The Transplant Outcomes of a 10/10 Matched Unrelated Donor (MUD) Stem Cell Transplant (SCT) Is Similar to a HLA Identical Related Donor (RD) Transplant.

Allogeneic SCT is a potential curative treatment for many hematological malignancies. Unfortunately, approximately 70% of patients who may benefit from an allogeneic SCT can not find a HLA identical related donor. Through National Marrow Donor Program, about 60-70% patients will be able to identify a suitable donor for transplant. However, prior studies suggested that MUD-SCT was associated with increased transplant related morbidity and mortality when compared with RD-SCT. Hence, many hematologists/oncologists were hesitant to recommend a MUD-SCT even when a matched related donor is not available. We hypothesized that through optimal HLA typing and using a 10/10 molecularly matched unrelated donor, the outcomes for a MUD-SCT will be similar to RD-SCT.

Beginning in 2004, we adopted a new policy in HLA typing and all patients and donors will be tested for HLA: A, B, C, DR, and DQ using molecular techniques. Here, we report the outcomes on 24 consecutive patients who revived a 10/10 MUD-BMT at our institution.

Between February, 2004 and April, 2008, 24 patients (8 males & 16 females) with various hematological malignancy and life threatening hematological disorders underwent a 10/10 molecularly matched MUD-SCT at Rush University Medical Center. Median age at SCT was 43 (range 18-67). Diagnoses included acute myeloid leukemia:11, myelodysplasia:3, non-hodgkin lymphoma:3, chronic myeloid leukemia:2, acute lymphoblastic leukemia:2, severe aplastic anemia:2 and hodgkin lymphoma:1. While 9/24 (38%) has early disease, 15/24 (62%) had advanced disease at SCT. All patients received a myeloablative conditioning regimen. Four patients (4/24, 17%) died before day 100 post-SCT from treatment related toxicity; all 4 pts > 55 years old. The 1-year survival was 62.5% with a minimal follow-up of 1 year for surviving patients. At last follow-up, 9 patients survived greater than 3 years post-SCT. The cumulative incidences of acute GVHD Grades ≥ 2 and 3 - 4 were 42% and 13% respectively.

We conclude that the transplant outcomes of 10/10 matched unrelated donor stem cell transplant appears similar to matched related donor stem cell transplant. Thus, matched related donor stem cell transplant should be considered for patients lacking a HLA identical donor whenever an allogeneic SCT is clinically indicated.

No relevant conflicts of interest to declare.