Living donation and pre-emptive transplantation are more important than HLA matching in pediatric kidney transplantation: Results from a 33-year comparative OPTN study
Alicia Paessler1, Ioannis Kostakis2, Ioannis Loukopoulos1,3, Zainab Arslan1,4, Nicos Kessaris1,3, Jelena Stojanovic1,4.
1Renal Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom; 2Transplant Surgery, Royal Free NHS Foundation Trust, London, United Kingdom; 3Transplant Surgery, Guys and St Thomas' NHS Foundation Trust, London, United Kingdom; 4Institute of Child Health, UCL, London, United Kingdom
Introduction: Donor kidney allografts are matched to recipients considering various factors including similarities in Human Leucocyte Antigens (HLA) expressed by the donor and prospective recipients. Poorly HLA matched transplants have poorer long-term outcomes, however it is unclear whether living donation or pre-emptive transplantation can counteract the effects of HLA mismatches. We reviewed the outcomes for all paediatric kidney transplants in the USA over a 33-year period by different HLA matches, and aimed to identify other factors which may contribute more significantly to long-term outcomes.
Methods: Data were retrieved on all kidney transplants performed in paediatric recipients in 1987-2020, from the United Network for Organ Sharing. These were analysed by number of HLA mismatches and compared between pre-emptive and non-pre-emptive transplants and by donor type. Data were compared using chi-square test, ANOVA and Kaplan-Meier survival analysis.
Results: 21,500 patients were included for analysis. Patients with unfavourable HLA matches had higher rates of delayed graft function (10.0% vs 6.6%, p<0.01) and lower graft survival (53% vs 62% at 10 years, p<0.01). Patients with unfavourable HLA matched transplants from living donors had better graft survival than patients with favourable HLA matched transplants from deceased donors (56% at 10 years vs 51%, p<0.01). Patients with pre-emptive unfavourable HLA matched transplants had better graft and patient survival than patients with non-pre-emptive favourable HLA matched transplants (61% at 10 years vs 59%, p=0.02 and 96% vs 91%, p<0.01 respectively).
Discussion: Children who receive kidney transplants with a higher number of HLA mismatches have worse clinical outcomes. However, living donation and pre-emptive transplantation have a more significant impact on clinical outcomes and lead to better graft and patient survival regardless of HLA matching. Patients with eligible living donors may consider proceeding with living donation despite an unfavourable HLA match.
[1] HLA
[2] Kidney Transplant
[3] OPTN