Remission of posttransplant lymphoproliferative disorder after interferon alfa therapy

Posttransplant lymphoproliferative disorder (PTLD) is one of the major complications of immunosuppressive therapy. PTLD is strongly associated with the Epstein-Barr virus (EBV). It is believed that EBV-infected B cells proliferate in an unchecked manner due to suppression of cytotoxic T cells and elevation of B cell-promoting cytokines. There is no consensus on the treatment of PTLD other than reduction of immunosuppressive therapy. We report a case of PTLD with monoclonal B cells confined to the lymph nodes. The patient did not initially respond to reduction of immunosuppression, oral acyclovir, and intravenous immunoglobulin injection. She subsequently responded when subcutaneous injections of interferon alfa (5 million U) were given three times a week. The patient received a 3-mo course of interferon and remained in remission 12 mo after treatment. Her graft function was well maintained, and cyclosporin A was restarted 2 mo after achieving remission. The clinical manifestations, risk factors, pathogenesis, and treatment of PTLD, as well as 12 previously reported cases of PTLD treated with interferon, were reviewed. On the basis of the results presented here, it appears that interferon alfa may be useful in treating PTLD and that there is a need for further clinical trials.