Managing the Failing Allograft

Factors Associated With Long-term Kidney Allograft Survival: A Contemporary Analysis of the UNOS Database

BACKGROUND

Various clinicopathologic markers, such as 1-year serum creatinine (Cr), have been used to prognosticate kidney allografts after transplantation. However, a contemporary analysis of their relationship with long-term graft survival is lacking. This study aimed to analyze recent data on the association of prognostic factors with kidney allograft survival in patients who underwent transplantation in the modern era.

METHODS

Adult kidney-transplant recipients in the UNOS database (2008-2020) were identified. Living and deceased donor allografts were analyzed separately and stratified by 1-year serum Cr level: ≤1.0, 1.0 to 1.5, 1.5 to 2.0, and >2.0 mg/dL. Time-to-event analysis was performed with long-term death-censored graft survival as the primary outcome. In addition, factors associated with raised 1-year serum Cr and with long-term allograft failure were identified.

RESULTS

174,547 patients were included. Ten-year survival decreased with increasing 1-year creatinine, and these trends persisted on adjusted analysis for both living donor (Cr ≤ 1.0 mg/dL: reference; Cr 1.0-1.5 mg/dL aHR = 1.77 [1.59-1.96]; Cr 1.5-2.0 mg/dL aHR = 3.24 [2.89-3.64] and; Cr > 2.0 mg/dL aHR = 9.78, [8.64-11.07], P < .01) as well as deceased donor allografts (Cr ≤ 1.0 mg/dL: reference; Cr 1.0-1.5 mg/dL aHR = 1.74 [1.63-1.86]; Cr 1.5-2.0 mg/dL aHR = 3.06 [2.84-3.30] and; Cr > 2.0 mg/dL aHR = 8.51, [7.89-9.18], P < .01).

CONCLUSION

These results characterize the association between 1-year serum creatinine levels and other clinicopathologic factors with long-term kidney allograft survival. We demonstrate the ability of prognostic factors to stratify patients by risk of graft failure in a contemporary patient cohort that is representative of current practice and outcomes.

The failing kidney allograft: A review and recommendations for the care and management of a complex group of patients

The return to dialysis after allograft failure is associated with increased morbidity and mortality. This transition is made more complex by the rising numbers of patients who seek repeat transplantation and therefore may have indications for remaining on low levels of immunosuppression, despite the potential increased morbidity. Management strategies vary across providers, driven by limited data on how to transition off immunosuppression as the allograft fails and a paucity of randomized controlled trials to support one approach over another. In this review, we summarize the current data available for management and care of the failing allograft. Additionally, we discuss a suggested plan for immunosuppression weaning based upon the availability of re-transplantation and residual allograft function. We propose a shared-care model in which there is improved coordination between transplant providers and general nephrologists so that immunosuppression management and preparation for renal replacement therapy and/or repeat transplantation can be conducted with the goal of improved outcomes and decreased morbidity in this vulnerable patient group.

Management of Immunosuppression After Kidney Transplant Failure: Effect on Patient Sensitization

BACKGROUND

Immunosuppressive treatment is often interrupted in the first months following kidney transplant failure (KTF) to limit side effects. The aim of this study was to assess the effect of prolonged treatment (PT) of more than 3 months' duration after KTF on HLA sensitization and treatment tolerance.

METHODS

We performed a retrospective observational study involving 119 patients with KTF in 3 French kidney transplant centers between June 2007 and June 2017. Sensitization was defined as the development of HLA donor-specific antibodies (DSA).

RESULTS

In the PT group receiving calcineurin inhibitor (CNI) treatment, 30 of 52 patients (57.7%) were sensitized vs 52 of 67 patients (77.6%) who had early cessation of treatment (P = .02). The results were confirmed by multivariate analysis (odds ratio [OR] = 0.39, 95% confidence interval [CI] [0.16; 0.98], P = .04). The development of de novo DSAs after CNI treatment (n = 63/90 [70.0%]) was significantly more frequent than during CNI treatment, (n = 18/52 [34.6%], P = .01). Panel-reactive antibody ≥85% was lower in the PT group in multivariate analysis (OR = 0.28, 95% CI [0.10; 0.78], P = .02). No differences in the rates of infection, cardiovascular complications, neoplasia, and deaths were observed between the 2 groups. In multivariate analysis, continuation of corticosteroid treatment had no influence on sensitization but was associated with a higher rate of infection (OR = 2.66, 95% CI [1.09; 6.46], P = .03).

