Riad, Samy

Key Points Pediatric preemptive kidney transplantation rates in the United States vary by socioeconomic status (SES). The HOUsing-based index of SES, an individual-level SES measure derived from residential addresses, effectively predicts pediatric preemptive kidney transplant rates. Background Preemptive kidney transplantation in children is associated with better patient and graft survival compared with transplants after dialysis. However, preemptive kidney transplantation rates in children remain low. This study aimed to evaluate the effect of socioeconomic status (SES) on preemptive transplantation in children. Methods Our study included 173 Minnesota-resident pediatric kidney transplant recipients (younger than 18 years) transplanted at the University of Minnesota from 2010 to 2020. Using the HOUsing-based index of SES (HOUSES) index, a validated, individual SES measure based on housing units categorized into quartiles (Q1: lower SES; Q2–Q4: higher SES), we applied mixed-effects multivariable logistic models to examine the effects of HOUSES on preemptive kidney transplants and pretransplant dialysis duration. Results Of 173 pediatric kidney transplant recipients, 46 (26.6%) received a preemptive transplant, and of 109 recipients with dialysis duration data, 39 (35.8%) received dialysis for >1 year. After adjusting for age at kidney failure, sex, donor type, insurance type, and underlying cause of kidney failure, we observed significantly lower odds of preemptive transplantation among Q1 recipients compared with Q2–4 recipients (adjusted odds ratio, 0.31; 95% confidence interval, 0.11 to 0.90; P = 0.03). Conclusions Using the HOUSES index, we found significant socioeconomic disparities in preemptive kidney transplantation rates among children.

Background. The limitations of conventional measures of socioeconomic status (SES) limit our ability to elucidate the role of SES as a key element of social determinants of health in kidney transplantation. This study’s objective was to use an innovative SES measure, the HOUsing-based SES measure (HOUSES) index, to examine the effects of social determinants of health on access to and outcomes of kidney transplantation. Methods. Our study included residents of Minnesota (age older than 18 y) who underwent kidney transplantation at a single center between 2010 and 2020. SES was determined using the HOUSES index, categorized into quartiles (Q1 for lower, Q2–Q4 for higher SES). We used mixed-effects multivariable logistic and Cox models to examine the effects of HOUSES on preemptive transplants, pretransplant dialysis duration, and death-censored graft loss, adjusting for covariates. Results. Among 1975 eligible patients, 29.4% received preemptive transplants, 34.9% underwent pretransplant dialysis for >3 y, and 15.1% experienced death-censored graft loss for a median follow-up of 7.15 (interquartile range, 4.25–11.38) y. Lower SES recipients (Q1) demonstrated decreased preemptive transplant likelihood (adjusted odds ratio [aOR]: 0.74; 95% confidence interval [CI], 0.57-0.97; P = 0.03), longer dialysis duration (>3 y; aOR: 1.43; 95% CI, 1.01-2.03; P = 0.046), and higher death-censored graft loss (adjusted hazard ratio 1.36; 95% CI, 1.02-1.12; P = 0.036) versus higher SES recipients (Q2–Q4). Conclusions. We observed significant socioeconomic disparities in kidney transplant access, dialysis duration, and graft survival. The HOUSES index may be a promising tool for individual-based targeted interventions as it identifies SES on an individual rather than an area-level basis.

Background: Previous data suggested that the outcomes for liver-alone transplant recipients following transjugular intrahepatic portosystemic shunt (TIPS) insertion were comparable to those without TIPS. This study investigates the association between TIPS and outcomes among simultaneous liver–kidney (SLK) recipients in the United States. Methods: Utilizing the Scientific Registry for Transplant Recipients (SRTR) standard analysis file from 2003 to 2022, we examined 9717 adult SLK recipients, among whom 858 had undergone TIPS before transplantation. Kaplan–Meier curves were generated to assess recipient and death-censored liver and kidney graft survival. Mixed-effects Cox proportional hazard models were employed to analyze the association between TIPS and the outcomes of interest, where the transplant center was treated as a random effect. The models were adjusted for recipient age, sex, MELD score, diabetes, duration of listing, induction, steroid maintenance, hepatitis C status, donor age, donor sex, cold ischemia time, local vs. shipped organs, and allocation era. Results: Overall, the two groups were comparable, with minor differences. Notably, the median liver waiting time was significantly longer in the TIPS group compared to the non-TIPS group (4.1 vs. 2 months, p < 0.001). One-year rejection rates for liver and kidney allografts did not differ significantly between groups. Univariable Cox regression analyses demonstrated no association between TIPS and worse outcomes for recipient, liver, and kidney survival (p = 0.65, p = 0.22, and p = 0.54, respectively). TIPS did not emerge as a predictor of recipient or death-censored liver or kidney graft survival in multivariable models. Conclusion: In this extensive national cohort of SLK transplant recipients, pre-transplant TIPS was not linked to adverse outcomes for recipients or their allografts.

Background. The impact of induction type or high-risk viral discordance on older kidney transplant recipients is unclear. Herein, we analyzed the association between induction type, viral discordance, and outcomes for older recipients. Methods. We analyzed the Scientific Registry of Transplant Recipients standard analysis file for all primary kidney transplant recipients older than 55 y who were transplanted between 2005 and 2022. All transplants were crossmatch negative and ABO-compatible. Recipients were discharged on tacrolimus and mycophenolate ± steroids. Recipients were categorized into 3 groups by induction received: rabbit antithymocyte globulin (r-ATG; N = 51 079), interleukin-2 receptor antagonist (IL-2RA; N = 22 752), and alemtuzumab (N = 13 465). Kaplan-Meier curves were generated for recipient and graft survival, and follow-up was censored at 10 y. Mixed-effect Cox proportional hazard models examined the association between induction type, high-risk viral discordance, and outcomes of interest. Models were adjusted for pertinent recipient and donor characteristics. Results. Induction type did not predict recipient survival in the multivariable model, whereas Epstein-Barr virus high-risk discordance predicted 14% higher mortality (1.14 [1.07-1.21], P < 0.01). In the multivariable model for death-censored graft survival, alemtuzumab, but not IL-2RA, was associated with an increased risk of graft loss (1.18 [1.06-1.29], P < 0.01) compared with r-ATG. High-risk cytomegalovirus discordance predicted 10% lower death-censored graft survival (1.10 [1.01-1.19], P < 0.02). Live donor and preemptive transplantation were favorable predictors of survival. Conclusions. In this large cohort of older transplant recipients, alemtuzumab, but not IL-2RA, induction was associated with an increased risk of graft loss compared with r-ATG. Cytomegalovirus and Epstein-Barr virus high-risk viral discordance portended poor graft and recipient survival, respectively.