Haploidentical transplant for myelodysplastic syndrome: registry-based comparison with identical sibling transplant

Encouraging results from a small sample of patients with myelodysplastic syndrome (MDS) undergoing haploidentical donor (HID) hematopoietic stem cell transplantation (HSCT) must be extended. Furthermore, an algorithm derived from a comparison of the outcomes of HID and identical-sibling donor (ISD) HSCT must be established. Therefore, the outcomes of 454 MDS patients who underwent HSCT from HIDs ( n =226) or ISDs ( n =228) between 2003 and 2013 that were reported to the Chinese Bone Marrow Transplantation Registry were analyzed. Among the 3/6 HID ( n =136), 4–5/6 HID ( n =90) and ISD patient groups, the 4-year adjusted cumulative incidences of non-relapse mortality were 34, 29 and 16%, respectively (overall P =0.004), and of relapse were 6, 7 and 10%, respectively (overall P =0.36). The 4-year adjusted probabilities of overall survival were 58, 63 and 73%, respectively (overall P =0.07), and of relapse-free-survival were 58, 63 and 71%, respectively (overall P =0.14); pairwise comparison showed that the difference was only statistically significant in the 3/6 HID vs ISD pair. The data suggest that ISDs remain the best donor source for MDS patients while HIDs (perhaps 4–5/6 HID in particular) could be a valid alternative when an ISD is not available; human leukocyte antigen disparity had no effect on survival among the HID patients.