Asymptomatic Epstein-Barr Virus Shedding in the Urine of Kidney Transplant Recipients: Case Reports and Review of the Literature

Epstein-Barr virus (EBV) is associated with a wide range of malignancies and complications like post-transplant lymphoproliferative disorder (PTLD). To suppress active EBV infection in transplant recipients, who are at a heightened risk of developing PTLD, EBV DNAemia monitoring has been recommended. Quantitative multiplex real time polymerase chain reaction (QMRTPCR) offered the advantage of detection of more than one target in the same sample. We present four cases of kidney transplant recipient who were admitted for rising serum creatinine between 9 and 20 months post-transplant with a suspicion of BKV-associated nephropathy. All but one patient had unusual sonography findings in their genitourinary tracts and were positive for urinary culture for bacteria. Using a commercial QMRTPCR that could detect and quantitate BKV, EBV and cytomegalovirus simultaneously, all patients were positive for EBV in their urine for the levels between 2500 and 8×108 U/mL. None of the patients had any symptoms regarding this finding. On following up survey 3 month post discharge from hospital, all patients were negative for plasma and urine EBV. Absent of EBV DNAemia together with alternating phases of detectable EBV in urine might reflect the presence of functionally efficient central/effector memory T cells against EBV. The significance of this finding in immunocompromized patients necessitates prospective longitudinal studies.