected EBNA1-specific CD8 + T-cells reported EBV infection after LT (a 48-week IFSR of 100%). However, the differences of IFSR were statistically insignificant (HR 0.25; 95% CI 0.05 to 1.3, and HR 0.42; 95% CI 0.09 to 1.86, respectively). LMP2-specific CD4 + T-cells were negatively correlated with EBV viral load (r = - 0.702, P = 0.02). In conclusion, EBV infection after pediatric LT is associated with lower expression of EBV-specific T-cells, which may be potential predictors for the infection after LT.