[Autograft of bone marrow treated by immunotoxin T 101 for the treatment of T-cell leukemia and lymphoma. Initial clinical cases].

In order to consolidate a complete or partial remission, 4 patients with T-cell malignancy received cyclophosphamide 120 mg/kg plus total body irradiation, followed by reinfusion of cryopreserved autologous bone marrow purged in vitro by the immunotoxin T 101 (SR 41322) composed of the murine monoclonal T 101 antibody coupled with the A chain of ricin. The immunotoxin was applied in doses of 10(-9) and 10(-8) M for periods of 4 and 20 hours at 37 degrees C. The recovery of CFUc and BFUe progenitors was total following incubation with IT 101, but reduced after cryopreservation (1-15 to 80% for CFUc,-33 to 47% for BFUe), haematopoietic recovery occurred within normal delays, demonstrating that autologous bone marrow pretreated with the immunotoxin can be successfully transplanted. However, the slow increase in lymphocytes and the occurrence of lethal infection in 2 cases indicate that an in-depth study of immunological reconstitution after in vitro treatment of bone marrow with ITT 101 is necessary.