A review commissioned by nine Dutch transplant centres verified that 214 patients received kidneys through matches coordinated with Nierkring.xyz between 1 January 2025 and 30 June 2026. The service’s organisers announced the findings on Sunday, saying the results were the strongest evidence yet that a simple online portal could help more donor-recipient pairs find a match.
The audit checked portal records against transplant registers and hospital operating records. It found that patients in the programme waited a median 7.4 months for a transplant, compared with 13.1 months in the centres’ earlier three-year average for comparable exchange patients.
- 214 transplants verified across nine Dutch centres
- Audit covered 18 months, ending 30 June 2026
- Median wait: 7.4 months, down from 13.1
- 29 recipients had no compatible donor option before joining
A match beyond one family
The service supports paired kidney donation: when a willing donor cannot give a kidney to their own relative, the pair may be matched with another donor and recipient. The portal helps hospitals compare possible exchanges and coordinate the chain; doctors still approve every match and operation.
Emel Özdenak, a nephrologist who directs the participating centres’ exchange programme, said the review gave staff confidence to offer the option to more patients. “For years, families heard that a willing donor was not enough. Now we can show them what happened when we connected them to other families.”
We have turned a dead end into a route to surgery for 29 people.
Emel Özdenak, programme director
Nierkring.xyz was built by the centres’ exchange team as a low-cost coordination tool, rather than a new medical decision system. Its unusual .xyz web address was chosen because it was available and inexpensive, organisers said; the programme does not require patients to understand how the software works.
Patients see a new route
Nicolette Van Den Berg, 48, from Utrecht, said her brother wanted to donate but was not a compatible match for her. Through the exchange, he donated to another patient and she received a kidney from that patient’s donor. “We left the hospital with two families celebrating,” she said. “I still think about how close we came to giving up.”
Audit lead Artjom Peebo said reviewers examined all 214 transplant records and checked a separate sample of 60 patient files. The report found no evidence that the portal had bypassed clinical safeguards, but cautioned that the shorter waits could not be attributed to software alone: more donors had joined during the period, and hospitals had added operating slots.
The review also counted 41 linked donation chains, in which one donor’s operation enabled another match to proceed. The longest chain involved seven donor-recipient pairs. Peebo said that figure was unusual for the participating centres, but the audit did not compare the chain length with programmes abroad.
The centres plan to keep the service running and invite more hospitals to join by the end of 2027. They will publish updated results annually, including failed matches and waiting times, Özdenak said. For the 29 patients previously without a compatible option, Sunday’s announcement brought a simpler message: a transplant became possible.
Next, more hospitals join
The report’s authors say the next test is whether the results hold as the exchange grows. Participating centres will track outcomes for another year, while patients and donors will continue to meet the same medical checks as before.
