Multi-hospital kidney exchange in Brazil

An article in Floha de S. Paulo, tells of the first inter-hospital kidney exchange in Brazil:

 Transplante renal pareado amplia opção para pacientes que têm doador, mas não podem receber o rim  by Claudia Collucci

English translation:
Paired kidney transplant expands options for patients who have a donor but can't receive the kidney

https://www1.folha.uol.com.br/equilibrioesaude/2026/06/transplante-renal-pareado-amplia-opcao-para-pacientes-que-tem-doador-mas-nao-podem-receber-o-rim.shtml

Article summary: 

For the first time in Brazil, two transplant centers in different cities carried out a paired kidney donation — swapping incompatible living donors so each recipient gets a compatible kidney from someone else's donor instead. The initiative was led by Hospital das Clínicas at USP's medical school (HCFMUSP) in São Paulo and Santa Casa de Juiz de Fora in Minas Gerais.

The surgeries happened simultaneously at both hospitals — a donor from São Paulo traveled to Juiz de Fora to donate to the Minas Gerais recipient, while the donor from Minas Gerais went to Hospital das Clínicas in São Paulo to donate to the São Paulo patient. 

the two hospitals use an internationally developed (U.S.-built) platform that cross-references immunological traits, body size, and donor kidney quality to identify the best-matching combinations — this is functionally the same kind of algorithm we've been discussing with NKR.

Brazil has no specific regulation for paired kidney donation under its National Transplant System, so the procedure currently proceeds only as research. 

 

HT: Dr. Gustavo Ferreira 

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Earlier:

Thursday, January 22, 2026

Kidney exchange in Brazil (a clinical trial)

Here's a video in which Mike Rees, the founder of the Alliance for Paired Kidney Donation (APKD) describes how (with the help of a grant from Stanford Impact Labs) the APKD is helping Brazilian transplant docs get kidney exchange going there. 

 Earlier:

Tuesday, February 27, 2024  Stanford Impact Labs announces support for kidney exchange in Brazil, India, and the U.S.

 Thursday, October 10, 2024  Kidney exchange in Brazil, continued (with pictures)

 

Program for the Workshop on Game Theory and Economic Applications, São Paulo, July 26-August 2

 Here's a high level overview of the program, which begins today.

And here's the detailed day by day program. 

 I'm expecting to speak on Wednesday, which looks to be a busy day:

 

 

4th International Workshop on Game Theory and Economic Applications, São Paulo, July 26-August 2

 My old friend, colleague and coauthor Marilda Sotomayor is presiding over a big game theory conference in São Paulo this coming week.

 Here are the first paragraphs of the announcement from the University of São Paulo:

USP brings together six Nobel laureates in Economics in an event on Game Theory

 The Faculty of Economics, Administration, Accounting and Actuarial Sciences of the University of São Paulo (FEAUSP) will host, between July 26 and August 2, 2026, the 4th International Workshop on Game Theory and Economic Applications (IWGTEA). The event, consolidated as one of the most important in the area, is organized by the renowned professor emeritus of FEAUSP, Marilda Sotomayor, a world authority in Theory of Matching Markets.

The workshop will bring together six Nobel laureates in Economics. In person, FEAUSP will receive Paul Milgrom (Nobel 2020), Roger Myerson (Nobel 2007) and Alvin Roth (Nobel 2012). Laureates Robert Aumann (Nobel 2005), Robert Wilson (Nobel 2020) and Eric Maskin (Nobel 2007) will participate online. It will be a rare opportunity to translate how seemingly abstract mathematical ideas influence markets, governments, and everyday decisions.

In addition to the Nobel laureates, the body of keynote speakers includes important names such as Gabrielle Demange (Paris School of Economics), Ehud Kalai (Northwestern University), Hervé Moulin (University of Glasgow) and the Brazilian Aloísio Araújo (IMPA/FGV). There will also be a plenary session with Professor Marilda Sotomayor, who shared with Alvin Roth, in 1990, the authorship of the book "Two-Sided Matching: A study in game-theoretic modeling and analysis".


 

Nobel Prize in Economics Alvin Roth and professor Marilda Sotomayor (FEAUSP)
Photo: personal archive
 

Unlike traditional congresses, the IWGTEA is structured as a "workshop and school", focusing on the training of new researchers. "The idea is aimed at the interaction of students with the most renowned researchers in game theory", explains Professor Marilda Sotomayor. According to her, the main objective is to provide students with direct contact with the minds that shaped the modern economy. The expectation is that the workshop will attract 250 participants with more than 100 students from different parts of the world. 

