Donor-recipient relationships in African American vs. Caucasian live kidney donors

Reeves‐Daniel A, Bailey A, Assimos D, Westcott C, Adams PL, Hartmann EL, Rogers J, Farney AC, Stratta RJ, Daniel K, Freedman BI. Donor–recipient relationships in African American vs. Caucasian live kidney donors.
Clin Transplant 2011: 25: E487–E490. © 2011 John Wiley & Sons A/S. Abstract: Purpose: The purpose of the study was to characterize differences in donor and recipient relationships between African American (AA) and Caucasian living kidney donors. Methods: Data from all successful living kidney donors at a single institution between 1991 and 2009 were reviewed. Relationships between donor and recipient were categorized and between‐group comparisons performed. Results: The study sample consisted of 73 (18%) AA and 324 Caucasian living kidney donors. The distribution of donor–recipient relationships differed significantly between AA and Caucasians. AA donors were more likely to be related to the recipient (88% vs. 74%, p = 0.007) than Caucasians. AA donors were more likely to participate in child to parent donation and were less likely to participate in parent to child donation or to donate to unrelated individuals. Sibling and spousal donations were similar in both groups. Caucasian donors were more likely to be unrelated to the recipient than AA donors. Conclusions: Differences exist in donor–recipient relationships between AA and Caucasian living kidney donors. Future studies exploring cultural differences and family dynamics may provide targeted recruitment strategies for AA and Caucasian living kidney donors. Living unrelated kidney transplantation appears to be a potential growth area for living kidney donation in AA.     

Short‐term kidney transplant outcomes among African American recipients do not predict long‐term outcomes: donor pair analysis

Keith D, Patrie JT. Short‐term kidney transplant outcomes among African‐American recipients do not predict long‐term outcomes: donor pair analysis.
Clin Transplant 2011: 25: 69–76. © 2010 John Wiley & Sons A/S. Abstract: African American (AA) renal transplant recipients have poorer graft survival compared to other racial and ethic groups. This study was undertaken to determine whether pre‐transplant factors and events occurring in the first six months post‐transplant were predictive of the poorer long‐term outcomes in AA recipients. To control for kidney quality, a paired analysis of deceased donor kidneys in which one donor kidney was transplanted into an adult AA recipient and the other was transplanted into an adult Caucasian was undertaken. Cox proportional hazard modeling was used to determine the impact of outcome variables at six months. Outcomes at six months among the paired recipients were very similar for graft and patient survival, and estimated glomerular filtration rate (GFR). Less than 10% of difference in long‐term outcomes was explained by differences in the pre‐transplant covariates and events in the first six months. Causes of graft failure after six months revealed a two to three times higher rate of chronic allograft nephropathy (CAN) and late acute rejection among AA. In conclusion, early outcomes after kidney transplant did not predict the poor long‐term graft survival among AA, and AA recipients appear to be more prone to graft loss because of CAN and late acute rejection.     

Impact of race and gender on live kidney donation

Abstract: Background: African Americans (AA) and women are less likely to receive a live kidney donor (LKD) transplant than Caucasians or men. Reasons for non‐donation are poorly understood. Methods: A retrospective review of 541 unsuccessful LKD was performed to explore reasons for non‐donation and to assess for racial and/or gender differences. Results: We identified 138 AA and 385 Caucasian subjects who volunteered but did not successfully donate. Females (58.2%) were more likely to be excluded than males due to reduced renal function (glomerular filtration rate < 85 mL/min, 7.9% vs. 0.9%, p < 0.0001) or failure to complete the evaluation (6.4% vs. 1.8%, p = 0.01). AA were more commonly excluded due to obesity (body mass index ≥ 32 kg/m²; 30.4% AA vs. 16.6% Caucasian, p = 0.0005) or failure to complete the evaluation (12.3% AA vs. 1.8% Caucasian, p < 0.0001) whereas Caucasians were more often excluded due to kidney stones (1.5% AA vs. 7.3% Caucasian, p = 0.01). Conclusions: Significantly different reasons for exclusion of LKD exist between potential Caucasian and AA LKD, particularly among women. Among the differences that we observed are potentially modifiable barriers to donation including obesity and failure to complete the donor evaluation. A further understanding of these barriers may help point to strategies for more effective recruitment and successful LKD.     

