Impact of recurrent IgA nephropathy on long-term kidney transplant outcomes: a cohort comparison with autosomal dominant polycystic kidney disease

Background IgA nephropathy (IgAN) can recur following kidney transplantation and may compromise long-term graft survival. Autosomal dominant polycystic kidney disease (ADPKD) represents a non-recurrent comparator with excellent transplant outcomes. However, direct long-term comparisons between these diseases, particularly accounting for IgAN recurrence, remain limited. Methods We retrospectively analysed kidney transplant recipients transplanted between 2010 and 2023 for IgAN ( n = 137) or ADPKD ( n = 122) as primary cause of end stage kidney disease at a large UK transplant centre. IgAN recipients were stratified by biopsy-confirmed recurrence. The primary outcome was death-censored graft survival (DCGS). Secondary outcomes included patient survival, causes of graft failure, and post-transplant renal function. Survival was assessed with Kaplan–Meier methods and Cox regression analyses. Results Over a median follow-up of 6.38 years (IgAN) and 7.04 years (ADPKD), overall DCGS and recipient survival were comparable between the IgAN and ADPKD cohorts. However, recurrence identified a distinct high-risk subgroup within IgAN. Recurrence was observed in 12.4% of recipients and was associated with markedly inferior graft survival: 10-year DCGS was 35.8% in recurrent IgAN versus 88.8% in non-recurrent IgAN ( p < 0.05). In univariate Cox regression, recurrence was associated with graft failure (HR 5.50, 95% CI 2.33–12.96). Patient survival did not differ by primary disease or recurrence status. Conclusion Although overall long-term outcomes following transplantation are similar in IgAN and ADPKD, recurrence delineates a subgroup of IgAN recipients with substantially inferior graft survival. These findings highlight recurrent IgAN as a major driver of late allograft failure and underscore the need for sustained surveillance and strategies to mitigate recurrent disease.