... 

 Conference location: Av. Prof. Luciano Gualberto, 908 - Butantã, São Paulo - SP, 05508-010 

Schedule: https://www.iwgtea.fea.usp.br/ 

 

 

Auction markets for compute capacity as a pathway to building AI

 Dr. Silvia Console Battilana who partnered with Paul Milgrom to found the auction consulting firm Auctionomics, writes about markets for compute capacity as an aid to developing AI.

The Missing Market We Need To Win The AI Race
By Silvia Console Battilana,Forbes Councils Member.
for Forbes Business Council COUNCIL POST | Membership (fee-based) 

"In 2025, the global artificial intelligence market was valued at nearly $300 billion. By 2034, it’s projected to grow to almost $2.5 trillion. Demand for AI services is soaring and AI providers are racing to keep up. Behind them, suppliers of “compute”—the chips and data centers that power AI—are scrambling to expand capacity.

"So, what can the compute market do to enable this growth?

 ...

"There’s another drag on AI growth, and it’s one that I’ve seen before in my work designing markets for radio spectrum, energy and other limited resources: inefficient use of existing capacity. I believe the key to unleashing AI’s potential is not just to build more, but to use what we already have more productively.​

...

"Speeding up our AI highways will require addressing problems with existing compute markets. And one of the primary issues is that we treat all demand for compute the same. Some large compute jobs, including training runs for new AI models, are like tractors that move slowly and take up multiple lanes. These jobs require large quantities of compute but can be completed anytime. They could run overnight without losing value. Real-time AI queries and time-sensitive regressions, on the other hand, are like race cars. Their value depends entirely on speed. If they’re late, they’re worthless.

...

"We can build more lanes on the highway, but in my experience, that tends to be more costly than adding traffic lights and congestion pricing. A well-designed market should create incentives to guide when different compute jobs run. Through real-time spot markets, urgent jobs could pay more for capacity exactly when they need it. Through forward-looking futures markets, large but flexible jobs could secure low prices in advance. "

Kidney exchange in Germany can draw on the experience in other countries

 Here's an editorial arguing that as the recently legalized kidney exchange in Germany is implemented, attention should be paid to the controversies that have been encountered and addressed elsewhere, including those about non-directed donors, and the governance and transparency of transplant decisions.

 Benning L, Lu W, Budde K , Josephson, M.  Germany’s move toward kidney paired exchange and non-directed donation: governance lessons from abroad, Kidney International Reports, 2026 

"In 1986 F.T. Rapaport outlined a core idea behind kidney paired exchange: that a registry can coordinate incompatible donor-recipient pairs so that incompatibility becomes a solvable matching problem rather than a barrier to transplantation1. Today, forty years later, Germany is on the verge of making that coordination legally possible. In October 2025, the German federal cabinet approved a draft amendment to the Transplantation Act that would enable kidney paired exchange and non-directed anonymous living kidney donation, while strengthening donor protection and establishing the legal basis for a national program with a central matching function. If operationalized, Germany would move from a restrictive framework for living kidney donation, historically tied to a strict requirement of a close relationship between donor and recipient, toward a governance model that supports kidney exchange and donor chains at scale.

"This moment is internationally relevant because Germany now faces the same policy questions that have shaped kidney paired exchange implementation elsewhere. The impending change creates an opportunity to learn from other countries on key issues, including who should govern a registry, which safeguards ensure legitimacy, how to balance privacy and transparency regarding organ quality, and how to promote access without risking commercialization. Rather than being mere technical considerations, these questions are constitutive for the legitimacy and public trust required for kidney paired exchange to function as a public good. 

"Early debates about living kidney donation repeatedly straddled suspicion and admiration. In the 1970s, living non-related and particularly non-directed donors were sometimes portrayed in medical discourse as psychologically unstable or even pathological, raising concerns about whether such donors should be permitted to proceed2,3. 

...

" History offers two more lessons: (i) Donor protection and respecting donor agency are not mutually exclusive: psychosocial assessment, independent counseling, and rigorous consent procedures can reduce coercion and misunderstanding while still recognizing donors as autonomous agents making a deliberate moral choice. (ii) Public legitimacy is fragile and easily lost: If suspicion dominates, programs risk being viewed as illegitimate or unfair. If, on the other hand, enthusiasm and implementation moves faster than safeguards, programs risk scandal, backlash and, ultimately, lose public support. Germany’s 2012 transplant scandal, involving the manipulation of patient data to improve waiting-list positions, offers a cautionary example of how deficits in transparency and accountability can erode trust in transplantation more broadly and disrupt an entire program4."

