A meta-analysis of graft survival, patient survival and delayed graft function in first-time and repeat kidney transplants

Abstract

Background: Previous evidence showed that while first-time kidney transplants (KT) typically yield better outcomes, repeat and subsequent transplants were associated with increased risks of graft failure and adverse patient outcomes, yet conflicting findings exist. The aim of this meta-analysis is to compare graft survival and delayed graft function (DGF) outcomes in first-time KT, repeat KT (regrafts) and subsequent KT.

Methods: Relevant studies were identified through comprehensive searches in PubMed, Web of Science, Cochrane Library, MEDLINE (Ovid) and Scopus until 8 October 2024. Primary outcomes include graft survival and DGF, compared with repeat and subsequent KT.

Results: The meta-analysis included a total of 16 studies. Analysis on long-term graft survival revealed that patients who underwent a first KT had significantly better graft survival compared with those who received a second transplant [86.7% versus 77.6%; odds ratio (OR) 1.40, 95% confidence interval (CI) 1.14-1.71, P = .001]. At 5 years post-transplant, first KT recipients continued to demonstrate superior graft survival (OR 1.41, 95% CI 1.13-1.77, P = .003), although this difference diminished by 10 years, with no significant disparity observed (OR 1.26, 95% CI 0.88-1.81, P = .20). Graft survival at 5 years was also significantly higher in second KT recipients compared with those undergoing a third transplant (OR 2.66, 95% CI 1.86-3.80, P < .00001). Patient survival outcomes were largely comparable between first and second KT groups, with no statistically significant differences in overall survival (OR 1.25, 95% CI 0.87-1.81, P = .23). At specific time points, the 5-year survival rate showed a borderline non-significant trend favoring first KT recipients (OR 1.63, 95% CI 0.97-2.73, P = .06), while the 10-year survival rate showed no difference (OR 0.94, 95% CI 0.67-1.32, P = .71). Survival rates between second and subsequent retransplants (e.g. third or fourth KT) showed no significant variation, including at 5 years (P = .37 and P = .90, respectively). DGF rates did not differ significantly between first and second KT recipients (P = .11).

Conclusion: These findings underscore the superior graft survival associated with first and second KT compared with subsequent retransplants, particularly in the early post-transplant period, while highlighting the lack of significant differences in overall patient survival across groups; however, variability in outcomes due to study heterogeneity and patient-specific factors warrants cautious interpretation and tailored clinical approaches.

Keywords: first-time transplants; graft survival; kidney transplantation; patient survival; repeat transplants.