Comparative Single-Center Analysis of Hematopoietic Cell Transplantation From Unrelated Umbilical Cord Blood or Haploidentical Related Donor or Mismatched Unrelated Donor in Patients with Hematologic Malignancies

Abstract 4535

One of the truly revolutionary advances in hematopoietic cell transplantation (HCT) is the increasingly successful use of alternative donors, as only 1/4 of patients who require an allogeneic hematopoietic cell transplant will have a HLA-matched sibling donor. A substantial proportion of the need has been met by HLA-matched volunteer unrelated donors, but an unmet need still exists, particularly for people who need a more immediate source of hematopoietic cells in China. Thereby, three alternative graft sources, umbilical cord blood (UCB), haploidentical (haplo) related donor, and mismatched unrelated donor (MMUD) are available.

We report a retrospective analysis of 95 patients with hematologic malignancies who received umbilical cord blood transplantation (UCBT) as a primary unrelated stem-cell source (n=20), or haploidentical (haplo) related donor (n=46), or mismatched unrelated donor (MMUD) (n=29), compare the days of hematopoietic reconstitution & engraftment, and rate of acute graft-versus-host disease (GVHD), and overall survival (OS). The average days of hematopoietic reconstitution (WBC >1.0*10E9) among UCBT recipients were significantly longer than those among haplo/MMUD recipients,(19.77 in UCBT,13.86 in haplo and 11.97 in MMUD, p<0.001). Whereas the average days of full engraftment (STR >95%) among haplo recipients were longer than those among UCBT/MMUD recipients,(24.85 in haplo, 19.29 in UCBT and 20.54 in MMUD, p=0.028). Multivarite analysis demonstrated no apparent differences in the rate of II-IV aGVHD (45% in UCBT, 41.3% in haplo and 55.2% in MMUD, p=0.498), so as to the rate of III-IV aGVHD (30% in UCBT, 41.3% in haplo and 17.2% in MMUD, p=0.543). Overall survival at 2 years was 75% in UCBT, 63% in haplo and 84% in MUUD (p=0.049), and the TRM was 29.4% in UCBT, 39.4% in haplo and 19.2% in MMUD (p=0.245).

It shows that UCB is associated with decreased II-IV aGVHD, but hematologic recovery is slow. Haplo HCT is characterized by donor availability for transplantation and post transplant adoptive cellular immunotherapy, but may be complicated by a high transplantation related mortality (TRM). A MMUD transplant may also be an option, but GVHD may be of greater concern. These data gives us some suggestion for using donor availability to decide on the best option for each individual patient.