##########

 There are many reviews of the international experience.  Below is a recent one from physicians at Erasmus University in the Netherlands:

Stijn C. van de Laar, Hidde A. de Heus, Annelies E. de Weerd, Matthijs F. Klaassen, Robert J. Porte, Robert C. Minnee Frank J.M.F. Dor, A Comprehensive Review of Strategies to Advance Kidney Exchange Programs and Optimize Effectiveness and Outcomes, Kidney International Reports, Volume 11, Issue 7, July 2026, 106539

"Living donor kidney transplantation (LDKT) offers superior graft survival and cost-effectiveness compared with deceased donor transplantation (DDKT), yet the availability of immunologically compatible living donors limits its reach. Kidney exchange programs (KEPs) can overcome these barriers by matching incompatible pairs through paired exchanges, domino chains, and nonsimultaneous extended altruistic donor (NEAD) chains. This review summarizes the evolution and current landscape of national and international KEPs. We examine operational challenges (cold ischemia time [CIT], logistical coordination, algorithmic fairness, and ethical and regulatory heterogeneity) and explore innovations in matching algorithms, international kidney exchange debates, and machine perfusion technologies. We conclude by proposing strategic priorities to optimize capacity, equity, and outcomes in future kidney exchange efforts. " 

####### 

Earlier: 

Friday, March 27, 2026 Germany legalizes kidney exchange !!

Surrogacy: a political scandal in Germany, and fertility tourism around the world

 Here's a story in the NYT, covering an uproar that's been in the German newspapers for a week or so now.  A leader in the German governing coalition announced on social media that he and his husband had welcomed a new baby into their family, born via surrogacy in the U.S.  But surrogacy in Germany is not legal, so this was a "for me but not for thee" hypocrisy moment there. (In general it's hard to ban effectively something that is legal in other jurisdictions: someone could write a book about that.)

Uproar Over Surrogate Baby Prompts German Official’s Sudden Resignation
Jens Spahn, a top leader of Chancellor Friedrich Merz’s party, resigned his post after announcing that he had a baby by surrogate, which is illegal in Germany.   By Jim Tankersley

"Mr. Spahn, 46, the leader of the party in Parliament, is a former federal health minister who has forged deep ties to the Republican Party under President Trump, including attending the 2024 Republican National Convention.

...

"Mr. Spahn stirred national outcry this week when he announced, on social media and in the tabloid paper Bild, that he and his husband, Daniel Funke, had become fathers to a son via a surrogate in the United States.

"Surrogacy is prohibited under German law. Mr. Spahn had defended that ban throughout his career, including as health minister.

"The birth announcement brought immediate cries of hypocrisy from across the political spectrum, including in Mr. Spahn’s own party. Some regional leaders of the Christian Democrats demanded his ouster. News outlets teemed with outrage. 

...

"Mr. Spahn defended himself, essentially, on a technicality: German law does not punish parents who use surrogates abroad. He told a podcast interviewer he had struggled with the decision but chose to prioritize his family." 

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Here's a related story: German couples in need of surrogacy are not the only ones, and the US is not the only destination.

The Guardian reports:

Rise in overseas surrogates ‘increases risk of stateless babies’
Calls grow for global regulation as rising numbers of westerners use surrogates in countries with different laws  by Jessica Murray and Rachel Hall

"The rise in the use of surrogates abroad is leaving more babies at risk of becoming stateless, experts have said, amid growing calls for urgent global regulation of the practice.

"The warning follows the suspension of a 15-year effort by The Hague Conference on Private International Law (HCCH) to establish a global surrogacy convention, which was paused due to divisions among member states. 

...

"UK surrogacy agencies argue that an outdated legal framework at home is pushing couples to seek surrogates abroad, where regulations to protect surrogates from exploitation can be less robust or do not exist at all. Anti-surrogacy campaigners say the practice is fundamentally abusive in all cases and are pushing for a global ban.

"Prof Michael Hellner, who chaired the HCCH working group, said hugely differing opinions on the ethics of surrogacy between the member states involved meant the project to create a global framework on legal parentage in surrogacy cases had proved impossible.

...

"Experts said statelessness could happen in cases where a country does not automatically grant nationality to a child born there, and where surrogacy is not legally recognised in either the country of birth or the child’s final destination.

"Hellner said the project had proved difficult when some countries were “violently opposed to anything that could be seen as legitimising surrogacy, which they think is a violation of human rights and dignity”. 

...

