Lytic and latent EBV gene expression in transplant recipients with and without post-transplant lymphoproliferative...

Epstein-Barr virus (EBV) is associated with post-transplant lymphoproliferative disorder (PTLD), which has significant morbidity and mortality in transplant recipients. To devise prophylactic measures, we need predictors of PTLD and a better understanding of the physiopathogenesis of the disease.

To identify a molecular pattern of EBV gene products in blood that is specific to PTLD and can be used for the diagnosis of this disease.

We evaluated the ratio between latent and replicating EBV nucleic acids in individuals with PTLD by comparison with transplant recipients without PTLD and immunocompetent hosts with EBV DNA-emia. Subjects were prospectively identified between July 2009 and October 2010 at the University of Colorado Hospital. EBV DNA, LMP-2A Latency III and BZLF1 Lytic genes mRNA were quantified using real-time PCR.

We found that PTLD subjects (N = 7) had significantly higher EBV DNA-emia compared with non-transplant immunocompetent subjects (N = 69; p<0.0001), and transplant recipients without PTLD (N = 105; p<0.0001). The ratios between LMP-2A and BZLF1 mRNA in transplant recipients were significantly lower than in non-transplant subjects (p = 0.04). However, PTLD and non-PTLD transplant recipients displayed similar ratios.

These results suggest that EBV replication makes a larger contribution to the circulating EBV DNA in transplant recipients compared with immunocompetent hosts. Transplant recipients seem to lose control over EBV replication, which may contribute to the development of PTLD.