RESUMEN
BACKGROUND: Accurate functional assessment of patient immunosuppression after solid-organ transplantation remains elusive. Despite therapeutic serum immunosuppressive drug levels many lung transplant recipients still develop allograft rejection. We investigated the hypothesis that detection of latent Epstein-Barr virus (EBV) in peripheral blood may be a functional marker for the net effects of administered immunosuppression. METHODS: A retrospective analysis was performed on data obtained from a prospective trial investigating the ability of a novel EBV polymerase chain reaction (PCR) panel for LMP (latent membrane protein 1), EBNA (EBV nuclear antigen) and EBER (EBV-encoded RNA) to predict future development of post-transplant lymphoproliferative disorder (PTLD). Thirty-one lung transplant patients were followed for up to 2 years after transplantation with EBV PCR panels performed on plasma and whole blood. Patients were assessed for occurrences of Grade 2 or higher acute rejection and episodes of infection. RESULTS: Patients with whole blood EBER-positive PCR had a statistically significant lower incidence (45% vs 83%) of Grade 2 or higher acute allograft rejection than patients with no positive assays (odds ratio [OR] = 0.17, 95% confidence interval [CI] 0.021 to 1.2, p = 0.048). Positive whole blood EBER PCR did not correlate with increased risk for infectious complications (OR = 1.6, 95% CI 0.22 to 11, p = 0.69). CONCLUSIONS: These results suggest that whole blood EBER EBV PCR load may represent an important functional measure of immunosuppression in solid-organ transplant patients.