"Most of these children were born abroad, mostly in the US, Ukraine, Nigeria, Georgia, Colombia and Mexico. British people using surrogates abroad to have babies are forced to apply to the UK family courts for a parental order to become the legal parents of their child and, in some cases, also need to apply for British citizenship for the child." 

Are vouchers appropriate for hard-to-match patient-donor kidney exchange pairs?

 A recent letter from Mayo Clinic transplant providers raises concerns related to bad outcomes when some patient-donor pairs are separated (the donor donates before the intended recipient is matched to a donor), but the intended recipient is hard to match.

Donor Mentoring in Private Kidney Paired Donation Programs: The Need for Transparency and Accountability by Tayyab S. Diwan, Pooja Bhudiraja, Shennen Mao, and Carrie Schinstock, Transplantation 110(7):p e1555-e1556, July 2026. | DOI: 10.1097/TP.0000000000005764 

"it is important to recognize that some KPD organizations, such as the National Kidney Registry, operate as private organizations (POs) with distinct governance structures, priorities, and commercial interests. These objectives may not always fully align with those of transplant centers or the broader transplant community, potentially creating gaps in transparency and accountability within a process that directly affects donors and recipients.

"We recently encountered a concerning example that illustrates the ethical tensions inherent when donor mentors are employed by private KPD organizations. ... During a routine text message check-in, the mentor initiated a discussion promoting voucher donation, emphasizing that voucher donors receive priority within the system.  

...
"The donor described the interaction as uncomfortable and “pushy,” and subsequently contacted our transplant center for guidance. Notably, the communication focused on system-level benefits and prioritization metrics but did not explore critical clinical and ethical considerations specific to this donor-recipient pair.

"The discussion was insufficiently individualized and appeared framed toward a preferred outcome. The donor’s preferences and the potential downsides of voucher donation were not explored. The mentor did not ask how the donor would feel if they proceeded with voucher donation and their intended recipient never received a transplant. The discussion lacked any reference to recipient factors that could influence the advisability of voucher donation, including sensitization or recipient comorbid conditions. There was also no discussion about why KPD was being used. Often the donor can donate directly to a recipient (eg, compatible pair), but may decide to enter a KPD pool temporarily to see whether the recipient could receive a transplant with improved size or HLA matching. Finally, the average wait times for a recipient to receive a transplant after voucher donation were not mentioned.

"This interaction raises concern about whether the mentor’s guidance was fully centered on the donor-recipient pair or instead influenced, even indirectly, by organizational incentives to increase voucher participation. When donor mentors are employed by entities that operationally benefit from particular forms of donation, even well-intentioned communication can create perceived or actual conflicts of interest. Transparency regarding these structural incentives, along with a clear commitment to individualized donor-centered mentoring, is essential to maintaining ethical integrity in these situations.

...

"As stewards of living donor trust, the transplant community must ensure that innovation proceeds with appropriate oversight. Any perception that donor education or support is influenced by business interests risks eroding public confidence in living donation programs, with potentially far-reaching consequences that could discourage future donors." 

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 Here's an article on NKR from the NYT that discusses its particular voucher program (and also its finances):

How One Father Created an Organ Empire: The National Kidney Registry has matched thousands of kidney donors with recipients. It has also paid millions of dollars to a company owned by its founder.
By Danielle IvoryGrace Ashford and Robert Gebeloff
Dec. 27, 2025 

 "One of N.K.R.’s most innovative policies, many doctors said, is known as voucher donation: Donors can choose to give their kidneys immediately, in exchange for organ vouchers their loved ones redeem later.

"This arrangement has helped N.K.R. expand its pool. But vouchers add risk for donors giving on behalf of hard-to-match patients. They might go through surgery months or even years before their loved ones get a match. Matches are especially unlikely, doctors said, for “very highly sensitized” patients who carry antibodies likely to reject a transplant.

...

" many doctors said that given N.K.R.’s relatively small size, these rare patients would be better served waiting for a match before their loved ones donate.

"“We definitely recommend that they not go with a voucher,” said Dr. Miklos Molnar, the medical director of the kidney transplantation program at the University of Utah, which works with N.K.R.

"Dozens of highly sensitized patients who are also on kidney dialysis have waited a year or more after their loved ones donated, according to N.K.R. quarterly reports since 2022. At least three waited more than four years, and one for seven years.

"Doctors told The Times that they knew of some patients who became too sick or died before they redeemed their vouchers."

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Here's a a discussion of the earliest exploration of unpaired donation that I know of:

Sunday, September 13, 2020

A proposal for non-simultaneous kidney exchange in pairs and chains and with deceased donors...