Interferon-alpha treatment of posttransplant lymphoproliferative disorder in recipients of solid organ transplants.

Posttransplant lymphoproliferative disorder (PTLD) has been treated with decreased immunosuppression, antiviral medications, anti-B lymphocyte agents, radiation therapy, and/or chemotherapy. However, a standardized stepwise approach to treatment has not been previously evaluated. In the present study, 19 consecutive patients presenting to a single institution with newly diagnosed PTLD were treated according to a sequential protocol that consisted of (1) a reduction in immunosuppressive medications plus, if feasible, resection or definitive radiation therapy of localized disease, (2) interferon-alpha, and (3) systemic chemotherapy. Of the 3 patients presenting exclusively with localized disease, two were treated with resection of pulmonary parenchymal nodules and one was treated with radiation therapy to a paraspinous mass, without evidence of recurrence at a mean follow-up of 31 months (range, 8 to 46 months). Sixteen patients presented with PTLD not amenable to local therapy, and they were treated daily with 3x10(6) units/m2 subcutaneous interferon-alpha. Total regression of PTLD (defined as disappearance of the tumor mass by physical examination or computed tomography scanning) was found in 8 of 14 patients who received at least 3 weeks of interferon therapy. Interferon-alpha therapy was continued for 6 to 9 months in the eight patients judged to be responders. None of these patients have relapsed to date with the same neoplastic clone. Two patients, however, developed new neoplastic clones. Seven patients received systemic chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) (n=1), EPOCH (etoposide, vincristine, and doxorubicin administered as a continuous infusion, with an intravenous bolus of cyclophosphamide and oral prednisone) (n=4), or EPOCH followed by DHAP (dexamethasone, cytarabine, and cisplatin) (n=2) after failure of interferon-alpha; five patients had a complete response. Only 1 of the 19 patients died of uncontrolled PTLD. These results suggest that the majority of solid organ transplant recipients who develop PTLD can be safely and successfully treated using a sequential approach to therapy.