Decreasing the Epstein-Barr virus load by adjusting the FK506 blood level.

To prevent post-transplant lymphoproliferative disease (PTLD), the viral load must be diminished before the symptoms of Epstein-Barr virus (EBV) infection appear. Twenty-three consecutive liver transplant recipients were entered into our study to identify the characteristics of post-transplant EBV-infected patients and to clarify the correlation between the FK506 blood level and EBV load. After transplantation, EBV-DNA appeared more frequently in patients who had been seronegative before transplantation than in seropositive patients (10/13 versus 1/10; P=0.0014). As for rejection, resistance to steroid pulse therapy, and FK506 trough level, there were no significant differences between patients with and without EBV infection. In patients with primary EBV infection after transplantation, there was a strong correlation ( r=0.681) between the FK506 level and the viral load. In liver transplant recipients, especially in those seronegative for EBV, it is necessary to check the viral load by polymerase chain reaction (PCR) carefully after liver transplantation, before any symptom appears.