A comparative study of T-cell depleted and non-depleted marrow transplantation for hematological malignancy

Sixteen patients with hematological malignancy received cyclophosphamide (120 mg/kg), fractionated total body irradiation (12 Gy), oral cyclosporin, and an HLA-identical sibling marrow transplant depleted of T cells by incubation with the monoclonal antibody anti-HuLy-m1 (CD2) and rabbit complement with (five patients) or without (11 patients) anti-HuLy-m8). These 16 patients were compared historically to 84 patients with hematological malignancy receiving cyclophosphamide (120 mg/kg), fractionated total body irradiation (12 or 14 Gy), oral cyclosporin, and unmanipulated HLA-identical sibling marrow, for parameters of engraftment and graft-versus-host disease (GVHD). Graft failure occurred in one of the 16 T-cell depleted recipients and in one of the 84 nondepleted recipients. Engraftment was slightly but significantly slower in the T-cell depleted group and bacterial infections significantly more frequent and severe than in the unmanipulated group. There was a suggestion that the severity of acute GVHD was reduced in those receiving T depleted marrow. Randomized trials will be necessary to determine if marrow T-cell depletion results in superior long-term leukemia-free survival.