Safety of allogeneic umbilical cord blood infusions for the treatment of neurological conditions: a systematic review of clinical studies

Background aims: Umbilical cord blood (UCB) infusion is being investigated as a treatment for a range of neurological conditions, primarily because of its potent immunomodulatory effects mediated via paracrine signaling. Although initial research mainly utilized autologous UCB, allogeneic samples from a sibling or unrelated donor have now become more common. With the use of allogeneic UCB, questions have arisen surrounding the necessity for human leukocyte antigen (HLA) matching, preparative regimens and immunosuppressant drugs. To investigate the safety of allogeneic UCB for the treatment of neurological conditions and the impact of HLA mismatching and immunosuppresion, the authors conducted a systematic review of the safety of allogeneic UCB infusion for neurological conditions. Methods: A systematic review of published and gray literature was conducted to investigate the safety of allogeneic UCB infusions for neurological conditions. Results: Authors identified 10 studies using allogeneic UCB to treat autism spectrum disorder, cerebral palsy, stroke, traumatic brain injury and various other conditions. A total of 361 participants (with at least 442 UCB infusions) received a range of HLA-matched/untyped allogeneic units and cell doses, with the majority not administered post-infusion immunosuppression. There were no reported serious adverse events definitely or probably related to the allogeneic UCB infusion, nor later potential complications such as graft-versus host disease or teratoma formation. Conclusions: Although variability between studies is high, the available data do not identify safety concerns with allogeneic UCB infusion for the treatment of neurological conditions, even with variable HLA matching or no immunosuppression. (c) 2021 International Society for Cell & Gene Therapy. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)