EFFICACY OF QUANTITATIVE-ANALYSIS OF EPSTEIN-BARR VIRUS-INFECTED PERIPHERAL-BLOOD LYMPHOCYTES BY IN-SITU HYBRIDIZATION OF EBER1 AFTER LIVING-RELATED LIVER-TRANSPLANTATION - A CASE-REPORT

Background. We describe a 1-year-old female who underwent living-relat ed liver transplantation for biliary atresia and developed Epstein-Bar r virus (EBV)-related posttransplant lymphoproliferative disorder. Thi s disorder was resolved after withdrawal of immunosuppression therapy and administration of a high dose of acyclovir. Methods. To quantify t he extent of EBV activation and EBV load in peripheral blood, we measu red the levels of EBV-infected peripheral lymphocytes by in situ hybri dization (ISH) of EBV-encoded small mRNA 1 (EBER1). Results. The decli ne in the number of EBER1-positive lymphocytes (from 362/50,000 mononu clear cells to 0/50,000) after treatment was in accord with the patien t's clinical improvement. Conclusions. This finding showed that quanti tative analysis of EBV-infected peripheral lymphocytes by ISH of EBER1 is very useful for monitoring the EBV load and response to treatment of patients with EBV-related disorders. Furthermore, ISH may become al e important tool for the early diagnosis and prevention of life-threat ening posttransplant lymphoproliferative disorder in posttransplant pa tients.