Long-term results of a pilot study evaluating hyperbaric oxygen therapy to improve umbilical cord blood engraftment

Clinical Progress and Preclinical Insights Into Umbilical Cord Blood Transplantation Improvement

The application of umbilical cord blood (UCB) as an important source of hematopoietic stem and progenitor cells (HSPCs) for hematopoietic reconstitution in the clinical context has steadily grown worldwide in the past 30 years. UCB has advantages that include rapid availability of donors, less strict HLA-matching demands, and low rates of graft-versus-host disease (GVHD) versus bone marrow (BM) and mobilized peripheral blood (PB). However, the limited number of HSPCs within a single UCB unit often leads to delayed hematopoietic engraftment, increased risk of transplant-related infection and mortality, and proneness to graft failure, thus hindering wide clinical application. Many strategies have been developed to improve UCB engraftment, most of which are based on 2 approaches: increasing the HSPC number ex vivo before transplantation and enhancing HSPC homing to the recipient BM niche after transplantation. Recently, several methods have shown promising progress in UCB engraftment improvement. Here, we review the current situations of UCB manipulation in preclinical and clinical settings and discuss challenges and future directions.

Cognitive functioning of older adults prior to hematopoietic stem cell transplantation

Hematopoietic cell transplantation is increasingly used in older adults with hematological malignancies. Younger adult patients who undergo HCT have shown to commonly present with cognitive impairment and depression prior to transplant; however, little research has been done to understand the cognitive and emotional functioning of older adults undergoing HCT. This study aimed to investigate the rate of cognitive impairment in a retrospective sample of older adult HCT candidates prior to transplant using a comprehensive battery. Ninety-three patients over the age of 60 completed a neuropsychology test battery that assessed standard domains of cognitive and emotional functioning. Impairment was defined as z-scores = < -1.5 on at least two tests or a z score = < -2.0 on at least one test. Results indicated that over 68% of patients were impaired with nearly a third of the sample showing impairment in verbal learning and memory and approximately one fifth showing impairments in aspects of executive function, processing speed, and visual learning. Ten percent of the patients endorsed symptoms indicative of a clinical level of depression. Medical comorbidities nor depression predicted cognitive impairment. These findings suggest that older adults candidates for HCT are at risk for cognitive impairment prior to transplant and thus cognition should be a consideration when developing treatment plans.

Umbilical cord blood: The promise and the uncertainty

Unfortunately, many patients referred for hematopoietic cell transplant will not have a fully matched related donor, and finding matched unrelated donors through the registry may be difficult, especially if the recipient is not of Northern European descent [N Engl J Med 2014;371:339‐348]. Umbilical cord blood (UCB) has been an available graft source for hematopoietic cell transplant for more than 30 years, since the first UCB transplant was performed in the late 1980s [N Engl J Med 1989;321:1174‐1178]. UCB is readily available, has low immunogenicity, and does not require as strict of human leukocyte antigen (HLA) matching compared to other graft sources [N Engl J Med 2004;351:2265‐2275]. According to data from the Center for International Blood and Marrow Transplant Research (CIBMTR), an estimated 500 patients in the US will have received a UCB transplant in 2018. Since 2014, haploidentical transplants have surpassed UCB transplants performed in the United States (CIBMTR Summary Slides, 2018, available at https://www.cibmtr.org). Increased use of haploidentical transplants has brought to light concerns about UCB transplants, including delayed engraftment and graft failure, increased nonrelapse mortality, increased infection risk, and UCB acquisition costs [Lancet Oncol 2010;11:653‐660; Biol Blood Marrow Transplant 2019;1456‐1464]. These concerns will need to be addressed for UCB to remain a viable option as a graft source for hematopoietic cell transplant. Other promising therapeutic benefits for UCB, in addition to hematopoietic cell transplant, is its use in regenerative medicine and immune modulation, which is currently being evaluated in ongoing clinical trials.