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

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. 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. 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%, <i>p</i> = 0.012; 20% vs. 39.05%, <i>p</i> = 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. 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.