The Balearic Islands now have 7,609 people registered as potential bone marrow donors, as health authorities highlight a sharp increase in new registrations and the growing importance of donor-based transplants.

The figures were released for World Marrow Donor Day, which this year falls on Saturday, September 19, and aims to raise awareness of voluntary donation for patients who may need a hematopoietic stem-cell transplant.

More than 7,600 potential donors registered

There are currently 7,609 people registered as bone marrow donors in the Balearic Islands.

Their details are included in the Spanish Bone Marrow Donor Registry, known as REDMO, which is connected to international donor registries.

A donor registered in Spain can therefore potentially be identified as a match for a compatible patient not only in Spain but elsewhere in the world.

New registrations have increased sharply

The number of new people joining REDMO in the Balearics has risen significantly in recent years.

There were 44 new registrations in 2023.

By 2025, the figure had reached 545.

That means the number of new registrations in 2025 was more than twelve times the number recorded two years earlier.

The figures concern new registrations during each year, not the total number of people remaining in the registry.

Health authorities credit greater awareness

The Balearic Health Ministry says the growth is linked in part to stronger recruitment and information campaigns.

A multidisciplinary team involving hospital professionals and staff from the Blood and Tissue Bank has increasingly been involved in explaining the donation process and encouraging eligible people to consider joining the registry.

The aim is to make sure potential donors understand what registration involves before they provide consent.

Donating does not mean an immediate procedure

Joining REDMO does not mean that someone immediately undergoes a donation.

People initially become potential donors after completing the information and consent process and providing a blood or saliva sample for HLA typing, the testing used to assess compatibility.

Only if a donor is subsequently identified as a suitable match for a patient and remains medically eligible does the donation process move forward.

The registry works internationally

REDMO is part of an international network of donor registries.

The information is coded so that donor identity is protected, while compatibility data can be searched when transplant centres are looking for a suitable unrelated donor.

This international network is important because finding a compatible donor can be difficult, particularly for patients who do not have a suitable donor within their family.

Ninety-two transplants were carried out in 2025

The growth in donor availability comes alongside an increase in transplant activity in the Balearics.

A total of 92 hematopoietic stem-cell transplants were carried out in the islands during 2025.

Of these, 78 were performed at Hospital Universitario Son Espases and another 14 at Hospital Universitario Son Llàtzer.

Son Espases recorded a significant increase

Son Espases, the Balearic Islands' reference hospital for this activity, performed 78 transplants in 2025.

That was 17 more than the previous year, an increase of approximately 28%.

The strongest growth was recorded in allogeneic transplants, where the cells come from another compatible person.

Those procedures increased from 17 in 2024 to 38 in 2025, an increase of more than 120%.

Unrelated-donor transplants rose particularly sharply

Within the allogeneic category, transplants involving unrelated donors increased from nine in 2024 to 27 in 2025.

That represents a 200% increase.

The figures illustrate the importance of national and international donor registries in providing access to compatible stem cells for patients who do not have a suitable family donor.

Not all transplants use donor cells

There is an important medical distinction behind the headline figure of 92.

Of the 92 transplants performed in the Balearics in 2025, 54 were autologous, meaning the patient's own cells were used.

The other 38 were allogeneic, involving cells from a compatible donor.

For that reason, the broader and more precise medical term is hematopoietic stem-cell transplantation rather than assuming that every procedure involved a bone marrow donor.

Donor cells can come from different sources

People often use “bone marrow donation” as a general term, but hematopoietic stem cells can be collected through different procedures depending on the patient's needs.

The Organización Nacional de Trasplantes explains that potential donors are first registered and typed for compatibility. If a donor is selected, the medical team determines the appropriate method of collection.

In Spain, volunteer donors may therefore be asked to provide blood-forming stem cells through the method required by the patient's treatment.

Compatibility is the key factor

A large donor registry does not mean that every patient will find a match.

Human leukocyte antigen, or HLA, characteristics vary greatly between individuals.

This is why large national and international registries are important: increasing the number of potential donors increases the pool in which compatible matches can be sought.

The search can involve both REDMO and international registries connected to the global donor network.

Voluntary and altruistic donation

Bone marrow and hematopoietic stem-cell donation in Spain is voluntary and altruistic.

People who join the registry make a commitment to potentially donate to any compatible patient who needs a transplant, subject to the required medical assessments and the conditions governing the donation.

The registry therefore operates according to a principle of international solidarity rather than being restricted to particular hospitals or individual patients.

Patients who may benefit

Hematopoietic stem-cell transplants are used in the treatment of a range of blood-related diseases.

The Balearic Health Ministry specifically highlights patients with acute leukaemia, lymphoma and multiple myeloma among those who may benefit from this type of donation and transplantation.

The suitability of a transplant depends on the individual patient's medical condition and treatment plan.

Spain's donor registry is part of a much larger network

REDMO forms part of an international system that allows transplant centres to search for compatible volunteer donors across borders.

The Organización Nacional de Trasplantes says REDMO had 520,850 registered donors in Spain at the end of 2025.

