TRANSPLANTATION OF MARROW-CELLS FROM UNRELATED DONORS FOR TREATMENT OF HIGH-RISK ACUTE-LEUKEMIA - THE EFFECT OF LEUKEMIC BURDEN, DONOR HLA-MATCHING, AND MARROW CELL DOSE

Transplantation of hematopoietic stem cells from an HLA-compatible unr elated volunteer is an option for patients with acute leukemia lacking a family match. However, criteria for patient and donor selection and the most effective transplant procedures, including the number of hem atopoietic cells, remain to be defined. We tested factors influencing outcome of 174 patients with primary acute leukemia receiving non-T-ce ll depleted marrow from unrelated donors. Median patient age was 20 ye ars (range, 0.5 to 54 years). A multivariable analysis found that leuk emia in remission at the time of transplantation was associated with i mproved leukemia-free survival (relative risk [RR] of treatment failur e: 0.5, confidence interval [CI]: 0.3 to 0.7), and presence of blasts in the peripheral blood, as opposed to marrow involvement only or isol ated extramedullary relapse, was associated with impaired outcome (RR of treatment failure: 2.5, CI: 1.7 to 5.0). The use of donors with a l imited HLA-mismatch was associated with decreased leukemic relapse (RR : 0.5, CI: 0.3 to 0.9) but no improvement in leukemia-free survival co mpared with HLA-matched unrelated donors. Transplantation of a marrow cell dose above the median value of 3.65 x 10(8)/kg was associated wit h faster neutrophil (RR: 1.5, CI: 1.1 to 2.0) and platelet (RR: 4.5, C I: 2.7 to 7.5) engraftment, and decreased incidence of severe acute gr aft-versus-host disease (RR: 0.6, CI: 0.4 to 0.9). In patients transpl anted in remission, the use of a marrow cell dose above the median tra nslated into less nonleukemic death (RR: 0.2, CI: 0.1 to 0.4) and bett er leukemia-free survival (RR of treatment failure: 0.3, CI: 0.2 to 0. 6). Transplant in remission with a high dose of marrow cells was assoc iated with the best outcome in both children and adults. (C) 1997 by T he American Society of Hematology.