Improved outcome with T-cell-depleted bone marrow transplantation for acute leukemia.
OBJECTIVE
To eliminate the risk of rejection and lower the risk of relapse after T-cell-depleted bone marrow transplants in acute leukemia patients, we enhanced pretransplant immunosuppression and myeloablation.


METHODS
Antithymocyte globulin and thiotepa were added to standard total-body irradiation/cyclophosphamide conditioning. Donor bone marrows were depleted ex vivo of T lymphocytes by soybean agglutination and E-rosetting. This approach was tested in 54 consecutive patients with acute leukemia who received transplants from HLA-identical sibling donors or, in two cases, from family donors mismatched at D-DR. No posttransplant immunosuppressive treatment was given as graft-versus-host disease (GVHD) prophylaxis.


RESULTS
Neither graft rejection nor GVHD occurred. Transplant-related deaths occurred in six (16.6%) of 36 patients in remission and in seven (38.8%) of 18 patients in relapse at the time of transplantation. The probability of relapse was .12 (95% confidence interval [CI], 0 to .19) for patients with acute myeloid leukemia and .28 (95% CI, .05 to .51) for patients with acute lymphoblastic leukemia who received transplants at the first or second remission. At a median follow-up of 6.9 years (minimum follow-up, 4.9 years), event-free survival for patients who received transplants while in remission was .74 (95% CI, .54 to .93) for acute myeloid leukemia patients and .59 (95% CI, .35 to .82) for acute lymphoblastic leukemia patients. All surviving patients have 100% performance status.


CONCLUSIONS
Adding antithymocyte globulin and thiotepa to the conditioning regimen prevents rejection of extensively T-cell-depleted bone marrow. Even in the complete absence of GVHD, the leukemia relapse rate is not higher than in unmanipulated transplants.
Aversa
F
F
BMT Program, Section of Hematology and Clinical Immunology, University of Perugia, Italy. aversa@unipg.it
Terenzi
A
A
Carotti
A
A
Felicini
R
R
Jacucci
R
R
Zei
T
T
Latini
P
P
Aristei
C
C
Santucci
A
A
Martelli
M P
MP
Cunningham
I
I
Reisner
Y
Y
Martelli
M F
MF
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D016465:Bone Marrow Purging; D016026:Bone Marrow Transplantation / Q000401:mortality; D002648:Child; D018572:Disease-Free Survival; D005260:Female; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000517:prevention & control; D006801:Humans; D007948:Leukemia, Monocytic, Acute / Q000628:therapy; D007951:Leukemia, Myeloid / Q000628:therapy*; D015470:Leukemia, Myeloid, Acute / Q000628:therapy; D015479:Leukemia, Myelomonocytic, Acute / Q000628:therapy; D015473:Leukemia, Promyelocytic, Acute / Q000628:therapy; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000628:therapy*; D012008:Recurrence; D013601:T-Lymphocytes