The Spanish registry works together with the Fundación Josep Carreras and international donor databases to identify potential matches.

The role of hospitals and the Blood and Tissue Bank

Increasing the number of people on the registry depends not only on public awareness but also on the health system's ability to inform potential donors and process registrations.

Hospitals and the Blood and Tissue Bank in the Balearics are playing an increasingly important role in recruitment campaigns.

Health professionals provide information about the commitment involved and organise the initial compatibility testing needed to enter the registry.

World Marrow Donor Day highlights the need for more donors

World Marrow Donor Day is observed internationally to highlight the importance of volunteer stem-cell donors and the patients who depend on finding a compatible match.

The day provides an opportunity for donor registries and health organisations to explain how the system works and encourage eligible people to learn about registration.

For the Balearic Islands, this year's observance comes with a clear local message: the registry has grown considerably, but continued recruitment remains important.

How registration works in Spain

The first step is to receive detailed information about what becoming a donor involves.

A person who decides to proceed completes the relevant consent and registration documents and provides a sample of blood or saliva for HLA typing.

The results are entered into REDMO in coded form.

A person does not undergo an actual stem-cell donation simply by joining the registry.

What happens if a match is found?

If a donor is identified as potentially compatible with a patient, REDMO contacts the person and further medical assessments are carried out.

The transplant centre ultimately determines whether that donor is the appropriate match and whether the donation should proceed.

A donor may therefore be contacted some time after joining the registry, or may never be selected if no suitable match is found.

A growing number of donor-based transplants

The Balearic figures for 2025 show that allogeneic transplantation is becoming a larger part of the region's activity.

At Son Espases, allogeneic procedures increased from 17 to 38 in one year.

The rise was particularly marked among unrelated-donor transplants, which increased from nine to 27.

The trend makes the availability of compatible volunteer donors increasingly relevant to the region's transplant activity.

The figures reflect the whole Balearic Islands

The 7,609 registered donors are counted across the Balearic Islands rather than in a single municipality.

The transplant figures likewise cover procedures performed at the two hospitals providing this activity: Son Espases and Son Llàtzer.

For Ibiza and Formentera, potential donors are therefore part of the same regional and national registry used to search for compatible patients and donors.

Ibiza and Formentera are part of the same system

Residents of Ibiza and Formentera who meet the eligibility requirements can join Spain's national donor registry.

If they are later identified as a compatible donor, the matching and donation process is coordinated through the national system rather than being limited to the patient's or donor's home island.

This means that a donor from Ibiza could potentially help a patient elsewhere in Spain or another country.

The importance of unrelated donors

Family members are not always a suitable match for someone requiring a stem-cell transplant.

When no compatible family donor exists, transplant centres can search national and international volunteer registries.

The increase from nine to 27 unrelated-donor transplants at Son Espases during 2025 highlights the growing role of this international system in the Balearic Islands.

More registrations mean a larger potential pool

The rise from 44 new registrations in 2023 to 545 in 2025 represents a substantial increase in recruitment.

Each new registration adds another potential donor to the pool that can be searched when compatibility is required.

It does not mean that each newly registered person will eventually donate, because an actual donation only occurs if a compatible patient is identified and the donor remains eligible.

The registry depends on continued participation

The process also requires donors to remain contactable and medically eligible.

The Organización Nacional de Trasplantes describes registration as a significant commitment because a person who joins REDMO agrees to be available to donate to a compatible patient if they are eventually selected.

For that reason, health authorities stress the importance of understanding the commitment before joining.

A growing regional network

The Balearic Islands' 7,609 registered donors represent a growing pool for a system that extends beyond the archipelago.

At the same time, the 92 transplants carried out in 2025 demonstrate the scale of hematopoietic transplant activity taking place within the islands.

The combination of donor recruitment, hospital expertise and international registries allows patients to be assessed for potential matches through a much larger network than the local population alone.

The latest figures at a glance

Registered bone marrow donors in the Balearics: 7,609

New REDMO registrations in 2023: 44

New REDMO registrations in 2025: 545

Hematopoietic stem-cell transplants in the Balearics in 2025: 92

At Son Espases: 78

At Son Llàtzer: 14

Allogeneic transplants at Son Espases: 38 in 2025, compared with 17 in 2024

Unrelated-donor transplants at Son Espases: 27 in 2025, compared with nine in 2024

Autologous transplants in the Balearics in 2025: 54

A local increase with an international purpose

The growth in donor registrations in the Balearic Islands is part of a system whose purpose extends far beyond the archipelago.

Every person added to REDMO becomes a potential match for a compatible patient in Spain or another country.

The increase in registrations from 44 new donors in 2023 to 545 in 2025 therefore represents more than a local health statistic. It expands the pool available to a national and international search for compatible stem cells.

Continued awareness remains important

The Balearic Health Ministry is using World Marrow Donor Day to highlight the role of voluntary donors and the professionals who recruit and support them.

The latest figures show that registration has grown significantly and that transplant activity has also increased, particularly in procedures involving unrelated donors.

For patients waiting for a compatible stem-cell donor, the size and diversity of the international registry can be critical.