CONCLUSION

Maintenance of CNI treatment after return to dialysis in patients requesting a repeat transplant could avoid the development of anti-HLA sensitization with a good tolerance.

Transplant Patients With Failing Renal Allografts

Progress in patient care and immunosuppressive medications has resulted in improved allograft survival in the early posttransplant period; however, substantial graft loss continues in the long term. Therefore, the number of dialysis patients with failed allografts is increasing progressively. These patients have a worse prognosis than naive dialysis patients. Cardiovascular causes are the leading cause of death, followed by infections and malignancies. Delay in return to dialysis, a chronic inflammatory state, infections, and cancer are contributing factors to mortality, whereas type of dialysis modality does not have a significant effect on outcomes. Graft nephrectomy is a risky operation; therefore, it should not be a routine procedure and rather should be performed only when indicated. Overall, most grafts are left in place, whereas graft nephrectomy is performed in atients with graft intolerance syndrome. Management of immunosuppressive drugs after graft failure is controversial. In the case of maintaining immunosuppression, there is increased risk of infections, cardiovascular diseases, and malignancies and also steroid-related adverse effects. On the other hand, discontinuation of immunosuppressants may result in loss of residual allograft function and also acute graft inflammation. Together, immunosuppressive drugs are almost always discontinued in these patients because of their inherent adverse effects. Considering the sequence of cessation, first antiproliferative drugs are stopped, followed by calcineurin inhibitors, and finally steroids. Because many studies show a clear survival benefit, every attempt should be made for a retransplant in patients with failed renal allografts.

Effects of DNA Methylation on Progression to Interstitial Fibrosis and Tubular Atrophy in Renal Allograft Biopsies: A Multi-Omics Approach

Progressive fibrosis of the interstitium is the dominant final pathway in renal destruction in native and transplanted kidneys. Over time, the continuum of molecular events following immunological and nonimmunological insults lead to interstitial fibrosis and tubular atrophy and culminate in kidney failure. We hypothesize that these insults trigger changes in DNA methylation (DNAm) patterns, which in turn could exacerbate injury and slow down the regeneration processes, leading to fibrosis development and graft dysfunction. Herein, we analyzed biopsy samples from kidney allografts collected 24 months posttransplantation and used an integrative multi-omics approach to understand the underlying molecular mechanisms. The role of DNAm and microRNAs on the graft gene expression was evaluated. Enrichment analyses of differentially methylated CpG sites were performed using GenomeRunner. CpGs were strongly enriched in regions that were variably methylated among tissues, implying high tissue specificity in their regulatory impact. Corresponding to this methylation pattern, gene expression data were related to immune response (activated state) and nephrogenesis (inhibited state). Preimplantation biopsies showed similar DNAm patterns to normal allograft biopsies at 2 years posttransplantation. Our findings demonstrate for the first time a relationship among epigenetic modifications and development of interstitial fibrosis, graft function, and inter-individual variation on long-term outcomes.

Prolonged immunosuppression preserves nonsensitization status after kidney transplant failure

BACKGROUND

When kidney transplants fail, transplant medications are discontinued to reduce immunosuppression-related risks. However, retransplant candidates are at risk for allosensitization which prolonging immunosuppression may minimize. We hypothesized that for these patients, a prolonged immunosuppression withdrawal after graft failure preserves nonsensitization status (PRA 0%) better than early immunosuppression withdrawal.

METHODS

We retrospectively examined subjects transplanted at a single center between July 1, 1999 and December 1, 2009 with a non-death-related graft loss. Subjects were stratified by timing of immunosuppression withdrawal after graft loss: early (≤3 months) or prolonged (>3 months). Retransplant candidates were eligible for the main study where the primary outcome was nonsensitization at retransplant evaluation. Non-retransplant candidates were included in the safety analysis only.

RESULTS

We found 102 subjects with non-death-related graft loss of which 49 were eligible for the main study. Nonsensitization rates at retransplant evaluation were 30% and 66% for the early and prolonged immunosuppression withdrawal groups, respectively (P=0.01). After adjusting for cofactors such as blood transfusion and allograft nephrectomy, prolonged immunosuppression withdrawal remained significantly associated with nonsensitization (adjusted odds ratio=5.78, 95% CI [1.37-24.44]). No adverse safety signals were seen in the prolonged immunosuppression withdrawal group compared to the early immunosuppression withdrawal group.

CONCLUSIONS

These results suggest that prolonged immunosuppression may be a safe strategy to minimize sensitization in retransplant candidates and provide the basis for larger or prospective studies for further verification.