Genetic Findings of Potential Donor Origin following Hematopoietic Cell Transplantation: Recommendations on Donor Disclosure and Genetic Testing from the World Marrow Donor Association.

Following hematopoietic cell transplantation (HCT), recipients are subjected to extensive genetic testing to monitor the efficacy of the transplantation and identify relapsing malignant disease. This testing is increasingly including the use of large gene panels, which may lead to incidental identification of genetic and molecular information of potential donor origin. Deciphering whether variants are of donor origin, and if so, whether there are clinical implications for the donor can prove challenging. In response to queries from donor registries and transplant centers regarding best practices in managing donors when genetic mutations of potential donor origin are identified, the Medical Working Group of the World Marrow Donor Association established an expert group to review available evidence and develop a framework to aid decision making. These guidelines aim to provide recommendations on predonation consenting, postdonation testing of recipients, and informing and managing donors when findings of potential donor origin are identified in recipients post-transplantation. It is recognized that registries will have different access to resources and financing structures, and thus whenever possible, we have made suggestions on how recommendations can be adapted.

Favorable recovery profiles and good reliability among youngest unrelated stem cell donors supports lowering the minimum donor registration age.

INTRODUCTION: Younger donor age in hematopoietic cell transplantation has been associated with improved overall and disease-free survival. Safety data on peripheral blood stem cell (PBSC) and bone marrow (BM) donation is well established, including in the <18-year old age group in the related setting. In response, Anthony Nolan became the first stem cell donor registry to lower the minimum age for unrelated donors to 16-years. MATERIALS AND METHODS: This retrospective study reviewed unrelated donors donating PBSC or BM for the first time between April 2015 and October 2017 since adoption of the lowered recruitment age. Data were collected from registry electronic database and structured follow-up questionnaires. Primary outcomes were turnaround time from VT to donation, optimal cell yield achievement, and physical and emotional recovery. RESULTS: Out of a total of 1013 donors, there were no differences between the different age groups in proportion of donors achieving optimal CD34+ or TNC (PBSC and BM, respectively). There was no increased central line requirement for younger donors or increased emergency telephone support. Youngest donors were more likely to report physical recovery 2 and 7 days post-PBSC (P = .024 and P = .015, respectively) as well as an earlier emotional recovery (P = .001) and fewer physical symptoms 1 week BM donation (P = .04). CONCLUSION: This study shows that younger donors are as reliable as older donors, and have favorable recovery profiles without need for increased support at any stage of the donation, supporting Anthony Nolan recruitment strategy and offering reassurance to donor registries considering the same.