Valganciclovir suppressed Epstein Barr virus reactivation during immunosuppression with alemtuzumab

BackgroundReactivation of latent herpes viruses occurs with immunosuppression. Alemtuzumab is an antibody targeting CD52, which is expressed on all B- and T-cells. Treatment with alemtuzumab leads to profound T-cell suppression, and reactivation of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) occurs. Valganciclovir is used as an anti-CMV prophylaxis during alemtuzumab therapy.ObjectiveTo determine if EBV reactivation is decreased with valganciclovir prophylaxis.Study designPlasma EBV DNA was serially quantified by quantitative polymerase chain reaction with a World Health Organization EBV standard in patients receiving alemtuzumab therapy with valganciclovir as anti-CMV prophylaxis.ResultsTwenty-nine patients were studied. A total of 258 samples were quantified, at a median of 7 (3–25) specimens per patient. Twenty-four patients never had any quantifiable EBV DNA. Five patients (17%) developed EBV reactivation. Two patients had EBV reactivation at very low levels of about 10³ IU/mL, 3–4 logs lower than those typically found in post-transplant lymphoproliferative diseases. Three patients had EBV reactivation at higher levels of 10⁴ IU/mL, which only occurred after two courses of alemtuzumab were administered. EBV reactivation subsided spontaneously in four cases. One patient developed EBV-positive Hodgkin lymphoma, but he had also received previously another potent T-cell suppressing drug fludarabine.ConclusionValganciclovir suppressed EBV reactivation during alemtuzumab therapy. It might be a useful prophylaxis in immunocompromized patient populations at high risk of EBV reactivation.