Background

Hematopoietic stem cell transplantation is a curative treatment for various high-risk diseases of the hematopoietic system. Transplantation from unrelated donors is the most widely used transplant source as many patients lack a matched sibling donor. The search unit of the Institute for Clinical Transfusion Medicine and Immunogenetics Ulm conducts unrelated donor searches for 23 clinics across Germany. In this analysis, we summarize the trends and improvements over the last 10 years.

Methods

The search database of the search unit in Ulm was queried for all searches between 01.01.2013 and 31.12.2022. We generated descriptive statistics with the aim to identify trends and changes over time using RStudio and R for Windows Version 4.1.3.

Results

A total of 11035 searches were performed. Search numbers increased from 1085 (2013) to 1196 (2022), which leads to an average increase of 1.4% per year (determined per linear regression). The proportion of highly urgent searches decreased from 25.5 to 17.1% per year. Match rates showed almost constant improvement from 2013 (10/10: 73.1%, 9/10 24.8%, 8/10 2.1%) to 2022 (10/10: 82.3%, 9/10: 16.8%, 8/10: 0.9%). In all years search success rates were greater than 95% (defined as at least one donor found that met minimum requirements of the transplant center). Search duration defined as time from initiation of the search until first donor is identified improved significantly between 2013 (mean 34d, median 15d) and 2022 (mean 17d, median 13d).

Conclusion

Increasing numbers of upfront high-resolution HLA-typed donors are available worldwide. The larger donor pool and the high quality of HLA-typing in registry donors led to substantial improvements in donor search, manifesting in better match rates and shorter search duration. This benefits patients in urgent need of an allogenic stem cell transplantation in Germany.

Offenlegung Interessenkonflikt:

No conflicts of interest are present