Influence of race on kidney transplantation in the Department of Defense healthcare system

Factors associated with graft survival in South African adolescent renal transplant patients at CMJAH over a 20-year period (GRAFT-SAT Study)

BACKGROUND

In the developed world, studies on transition of adolescent renal transplant patients have noted high rates of rejection, non-adherence and graft loss. There is a paucity of data in developing countries and none from South Africa.

METHODS

We evaluated patient and graft outcomes during adolescence (10-19 years), of patients who received a renal transplant over a 20-year period (1990-2010), at a tertiary hospital in Johannesburg. Cox proportional hazards models and Kaplan-Meier curves were used to analyse graft and patient survival.

RESULTS

A total of 213 kidney transplants were done in 162 patients during the study period, 165 transplants occurred during the adolescent period. Factors associated with graft failure on multivariate analysis included non-white race, transplant during the adolescent period ([aHR] 3.94; 95% [CI], 2.25-6.91), non-compliance with follow-up (aHR 3.89; 95% CI, 1.76-8.60) and receipt of a DD graft (aHR 2.10; 95% CI, 1.27-3.48). Patient survival rates at 1-, 3-, 5- and 10-years were 98.8%, 97.6%, 95.1% and 93.9% respectively.

CONCLUSION

High rates of graft rejection and loss occurred in South African renal transplant recipients in the adolescent period, especially in those retained in paediatric care. Establishment of transition clinics may improve the graft outcomes of this vulnerable group and warrant further research.

African American polycystic kidney patients receive higher risk kidneys, but do not face increased risk for graft failure or post-transplant mortality

African Americans (AA) are disproportionately affected by end-stage renal disease (ESRD) and have worse outcomes following renal transplantation. Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic condition leading to ESRD necessitating transplant. We explored this population with respect to race by conducting a retrospective analysis of the UNOS database between 2005 and 2019. Our study included 10,842 (AA n = 1661; non-AA n = 9181) transplant recipients whose primary diagnosis was ADPKD. We further stratified the AA ADPKD population with respect to blood groups (AA blood type B n = 295 vs AA non-B blood type n = 1366), and also compared this cohort to AAs with a diagnosis of DM (n = 16,706) to identify unique trends in the ADPKD population. We analyzed recipient and donor characteristics, generated survival curves, and conducted multivariate analyses. African American ADPKD patients waited longer for transplants (924 days vs 747 days P < .001), and were more likely to be on dialysis (76% vs 62%; p < .001). This same group was also more likely to have AA donors (21% vs 9%; p < .001) and marginally higher KDPI kidneys (0.48 vs 0.45; p < .001). AA race was a risk factor for delayed graft function (DGF), increasing the chance of DGF by 45% (OR 1.45 95% CI 1.26-1.67; p < .001). AA race was not associated with graft failure (HR 1.10 95% CI 0.95-1.28; p = .21) or patient mortality (HR 0.84 95% CI 0.69-1.03; p = .09). Racial disparities exist in the ADPKD population. They should be continually studied and addressed to improve transplant equity.

Simultaneous Pancreas and Kidney Transplantation is Associated With Inferior Long-Term Outcomes in African Americans

OBJECTIVES

Simultaneous pancreas and kidney transplant (SPK) is the most effective treatment for patients with type 1 diabetes mellitus and renal failure. However, the effect of ethnicity on SPK outcomes is not well understood.

METHODS

We studied the influence of recipient ethnicity on SPK using the United Network for Organ Sharing database. A retrospective review of 20,196 SPK patients from 1989 to 2014 was performed. The recipients were divided into 4 groups: 15,833 whites (78.40%), 2708 African Americans (AA) (14.39%), 1456 Hispanics (7.21%), and 199 Asians (0.99%).

RESULTS

Hispanics and Asians experienced the best overall graft and patient outcomes. Both groups demonstrated significantly superior graft and patient survival rates compared with whites at 1, 3, 5, 10, and 15 years (all P < 0.0001). African Americans experienced significantly superior 1- and 3-year patient survival compared with whites (both P < 0.0001). African Americans also experienced significantly superior 1-year kidney and pancreas graft survival compared with whites (P < 0.0001). However, AA experienced significantly inferior patient and allograft outcomes for all other time points compared with whites.

CONCLUSIONS

Based on United Network for Organ Sharing data from 1989 to 2014, AA have worse long-term patient and graft survival rates compared with whites, Hispanics, and Asians undergoing SPK.

