Teams from the Adult Nephrology-Renal Transplant Department at Hôpital Necker – Enfants malades AP-HP, Inserm, the Paris Institute of Transplantation and Organ Regeneration and Université Paris Cité, coordinated by Pr Alexandre Loupy and Marc Raynaud, have demonstrated that a new renal function equation without ethnic parameters could significantly improve the monitoring and management of kidney transplant patients.

This work was published on May 31, 2023 in the journal BMJ.

Kidney transplantation is the best option for people with end-stage renal failure, in terms of increasing life expectancy, improving quality of life, and reducing costs for society. In a context of organ shortage, transplant failures are exacerbating the growing number of people in kidney failure.

No renal function equation has been developed specifically for transplant patients, although this could enable optimal clinical decision-making and thus the possibility of better combating graft failure. 

Current renal function equations have been developed on native kidneys, which has been criticized, as kidney recipients have specific factors affecting their renal function, including immunosuppressive treatments and transplant-related comorbidities.

The research team sought a new renal function equation that could significantly improve the monitoring and management of kidney transplant patients.

More than 15,000 patients were included in the world’s largest cohort of transplant patients, for a total of 50,000 renal function measurements.

The new equation takes into account recipients’ age, gender and creatinine. Researchers have shown that this new equation outperforms current equations, across centers, countries and subpopulations of kidney recipients.

« Kidney recipients do not share the same characteristics as non-transplanted patients with chronic kidney disease, » explains Alexandre Loupy, of the Adult Nephrology-Renal Transplant Department at the Hôpital Necker – Enfants malades AP-HP, and director of an Inserm, Université Paris Cité research team. « Current renal function equations, developed in native kidneys, are therefore not fully adapted to kidney recipients, preventing optimal post-transplant follow-up. »

« We wanted to have a mathematical approach to developing the best kidney function equation for kidney transplant recipients, » explains Marc Raynaud, scientific director of an Inserm research team. « We then validated this new equation extensively in numerous transplant centers in France, Italy, Denmark, Croatia, the Netherlands, Australia, the USA and elsewhere. We made sure that this equation could be applied to any kidney transplant recipient in the world. »

This new kidney function equation could improve clinical decision-making for kidney transplant patients. The research team is therefore currently working with medical agencies to promote this equation.

While the Food and Drug Administration and the European Medicines Agency are currently considering decline in renal function as an endpoint predicting transplant failure, this new equation could be used in clinical trials as an endpoint to accelerate research and the potential identification of new treatments.

Reference : Marc Raynaud, Solaf Al-Awadhi, Ivana Juric, Gillian Divard, Yannis Lombardi, Nikolina Basic-Jukic, Olivier Aubert, Laurence Dubourg, Ingrid Masson, Christophe Mariat, Dominique Prié, Vincent Pernin, Moglie Le Quintrec, Timothy S Larson, Mark D Stegall, Boris Bikbov, Piero Ruggenenti, Laurent Mesnard,  Hassan N Ibrahim,  Marie Bodilsen Nielsen,  Arthur J Matas,  Brian J Nankivell,,  Stan Benjamens, Robert A Pol, associate professor of transplant surgery16,  Stephan J L Bakker,  Xavier Jouven,  Christophe Legendre,  Nassim Kamar,  Byron H Smith,  Hani M Wadei,  Antoine Durrbach,  Flavio Vincenti,  Giuseppe Remuzzi,  Carmen Lefaucheur,  Andrew J Bentall,  Alexandre Loupy. BMJ.