Long-Term Outcome of Kidney Retransplantation in Comparison With First Transplantation: A Propensity Score Matching Analysis

Early steroid withdrawal and kidney transplant outcomes in first-transplant and retransplant recipients

BACKGROUND

Early steroid withdrawal (ESW) is often preferred over conventional steroid maintenance (CSM) therapy for kidney transplant recipients with low immunological risks because it may minimize immunosuppression-related adverse events while achieving similar transplant outcomes. However, the risk-benefit balance of ESW could be less favorable in retransplant recipients given their unique immunological risk profile. We hypothesized that the association of ESW with transplant outcomes would differ between first-transplant and retransplant recipients.

METHODS

To assess whether the impact of ESW differs between first and retransplant recipients, we studied 210 086 adult deceased-donor kidney transplant recipients using the Scientific Registry of Transplant Recipients. Recipients who discontinued maintenance steroids before discharge from transplant admission were classified with ESW; all others were classified with CSM. We quantified the association of ESW (vs CSM) with acute rejection, death-censored graft failure and death, addressing retransplant as an effect modifier, using logistic/Cox regression with inverse probability weights to control for confounders.

RESULTS

In our cohort, 26 248 (12%) were retransplant recipients. ESW was used in 30% of first-transplant and 20% of retransplant recipients. Among first-transplant recipients, ESW was associated with no significant difference in acute rejection {adjusted odds ratio (aOR) = 1.04 [95% confidence interval (CI) = 1.00-1.09]}, slightly higher hazard of graft failure [hazard ratio (HR) = 1.09 (95% CI = 1.05-1.12)] and slightly lower mortality [HR = 0.93 (95% CI = 0.91-0.95)] compared with CSM. Nonetheless, among retransplant recipients, ESW was associated with notably higher risk of acute rejection [OR = 1.42 (95% CI = 1.29-1.57); interaction P < .001] and graft failure [HR = 1.24 (95% CI = 1.14-1.34); interaction P = .003], and similar mortality [HR = 1.01 (95% CI = 0.94-1.08); interaction P = .04].

CONCLUSIONS

In retransplant recipients, the negative impacts of ESW on transplant outcomes appear to be non-negligible. A more conservatively tailored approach to ESW might be necessary for retransplant recipients.

Transplantation and immigration: Comparing infectious complications and outcomes between foreign-born and US-born kidney transplant recipients in Minnesota

BACKGROUND

Foreign-born kidney transplant recipients (FBKTRs) are at increased risk for reactivation of latent infections that may impact outcomes. We aimed to compare the etiology of infections and outcomes between FBKTR and United States KTRs (USKTR).

METHODS

We performed a retrospective study of patients who underwent kidney transplantation between January 1, 2014 and December 31, 2018 at two transplant centers in Minnesota. Frequency and etiology of infections as well as outcomes (graft function, rejection, and patient survival) at 1-year post-transplant between FBKTR and USKTR were compared.

RESULTS

Of the 573 transplant recipients, 124 (21.6%) were foreign-born and 449 (78.4%) US-born. At least one infection occurred in 411 (71.7%) patients (38.2% bacterial, 55% viral, 9.4% fungal). Viral infections were more frequent in FBKTR, particularly BK viremia (38.7% vs. 21.2%, p < .001). No statistical differences were found for bacterial or fungal infections; no parasitic infections were identified in either group. No geographically-restricted infections were noted aside from a single case of Madura foot in a FBKTR. Rejection episodes were more common in USKTR (p = .037), but stable/improving graft function (p = .976) and mortality (p = .451) at 1-year posttransplantation were similar in both groups. After adjusting for covariates, previous transplantation was associated with a higher number of infections (IRR 1.35, 95% confidence intervals 1.05-1.73, p = .020).

CONCLUSION

Although viral infections were more frequent in FBKTR, overall frequency and etiology of most infections and outcomes were similar between FBKTR and USKTR suggesting that comprehensive transplant care is providing timely prevention, diagnosis, and treatment of latent infections in FBKTR.

Use of Machine Learning Consensus Clustering to Identify Distinct Subtypes of Black Kidney Transplant Recipients and Associated Outcomes

Importance

Among kidney transplant recipients, Black patients continue to have worse graft function and reduced patient and graft survival. Better understanding of different phenotypes and subgroups of Black kidney transplant recipients may help the transplant community to identify individualized strategies to improve outcomes among these vulnerable groups.

Objective

To cluster Black kidney transplant recipients in the US using an unsupervised machine learning approach.

Design, Setting, and Participants

This cohort study performed consensus cluster analysis based on recipient-, donor-, and transplant-related characteristics in Black kidney transplant recipients in the US from January 1, 2015, to December 31, 2019, in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Each cluster's key characteristics were identified using the standardized mean difference, and subsequently the posttransplant outcomes were compared among the clusters. Data were analyzed from June 9 to July 17, 2021.

Exposure

Machine learning consensus clustering approach.

Main Outcomes and Measures

Death-censored graft failure, patient death within 3 years after kidney transplant, and allograft rejection within 1 year after kidney transplant.

