Why scale alone is not enough: innovation dynamics in single-centre vs. multicentre kidney paired donation

PURPOSE OF REVIEW: Kidney paired donation (KPD) has become an established strategy for overcoming immunological barriers to kidney transplantation. Although regional, national, and international registries have expanded donor pools and transplant opportunities, successful KPD depends on more than scale alone. This review examines the evolution of KPD delivery models and the complementary roles of multicentre and mature single-centre programs. RECENT FINDINGS: Multicentre KPD programs have facilitated increasingly complex exchanges through larger donor pools, advanced matching algorithms, and international collaboration. However, challenges remain, including logistical complexity, financial barriers, inter-centre variability in immunological assessment, and reduced access for highly sensitized and blood group O recipients. Emerging evidence from experienced single-centre programs demonstrates that standardized human leukocyte antigen (HLA) assessment, integrated multidisciplinary decision-making, and innovative matching strategies - including compatible pair participation, selective HLA- and ABO-incompatible transplantation, and complex exchange chains - can safely expand transplant opportunities while maintaining excellent outcomes. SUMMARY: Multicentre registries are essential for maximizing donor pool size and equitable access to transplantation. However, mature single-centre programs provide an integrated environment that promotes innovation, standardized immunological assessment, and rapid implementation of novel matching strategies. Future KPD systems should combine the scale of national registries with the expertise, flexibility, and innovation of experienced single-centre programs.