COMPARISON OF ENGRAFTMENT IN RECIPIENTS OF MATCHED SIBLING OR UNRELATED DONOR MARROW ALLOGRAFTS

Bone marrow transplantation (BMT) from unrelated donors (URD) is being increasingly used as a treatment modality for patients with hematolog ical malignancy and graft failure. We hypothesized that use of unrelat ed donors with increased degrees of histoincompatibility, as determine d by standard serological techniques, would be associated with increas ed difficulty in achieving engraftment and more frequent graft failure . Engraftment was analyzed in 108 patients with hematologic disease wh o underwent BMT from a fully serologically HLA-matched unrelated donor (n = 40) or a partially serologically HLA-matcbed unrelated donor (n = 68). These patients were compared with 236 patients who received BMT from matched sibling donors (MSD group) over the same time period. Pr imary graft failure occurred in 5% of the MSD group, 6% of the serolog ically matched URD group and 15% of the partially serologically matche d URD group (p = 0.06). Univariate and multivariate analysis of factor s relating to primary graft failure showed the only significant variab le to be full or partial serological HLA-matching in the URD group. Se condary graft failure occurred in 0.7% of the MSD group, 15% of the se rologically matched URD group and 25% of the partially serologically m atched URD group (p < 0.0001). Univariate and multivariate analysis of secondary graft failure showed the only significant variable to be a related or unrelated donor. We conclude that primary graft failure is a significantly more frequent event in recipients of bone marrow from partially serologically matched URD than in recipients of MSD or fully serologically matched URD marrow. Seondary graft failure is significa ntly more frequent in recipients of fully or partially serologicaIly H LA-matched URD transplants compared with recipients of MSD transplants .