#153 The risk of post-transplant recurrent immunoglobulin A nephropathy: the association with post-transplant steroid use
Authors: Thrane Øhrstrøm Mette , Schultz Michael Dyrehauge , Bistrup Claus , Birn Henrik 
Published: May 2024

Abstract

Background and Aims
Immunoglobulin A nephropathy (IgAN) is the most common cause of kidney failure among glomerulopathies worldwide and it is reported that approximately 6-7% of all kidney transplantation is due to IgAN. It is well known that IgAN can recur in the kidney allograft and previous studies suggest that recurrent IgAN is the third most common cause of graft loss in patients with IgAN as primary disease. There is currently no effective treatment for recurrent IgAN, and the main goal is therefore to prevent recurrence in the allograft.
Post-transplant steroid therapy is a cornerstone in many immunosuppressive regimens, but steroid treatment also come with several side effects leading to the use of steroid-free protocols.
Controversy remains as to whether the use of steroid affects the risk of recurrent IgAN. Previous, retrospective studies report widely divergent associations between the use of steroids and the risk of recurrent IgAN and thus, more research on the association between steroid use and the risk of recurrent IgAN is warranted.
We examined this by taking advantage of the fact that two different standard immunosuppression protocols have been employed at two Danish transplantation centers, of which one included steroids and the other did not. The patients treated at the two transplantations centers were otherwise similar with respect to ethnicity, socio-economic status and other aspects of treatment differing only by regional residency. This provided a unique opportunity to compare the association between steroid use, recurrence rate and graft survival. We furthermore aimed to identify potential risk factors for recurrent IgAN.

Method
A retrospective cohort study including all adult patients (age ≥ 18 years) with biopsy-proven IgAN and a first-time kidney-only transplantation from 1990 to 2020 at either Aarhus University Hospital or Odense University Hospital using a steroid containing or a steroid free post-transplant immunosuppressive protocol, respectively. Renal transplant patients with IgAN were identified from the Danish Nephrology Registry and data on medical treatment, graft survival and histopathological evidence of recurrent IgAN were extracted from electronic medical journals. Data is presented by Aalen-Johansen and Kaplan-Meier plot, and associations between risk factors for recurrent IgAN were analyzed by cox-regression.

Results
A total of 120 first-time kidney recipients were included in the study. Biopsy-proven, recurrent IgAN was identified in 17 (14.2%) recipients. The median time from transplantation to recurrence was 2.91 years (IQR 0.89−5.60). Only one of 18 (15%) recipients adhering to steroid-free protocol was diagnosed with recurrent IgAN during the study period. The accumulated use of steroid as part of the immunosuppression regime was not associated with the risk of recurrent IgAN (unadjusted HR (95% CI) =1.02 (0.94−1.12)). Transplantation with genetically related living donor was associated with a greater risk of recurrent IgAN compared with non-genetically related ((unadjusted HR (95% CI) = 3.90 (1.37−11.10)) and recipients with recurrent IgAN were more likely to be younger at time of been diagnosed with IgAN and had a shorter time from being diagnosed to kidney failure when compared to recipients with non-recurrent IgAN. There were no associations between the risk of recurrent IgAN and induction therapy or HLA-mismatches. The 10-year death censored graft survival was 45% for recipients with recurrent IgAN, compared to 80% for recipients with non-recurrent IgAN.

Conclusion
The risk of recurrent IgAN after kidney transplantation was not associated with the use of steroids as part of the immunosuppression protocol, whereas recipients receiving a kidney from a genetic related donor appeared to have a higher risk of recurrent IgAN.