Cytolytic Induction Therapy Improves Clinical Outcomes in African-American Kidney Transplant Recipients

OBJECTIVE

Determine the impact of cytolytic versus IL-2 receptor antibody (IL-2RA) induction on acute rejection, graft loss and death in African-American (AA) kidney transplant (KTX) recipients.

BACKGROUND

AAs are underrepresented in clinical trials in transplantation; thus, there is controversy regarding the optimal choice of perioperative antibody induction in KTX to improve outcomes.

METHODS

National cohort study using US transplant registry data from January 1, 2000 to December 31, 2009 in adult solitary AA KTX recipients, with at least 5 years of follow-up. Multivariable logistic and Cox regression were utilized to assess the outcomes of acute rejection, graft loss, and mortality, with interaction terms to assess effect modification.

RESULTS

Twenty-five thousand eighty-four adult AAs receiving solitary KTX were included, 16,927 (67.5%) received cytolytic induction and 8157 (32.5%) received IL-2RA induction. After adjustment for recipient sociodemographics, donor, and transplant characteristics, the use of cytolytic induction therapy reduced the risk of acute rejection by 32% (OR 0.68, 0.62-0.75), graft loss by 9% (HR 0.91, 0.86-0.97), and death by 12% (HR 0.88, 0.83-0.94). There were a number of significant effect modifiers, including public insurance, panel reactive antibody, delayed graft function, and steroid withdrawal; in these groups, cytolytic induction substantially improved clinical outcomes.

CONCLUSIONS

These data demonstrate that cytolytic induction therapy, as compared with IL-2RA, reduces the risk of rejection, graft loss, and death in adult AA KTX recipients, particularly in those who are sensitized, receive public insurance, develop delayed graft function, or undergo steroid withdrawal.

Understanding the influence of ethnicity and socioeconomic factors on graft and patient survival after kidney transplantation

BACKGROUND

Studies on the influence of socioeconomic factors and ethnicity on the results of kidney transplantation have led to various outcomes. In this study, we analyzed the influence of a combination of these factors on graft and patient survival in a population of kidney transplant recipients.

METHODS

This retrospective study included all 1,338 patients who received a kidney transplant between 2000 and 2011 (825 living, 513 deceased donor transplantations). Both clinical and socioeconomic variables were studied. Clinical variables were recipient age, gender, ethnicity, original disease, maximum and current panel reactive antibodies, ABO blood type, retransplants, pretreatment, time on dialysis, comorbidity, transplant year, total number of HLA mismatches, donor type (living or deceased), age and gender, and calcineurin inhibitor treatment. Each recipient's postal code was linked to a postal code area information database to extract information on housing value, income, percentage non-Europeans in the area, and urbanization level.

RESULTS

In multivariable analysis, graft survival censored for death was significantly influenced by recipient age, maximum panel reactive antibodies, HLA mismatches, donor type, donor age, and calcineurin inhibitor treatment. Patient survival was significantly influenced by recipient age, comorbidity, transplant year, and donor type. Socioeconomic factors and ethnicity did not have a significant influence on graft and patient survival.

CONCLUSIONS

Though ethnicity and socioeconomic factors do not influence survival after kidney transplantation, the favorable influence of living donor type is of paramount importance. As non-Europeans and patients with unfavorable socioeconomic variables less often receive a living donor kidney transplant, their survival may be unfavorable after all.

Morbid obesity is not an independent predictor of graft failure or patient mortality after kidney transplantation

OBJECTIVE

Obesity is often an absolute contraindication to kidney transplant, but an internal analysis of our center's recipients suggests that not all obese populations exhibit poor outcomes. We used national data to compare outcomes in select groups of morbidly obese and normal-weight recipients after kidney transplant.

DESIGN

This study was a retrospective analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing database.

SUBJECTS

The study sample consisted of 30,132 morbidly obese (body mass index [BMI] 35-40 kg/m(2)) and normal-weight (BMI 18.5-24.9 kg/m(2)) patients who underwent primary kidney-only transplantation between 2001 and 2006.

MAIN OUTCOME MEASURE

Crude 3-year graft and patient survival rates of morbidly obese and normal-weight subgroups were evaluated. Logistic regression modeling compared 3-year graft failure and patient mortality in morbidly obese and normal-weight subgroups with opposite characteristics. Kaplan-Meier survival curves were created for 3-year graft and patient survival. Cox proportional hazard regression modeling was used to determine hazards for patient and graft mortality.

