Pediatric lung transplantation in Japan across legislative and allocation reforms: A nationwide registry analysis of waitlist and post-transplant outcomes

BACKGROUND: Pediatric lung transplantation is a life-saving option for end-stage lung disease, but national data from Japan, particularly regarding the impact of recent policy changes, are limited. METHODS: Nationwide registries of candidates (deceased-donor waitlist) and recipients in Japan (1998-2024) were analyzed with follow-up through July 2025. Outcomes were evaluated across three eras defined by the 2010 legislative revision and the 2020 pediatric priority rules. Waitlist outcomes were assessed within 2 years of listing and post-transplant survival within 2 years of transplantation (administrative censoring at 730 days) to support fair era comparisons. RESULTS: Among 2732 candidates, 149 (5.5%) were children. Within 2 years of listing, pediatric candidates were more likely to undergo lung transplantation than adults (35.6% vs 18.2%) and less likely to die on the waitlist (13.4% vs 29.7%). The proportion transplanted within 2 years increased from 9.4% in 1998-2009 to 38.2% in 2010-2019 and 49.0% in 2020-2024, while 2-year waitlist death decreased from 21.9% to 13.2% and 8.2%. At 2 years after transplantation, survival was 86.0% in pediatric recipients and 81.8% in adults; pediatric recipient status remained independently associated with lower mortality (aHR 0.47, 95% CI 0.32-0.71; p < 0.001). Descriptive Kaplan-Meier curves up to 10 years suggested favorable longer-term survival, with broadly comparable outcomes after pediatric living-donor and deceased-donor transplantation. CONCLUSIONS: Pediatric lung transplantation in Japan remains numerically limited but has substantially benefited from legislative and allocation reforms, with improved access to transplantation and reduced waitlist mortality. These findings provide a current national reference for pediatric lung transplantation in a donor-limited setting.