Allogeneic hematopoietic stem cell (HSC) transplantation is an established curative therapy for many severe blood diseases [1] that is carried out more than 50,000 times worldwide each year [2]. HLA-matched unrelated donors are an important HSC source, especially when no young HLA-identical family donor is available [3,4]. Therefore, large unrelated donor registries have been established in many countries [5] to account for the immense variability of the HLA system [6]. These registries work closely with donor centers, whose main tasks, alongside creating public awareness, include donor recruitment and administration.

DKMS was founded as a German donor center in May 1991 when only about 3000 donors were registered in Germany. By the end of 1991, DKMS had recruited around 68,000 donors. Today, DKMS operates donor centers in 7 countries with a total of 12.2 million registered donors and a multinational donor registry. DKMS plays an important role in the international system for the provision of HSC products from unrelated donors. In 2022, 57.5% of all cross-border HSC products (peripheral blood stem cells and bone marrow) worldwide, i.e. products in which donor and patient were from different countries, originated from donors registered with DKMS [7].

In this article, we first provide a brief overview of the international system of national donor registries and associated donor centers and the successes it has achieved. We then turn to our main subjects, the DKMS donor centers and the DKMS registry, and describe important aspects of their work.