The chimeric, monoclonal antibody basiliximab inhibits the proliferation and clonal expansion of activated T cells. To date basiliximab has been used only in combination with other immunosuppressive agents for rejection prophylaxis after solid organ transplantation. An infant underwent liver transplantion (LTx) at the age of 5 months because of biliary atresia. The primary immunosuppression consisted of cyclosporine and prednisolone. As a result of a steroid resistant rejection episode on day 26 post-LTx we had to switch the initial immunosuppressive regiment to tacrolimus and steroids. Because of severe cholestasis and assumed impaired enteral resorption we were forced to administer an unusually high dosage (2 mg/kg/day) of tacrolimus. Four months after LTx an intestinal B-cell lymphoma was diagnosed when the patient suffered from a small bowel perforation. After stopping the immunosuppressive medication we started treatment with the anti-CD20 monoclonal antibody rituximab for B-cell depletion. During the 12 wk no B cells were detectable in the peripheral blood by flow cytometry. In this setting we started a monotherapy with repetitive doses of basiliximab for immunosuppression. During the following course there was no further rejection and no recurrence of the tumor. From this experience we conclude that monotherapy with basiliximab after LTx and anti-CD20 treatment for B-cell lymphoma is efficient and safe.
