Allogeneic bone marrow transplantation from unrelated donors using in vivo anti-T-cell globulin

Antithymocyte globulin for graft-versus-host disease prophylaxis in transplants from unrelated donors: 2 randomized studies from Gruppo Italiano Trapianti Midollo Osseo (GITMO)

One hundred nine patients with hematologic malignancies, undergoing bone marrow transplants (BMT) from unrelated donors, were randomized in 2 consecutive trials to receive or not to receive antithymocyte globulin (ATG) in the conditioning regimen, as follows: (A) 54 patients (median age, 28 years; 39% with advanced disease) were randomized to no ATG (n = 25) versus 7.5 mg/kg rabbit ATG (Thymoglobulin; Sangstat, Lyon, France) (n = 29); (B) 55 patients (median age, 31 years, 71% with advanced disease) were randomized to no ATG (n = 28) versus 15 mg/kg rabbit ATG (n = 27). Grade III-IV graft-versus-host disease (GVHD) was diagnosed in 36% versus 41% (P =.8) in the first and in 50% versus 11% (P =.001) in the second trial. Transplant-related mortality (TRM), relapse, and actuarial 3-year survival rates were comparable in both trials. In fact, despite the reduction of GVHD in the second trial, a higher risk for lethal infections (30% vs 7%; P =.02) was seen in the arm given 15 mg/kg ATG. Extensive chronic GVHD developed overall more frequently in patients given no ATG (62% vs 39%; P =.04), as confirmed by multivariate analysis (P =.03). Time to 50 x 10(9)/L platelets was comparable in the first trial (21 vs 24 days; P =.3) and delayed in the ATG arm in the second trial (23 vs 38 days; P =.02). These trials suggest that (1) 15 mg/kg ATG before BMT significantly reduces the risk for grade III-IV acute GVHD, (2) this does not translate to a reduction in TRM because of the increased risk for infections, and (3) though survival is unchanged, extensive chronic GVHD is significantly reduced in patients receiving ATG.

Unrelated donor marrow transplantation in children with severe aplastic anaemia using cyclophosphamide, anti-thymocyte globulin and total body irradiation

We report a favourable outcome in 15 patients with severe aplastic anaemia (SAA) who were < 20 years of age and who underwent bone marrow transplantation (BMT) from a human leucocyte antigen (HLA)-matched unrelated donor. All patients were non-responders to intensive immunosuppressive therapy (IST) and were multiply transfused. The conditioning regimen consisted of cyclophosphamide (60 mg/kg/d, on d -4 and -3), anti-thymocyte globulin (2.5 mg/kg/d, on d -5 to -2) and total body irradiation (2.5 Gy x 2/d, on d -2 and -1). Patients received cyclosporine and methotrexate for prophylaxis of graft-versus-host disease (GVHD), except for the last four who received tacrolimus instead of cyclosporine. Donor/recipient pairs were identical for HLA class I and II antigens by serological typing, but four pairs were found to have a mismatch at the HLA-A, -B or -DRB1 locus by high-resolution typing. All patients achieved rapid engraftment and are alive at 2-86 months after transplantation (median follow-up, 51 months). Moderate to severe acute GVHD occurred in 5 out of 15 patients (33%); only one patient developed extensive chronic GVHD. Considering our encouraging results, unrelated donor transplantation for SAA is recommended as a salvage therapy in non-responders to IST.