Late Onset Acute GVHD (late aGVHD) after Allogeneic Hematopoietic Stem Cell Transplantation (HCT)

Abstract

associated with reduced relapse (HR 0.64 in F->M and 0.59 in M->F, P<0.01 in each), while no impact of sex-mismatch on relapse was observed in the MAC or RIC groups (Fig 1). Finally, in the TLI-ATG group, sex-mismatched transplant was significantly associated with superior OS (HR 0.69 in F->M, P¼0.037; HR 0.61 in M->F, P¼0.014), while F->M transplant was significantly associated with inferior OS in the MAC group (HR 1.59, P¼0.018) and no improvement in OS in the RIC group (HR 1.31, P¼0.36) (Fig 2). In the TLI-ATG group, the benefit of sex-mismatched HCT on OS seems due to the reduced relapse rate. We previously reported HY-Ab response post-HCT was associated with chronic GVHD as a representative of allo-Ab response (Nakasone et al. ASH 2013). We then hypothesized that HY-Ab response 3m post-HCT could predict reduced relapse in F->M HCT with TLI-ATG. Relapse incidence at 2 years post-HCT was higher in the recipients who had no HY-Ab response at 3m post-HCT vs. those who did (49% vs. 26%, P¼0.037, Fig 2). Multivariate analysis corroborated that the detection of HYantibodies 3m post-HCT was significantly associated with reduced relapse in F->M HCT with TLI-ATG [HR 0.29, P¼0.039]. Conclusion: We conclude that the benefits and risks of sexmismatch differ according to conditioning intensity/strategy, and is the first reported evidence that sex-mismatched transplant might preferably be selected in TLI-ATG, while avoided in MAC transplantation.