Peripheral T-cell lymphomas of the angioimmunoblastic lymphadenopathy (AILD) type roughly correspond to lymphogranulomatosis X (LgX). They are currently treated with prednisone, either as a single treatment or with combination chemotherapy. However, both approaches are associated with high risks in this usually elderly patient population (median age 64 years). While looking for therapeutic alternatives to avoid these problems, the efficacy of low dose recombinant interferon-alpha 2a was examined. Patients received 3 x 10(6) IU daily as a subcutaneous (s.c.) injection. Those who achieved a complete remission continued with a maintenance treatment of 3 x 10(6) IU s.c. three times per week. A total of 14 patients received interferon. Twelve were evaluable for response. Six received interferon as primary and six as secondary treatment after the failure of previous treatment with prednisone or chemotherapy. Complete remissions were achieved in four, partial remissions in another four of 12 patients, whereas in the remaining four patients no change or progressive disease was observed. The median remission duration was 3.5 months; the longest durations of complete remissions were 6+ and 7 months. It is concluded that low dose interferon-alpha is an effective and well tolerated drug in T-cell lymphomas of the AILD (LgX) type. It is useful for salvage treatment in patients with contraindications or refractory to combination chemotherapy. It may be useful in adjuvant or maintenance treatment.