Results

Consensus cluster analysis was performed for 22 687 Black kidney transplant recipients (mean [SD] age, 51.4 [12.6] years; 13 635 men [60%]), and 4 distinct clusters that best represented their clinical characteristics were identified. Cluster 1 was characterized by highly sensitized recipients of deceased donor kidney retransplants; cluster 2, by recipients of living donor kidney transplants with no or short prior dialysis; cluster 3, by young recipients with hypertension and without diabetes who received young deceased donor transplants with low kidney donor profile index scores; and cluster 4, by older recipients with diabetes who received kidneys from older donors with high kidney donor profile index scores and extended criteria donors. Cluster 2 had the most favorable outcomes in terms of death-censored graft failure, patient death, and allograft rejection. Compared with cluster 2, all other clusters had a higher risk of death-censored graft failure and death. Higher risk for rejection was found in clusters 1 and 3, but not cluster 4.

Conclusions and Relevance

In this cohort study using an unsupervised machine learning approach, the identification of clinically distinct clusters among Black kidney transplant recipients underscores the need for individualized care strategies to improve outcomes among vulnerable patient groups.

Donor lymphocyte infusions after first allogeneic hematopoietic stem-cell transplantation in adults with acute myeloid leukemia: a single-center landmark analysis

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is potentially curative for acute myeloid leukemia (AML). The inherent graft-versus-leukemia activity (GvL) may be optimized by donor lymphocyte infusions (DLI). Here we present our single-center experience of DLI use patterns and effectiveness, based on 342 consecutive adult patients receiving a first allo-HSCT for AML between 2009 and 2017. The median age at transplantation was 57 years (range 19-79), and the pre-transplant status was active disease in 58% and complete remission (CR) in 42% of cases. In a combined landmark analysis, patients in CR on day +30 and alive on day +100 were included. In this cohort (n=292), 93 patients received cryopreserved aliquots of peripheral blood-derived grafts for DLI (32%) and median survival was 55.7 months (2-year/5-year probability: 62%/49%). Median survival for patients receiving a first dose of DLI "preemptively," in the absence of relapse and guided by risk marker monitoring (preDLI; n=42), or only after hematological relapse (relDLI; n=51) was 40.9 months (2-year/5-year: 64%/43%) vs 10.4 months (2-year/5-year: 26%/10%), respectively. Survival was inferior when preDLI was initiated at a time of genetic risk marker detection vs mixed chimerism or clinical risk only. Time to first-dose preDLI vs time to first-dose relDLI was similar, suggesting that early warning and intrinsically lower dynamics of AML recurrence may contribute to effectiveness of preDLI-modified GvL activity. Future refinements of the preemptive DLI concept will benefit from collaborative efforts to diagnose measurable residual disease more reliably across the heterogeneous genomic spectrum of AML.

Risk Factors Influencing the Outcomes of Kidney Re-Transplantation

BACKGROUND Our kidney transplant waitlist includes 20% re-transplantations (TX2). Knowing what to expect is a clinical obligation. MATERIAL AND METHODS We compared graft and patient survival of all 162 TX2 patients, transplanted 2000 to 2009, with 162 patients after first transplantation (TX1) matched for age, sex, living/non-living donation, and transplantation date. Patient follow-up was 10 years. RESULTS TX2 graft and patient survivals were inferior to TX1 (p<0.001 and p=0.047). TX2 patients had a longer cumulative dialysis vintage, more human leucocyte antigen (HLA) mismatches, more panel-reactive HLA antibodies, more often received induction therapy with rabbit-antithymocyte globulin (rATG), and had a lower body mass index (all p<0.05). Death from infection and graft failure by rejection was more frequent after TX2 (both p<0.05) but not after TX1. Multivariable Cox regression analysis revealed that both cohorts had graft failure and death risk associated with infection and cardiovascular disease, and graft failure by humoral rejection. However, only TX2 patients had an additional risk of graft failure with early inferior graft function and of patient death with ≥2 comorbidities. Moreover, Kaplan-Meier analysis showed that TX2 and not TX1 patients had a lower graft and patient survival associated with infection and with ≥2 comorbidities (all p<0.05). CONCLUSIONS Re-transplantation is associated with worse graft outcomes mainly because of immunologic and graft-quality reasons, although the high number of comorbidities and infection severities aside from cardiovascular disease drive mortality. The more frequent rATG induction of TX2 patients could promote infection by enhancing immunosuppression. By addressing comorbidities, outcomes could possibly be improved.

Rapid re-transplantation safety following early kidney graft loss

INTRODUCTION

Early graft loss is a devastating kidney transplant complication associated with high mortality and an increased risk of sensitization to antigens from the failed graft. Moreover, if rapid re-transplantation were to occur, given that the human leukocyte antigen antibodies identification may not be reliable until several weeks after transplantation, the recipient's immunological status would be uncertain. Hence, there could be an increased immunological risk. To date, there is no information on whether a rapid re-transplantation after early graft loss, without a new reliable anti-HLA determination, is safe.

METHODS

We retrospectively analysed the number of rejections and the graft survival of re-transplanted patients with early graft loss (defined as graft failure before 30 days from transplant) from our centre between June 2003 and November 2019. The studied population was divided into rapid re-transplantation (performed within 30 days of early graft loss) and late re-transplantation (performed beyond those 30 days).

RESULTS

Forty-seven patients were re-transplanted after early graft loss. There were nine rapid re-transplantation cases with an 89% five-year graft survival and one antibody-mediated rejection episode. Furthermore, we identified 38 cases of late re-transplantation with a 69% five-year graft survival, 4 T cell-mediated, and 11 antibody-mediated rejections.

CONCLUSIONS

Rapid re-transplantation appears to be safe and does not entail increased rejection risk, nor does it impact long-term graft survival when compared to late re-transplantation.