Response to varicella immunization in pediatric liver transplant recipients.

BACKGROUND: Individuals undergoing therapeutic immunosuppression are at risk of severe varicella-zoster virus (VZV) infection, particularly those without evidence of previous infection. METHODS: Eleven children, median age 10 months (range 5.5 months to 7 years and 9 months) received one dose of varicella vaccine (Varilrix, SmithKline Beecham plc, UK) before liver transplantation (median interval 95 days, range 40-289 days). The serological response to varicella vaccine was evaluated retrospectively and matched with the outcome and management of any subsequent exposures to VZV. RESULTS: Three children responded postimmunization, six children showed no response, and in two children the outcome was difficult to interpret having received blood products. Four children required varicella-zoster immunoglobulin prophylaxis posttransplantation, two of whom developed mild chickenpox. CONCLUSIONS: Only 3 of 11 children developed a clear antibody response to varicella vaccine. Administration of varicella vaccine did not affect the management of subsequent VZV exposures.

Tacrolimus (FK506) malabsorption: management with fluconazole coadministration.

We report the use of fluconazole to control primary immunosuppressive management with tacrolimus in a 9-year-old liver transplant recipient. Progressive increases in the doses of both cyclosporin (up to 20 mg/kg/day) and, subsequently, tacrolimus (up to 60 mg/day) failed to maintain immunosuppressive levels of both agents. After excluding poor compliance, drug interactions and analytical problems and identifying poor bioavailability (< 2.6%) and rapid clearance (4.2 l/h), fluconazole (100 mg/day) was initiated to inhibit tacrolimus metabolism and consistent therapeutic blood levels of tacrolimus were achieved. However, graft function had deteriorated irrevocably and retransplantation was performed. Simultaneous use of tacrolimus (5 mg/day) and fluconazole (100 mg/day) maintained immunosuppression after transplantation. Three weeks later, obstruction of the Roux loop caused deteriorating liver function and tacrolimus blood levels fell. After correction at laparotomy, stabilisation was achieved and discharge was possible on 5 mg tacrolimus b.i.d. plus fluconazole (100 mg).