Epstein-Barr Virus Gene Expression, Human Leukocyte Antigen Alleles and Chronic High Viral Loads in Pediatric Renal Transplant Patients

Background. Studies have identified solid organ transplant recipients who remain asymptomatic despite maintaining chronic high Epstein-Barr virus (EBV) viral loads. We examined clinical manifestations, EBV gene expression, human leukocyte antigen (HLA) alleles, and specific T-cell responses to EBV infection in pediatric renal transplant patients. Methods. Seventeen pediatric renal transplant patients were categorized according to EBV viral load into those with chronic high viral loads (CHL) and recipients who resolve EBV infection (REI). EBV gene expression was analyzed using real-time PCR assays and EBV-specific T cells were analyzed by flow cytometry. Results. EBV gene, EBV-encoded small RNA 1, was expressed at significantly higher levels in CHL compared with EBV seropositive controls (P=0.005) and raised compared with REI. BamHI A right-ward transcripts were also expressed at higher levels in CHL patients (P=0.03) than in REI. Expression of latent genes, EBNA1, LMP1, LMP2, and lytic gene BZLF1 were restricted to the CHL group with viral gene expression varying over time. HLA-A(star)02 allele expression was predominant in CHL patients (80%) and GLC lytic-specific cytotoxic T-lymphocytes were absent. In contrast, HLA-B(star)08 allele expression was prevalent in REI patients (71%) and RAK lytic cytotoxic T-lymphocytes were detected in all patients. Conclusion. EBV gene expression in CHL carriers differs from those that resolve infection and should be interpreted alongside HLA polymorphisms.