# The impact of the donors’ COVID-19 status on the outcomes of allogeneic hematopoietic stem cell transplantation: a multi-center retrospective study

## TL;DR

This study examines how the COVID-19 status of donors affects the outcomes of stem cell transplants, finding a higher risk of aGVHD when donors were positive for COVID-19.

## Contribution

The study identifies that donor COVID-19 positivity is an independent risk factor for acute graft-versus-host disease in allogeneic stem cell transplantation.

## Key findings

- Donor COVID-19 positivity was linked to higher grade II-IV aGVHD rates (55.6% vs. 10%).
- Graft collection and engraftment were not affected by donor COVID-19 status.
- Short-term survival rates were similar across all donor groups.

## Abstract

To explore the impact of donors’ COVID-19 status on allogeneic stem cell transplantation (allo-HSCT), we compared the transplant outcomes of 74 participants.

This multi-center retrospective study included nine participants receiving grafts from COVID-19 positive donors (CPD), 45 from COVID-19 experienced donors (CED), and 20 from COVID-19 naive donors (CND). We evaluated engraftment, complications, and survival rates among the three groups.

All apheresis procedures were successful with no significant differences in CD34+ cells or lymphocytes in grafts among the three groups. All patients achieved engraftment by day 30 post-HSCT. The incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 55.6%, 20%, and 10% in the CPD, CED, and CND groups, respectively (p = 0.024). Multivariate analysis indicated that COVID-19 positivity in donors at the time of apheresis was an independent risk factor for II-IV aGVHD (p = 0.020, OR = 12.159, 95% CI 1.783 -135.760). No differences were observed among the groups in terms of chronic GVHD, viral infection, or sinusoidal obstruction syndrome. The 6-month overall survival and disease-free survival rates were also similar among the three groups.

Our results suggest that the COVID-19-positive status of donors might not impact graft collection, engraftment, or short-term survival of allo-HSCT recipients but might increase the risk of aGVHD. Further research is needed to explore the influence of donors’ COVID-19 status on long-term complications and survival in allo-HSCT recipients.