RESULTS

No differences in crude graft and patient survival rates were seen between normal weight and morbidly obese recipients who were African American, diabetic, and 50 to 80 years of age. Morbidly obese recipients who were nondialysis dependent, nondiabetic, had good functional status, and received living-donor transplants had significantly lower 3-year graft failure and patient mortality risk compared with normal-weight recipients who were dialysis dependent, diabetic, had poor functional status, and received a deceased-donor transplant, respectively (P < .01). Morbidly obese recipients have significantly lower graft and patient survival curves compared with normal-weight recipients; however, multivariate regression analysis reveals that morbid obesity is not an independent predictor of graft failure or patient mortality.

CONCLUSIONS

Morbid obesity is not independently associated with graft failure or patient mortality; therefore, it should not be used as a contraindication to kidney transplantation.

Selection of induction therapy in kidney transplantation

Currently available immunosuppressive agents can be classified into three categories: induction agents, maintenance therapy, and treatment for rejection. This review article will focus on induction immunosuppression. There are three antibodies which are used for induction therapy: the lymphocyte-depleting agents - anti-thymocyte globulin and alemtuzumab, and basiliximab which is nondepleting. Historically, immunosuppressant selection was solely based on efficacy for prevention of rejection. In the current era of transplantation, it is now common practice in the transplant community to select induction therapy on the basis of risk-benefit considerations for each patient. This article will focus on the efficacy of available induction agents and the selection of induction agent based on donor and recipient risk factors.

Improved survival in heart transplant recipients in the United States: racial differences in era effect

BACKGROUND

Posttransplant survival in heart transplant recipients has progressively improved during the past 2 decades. It is unknown, however, whether the major racial groups in the United States have benefited equally.

METHODS AND RESULTS

We analyzed all primary heart transplant recipients aged ≥18 years in the United States from 1987 to 2008. We compared posttransplant survival in white, black, and Hispanic recipients in 5 successive eras (1987 to 1992, 1993 to 1996, 1997 to 2000, 2001 to 2004, 2005 to 2008). Early survival was defined as freedom from death or retransplantation during the first 6 months posttransplant. Longer-term, conditional survival was assessed in patients who survived the first 6 months. There were 29 986 (81.6%) white, 4745 (12.9%) black, and 2017 (5.5%) Hispanic patients in the study cohort. Black patients were at increased risk of early death or retransplant (hazard ratio [HR], 1.15; 95% CI, 1.05 to 1.26) in adjusted analysis. Early posttransplant survival improved (HR, 0.83; 95% CI, 0.80 to 0.87 for successive eras) equally in all 3 groups (black-era interaction, P=0.94; Hispanic-era interaction, P=0.40). Longer-term survival improved in white (HR, 0.95; 95% CI, 0.92 to 0.97 for successive eras) but not in black (HR, 1.04; 95% CI, 0.99 to 1.09) or Hispanic (HR, 1.02; 95% CI, 0.95 to 1.09) recipients, resulting in increased disparities in longer-term survival with time.

CONCLUSIONS

Early posttransplant survival has improved equally in white, black, and Hispanic heart transplant recipients. Longer-term survival has improved in white but not in black or Hispanic recipients, resulting in a more marked disparity in outcomes in the current era. These disparities warrant further investigation and targeted interventions.

Improved survival in pediatric heart transplant recipients: have white, black and Hispanic children benefited equally?

We assessed whether the improvement in posttransplant survival in pediatric heart transplant (HT) recipients during the last two decades has benefited the major racial groups in the United States equally. We analyzed all children <18 years of age who underwent their first HT in the US during 1987-2008. We compared trends in graft loss (death or retransplant) in white, black and Hispanic children in five successive cohorts (1987-1992, 1993-1996, 1997-2000, 2001-2004, 2005-2008). The primary endpoint was early graft loss within 6 months posttransplant. Longer-term survival was assessed in recipients who survived the first 6 months. The improvement in early posttransplant survival was similar (hazard ratio [HR] for successive eras 0.80, 95% confidence interval [CI] 0.7, 0.9, p = 0.24 for black-era interaction, p = 0.22 for Hispanic-era interaction) in adjusted analysis. Longer-term survival was worse in black children (HR 2.2, CI 1.9, 2.5) and did not improve in any group with time (HR 1.0 for successive eras, CI 0.9, 1.1, p = 0.57; p = 0.19 for black-era interaction, p = 0.21 for Hispanic-era interaction). Thus, the improvement in early post-HT survival during the last two decades has benefited white, black and Hispanic children equally. Disparities in longer-term survival have not narrowed with time; the survival remains worse in black recipients.