Antithymocyte Globulin Improves the Survival of Patients with Myelodysplastic Syndrome Undergoing HLA-Matched Unrelated Donor and Haplo-Identical Donor Transplants

Background: Significant advances have been achieved in the outcomes of patients with myelodysplastic syndromes (MDS) after both HLA-matched sibling donor transplants (MSDT) and non-MSDT in the past few years, the latter including HLA-matched unrelated donor (MUDT) and haplo-identical donor transplants (HIDT).

Methods: We retrospectively analyzed the data of 85 consecutive patients with MDS who received allogeneic HSCT between Dec 2007 and Apr 2014 in our center. These patients comprised 38 (44.7%) who received MSDT, 29 (34.1%) MUDT, and 18 (21.2%) HIDT.

Results: The median follow-up was 30.0 months. Over all, the median overall survival (OS) was 60.2 months and the probabilities of OS at the first, second and fifth year were 63%, 57% and 48%, respectively. Median OS post transplant (OSPT) was 57.2 months and the probabilities of OSPT at the first, second and fifth year were 58%, 55% and 48%, respectively. Relapses occurred in 16 patients (18.8%), and the cumulative incidence of relapse at the first, second and third year were 14%, 23% and 27%, respectively. The survival of patients receiving non-MSDT was superior to that of MSDT, median OSPT being 84.0 months and 23.6 months, respectively (P=0.042);

And the similar result was observed when we analyzed the OS of patients who underwent non-MSDT or MSDT (median OS: 120 months vs. 27.0 months; P=0.028). We also found that using antithymocyte globulin (ATG) in conditioning regimens significantly improved survival after non-MSDT, with better OS and OSPT (P=0.016 and P=0.025). Furthermore, we compared OS or OSPT of patients who received non-MSDT with ATG (n=38) and MSDT without ATG (n=37). Our results showed that using ATG in conditioning regimen significantly improved survival of non-MSDT, with better OSPT (median OS: 84.0 months vs. 23.0 months; P=0.026) and OS (median OS: 120 months vs. 25.1 months; P=0.016).

Conclusions: These data suggest that, non-MSDT could be a valid alternative when MSDT is not available, and ATG may improve the survival of MDS patients after non-MSDT.