Comparative retrospective analysis of cord blood transplantation with ATG-containing conditioning regimens and haploidentical stem cell transplantation: similar survival outcomes with reduced incidence of GVHD.

Background: Cord blood (CB) is widely used in treating haematologic disorders due to its broad availability, tolerance to significant histocompatibility antigen disparities, and low incidence of chronic graft-versus-host disease (cGVHD). The cord blood transplantation (CBT) with anti-thymocyte globulin (ATG)-containing conditioning regimens shows promise in this regard.

Methods: We conducted a retrospective review of data from patients who underwent CBT at our centre from August 2003 to December 2022. Patients undergoing CBT with ATG were matched with those who received HLA-haploidentical haematopoietic stem cell transplantation (haplo-HSCT). Propensity score matching (PSM) was utilized to form 105 matched pairs (140 patients) for comprehensive trial analysis.

Results: The cumulative incidence of neutrophil and platelet engraftment was significantly lower in the CBT group. Patients in the CBT group exhibited significantly lower incidences of grade II-IV acute GVHD (aGVHD) and cGVHD compared to the haplo-HSCT group (8.57% vs. 29.52%,  = 0.012; 20% vs. 39.05%,  = 0.031). The overall survival (OS) rate for the CBT and haplo-HSCT groups showed no significant difference. In patients with leukaemia, the CBT cohort showed better OS, GVHD-free and relapse-free survival (GRFS), as well as a lower incidence of disease relapse, although there was no statistical difference.

Conclusion: Our single-centre retrospective long-term follow-up investigations indicated that although the implantation rate of CBT is lower than that of haplo-HSCT, patients undergoing CBT with ATG-containing conditioning regimens may have a comparable overall survival with a lower risk of GVHD compared to those undergoing haplo-HSCT.