Medical Outcomes in African American Live Kidney Donors: A Matched Cohort Study

It is uncertain if live kidney donation increases future risk of hypertension and kidney disease in African Americans. We conducted a cohort study across two transplant centers enrolling African Americans who donated between 1993 and 2006. A comparison group of African American nondonors were selected from healthy participants in the Coronary Artery Risk Development in Young Adults (CARDIA) prospective cohort study. A total of 103 donors and 235 matched nondonors were assessed at mean ( ± SD) of 6.8 ± 2.3 and 6.4 ± 2.2 years after donation or cohort entry, respectively. The primary outcome was risk of hypertension in donors at follow‐up. The secondary outcomes were proportion of donors with eGFR <60 mL/min/1.73 m2 and microalbuminuria. Hypertension risk was higher in donors compared to nondonors (42/103 [40.8%] vs. 42/235 [17.9%]), absolute risk difference 22.9% (95% confidence interval 12.2–33.6%) and relative risk 2.4 (95% confidence interval 1.7–3.4). Of the 42 donors with hypertension, 22 (52.4%) were untreated. Sixteen donors (15.5%) had an eGFR <60 mL/min/1.73 m², 6 (5.8%) had microalbuminuria and none were on dialysis. Our retrospective study shows that live kidney donation is associated with increased risk of hypertension in African Americans and emphasizes the importance of donor follow‐up.     

Long‐term risk for kidney donors with hypertension at donation – a retrospective cohort study

In the general population, small increases in blood pressure are associated with increased mortality. In kidney donors this association is less certain. We therefore assessed long‐term overall and cardiovascular mortality in donors who were hypertensive at the time of donation compared with normotensive donors. Hypertension was defined as blood pressure >140/90 mmHg or use of antihypertensive drugs. Adequate records available in 2131 donors revealed that 140 were hypertensive and 1991 were normotensive. Multivariable regression analyses were performed for overall and cardiovascular mortality. Hypertensive donors were significantly older (mean 57.7 vs. 46.9 years), more were males (44.3% vs. 41.5%), had higher body mass index (26.4 vs. 24.7) and lower estimated glomerular filtration rate (91.8 vs. 101.2 ml/min/1.73 m²). After a median observation time of 20.8 years (interquartile range 11) 71 hypertensive donors had died and 26 of the deaths were cardiovascular. Multivariable analysis did not suggest a generalizable association between hypertension and long‐term overall mortality [hazard ratio (HR) 1.1, 95% confidence interval (CI) 0.9–1.5, P = 0.34] or cardiovascular mortality (HR 1.1, 95% CI 0.7–1.8, P = 0.55). These data may support the use of older healthy kidney donors with hypertension at donation.     

One‐ and five‐year follow‐ups on blood pressure and renal function in kidney donors

It is considered safe to donate a kidney if internationally accepted medical criteria are fulfilled. However, some donors have encountered hypertension, proteinuria and impaired renal function after donation. The study was based on retrospective data on 908 donors, donating in the period 1997–2007. Preoperative and follow‐up data were collected from patient files and the Norwegian Living Donor Registry. Follow‐up data were available for 665 donors at 1 year after donation, and 256 donors at 5 years after donation. We calculated the estimated glomerular filtration rate (eGFR) using the four variable Modification of Diet in Renal Disease equation. At 1 and 5 years after donation, the prevalence of hypertension was 11.7% and 27.1% respectively compared to 2.6% before donation. Proteinuria was present in 3.3% and 1.6% at 1 and 5 years. Mean eGFR was 56.1 ± 10.8 ml/min/1.73 m² at 1 year and 61.0 ± 11.8 ml/min/1.73 m² at 5 years. Mean blood pressure was 122.5 ± 10.6/76.2 ± 7.5 mmHg at donation (n = 908), 124.3 ± 14.2/77.9 ± 8.2 mmHg at 1‐year (n = 649) and 127.2 ± 15.4/78.8 ± 8.3 mmHg at 5‐year follow‐ups (n = 247). We found no evidence of further decline in renal function beyond the initial decrement following nephrectomy.     

Panning for gold: screening for potential live kidney donors.

BACKGROUND: Living donation is one method of addressing the gulf between supply and demand for kidney transplants. However, few manage to complete the extensive work up procedure. This study reviews the reasons for failure to complete the live donor renal assessment and suggests options, which may improve the situation. METHODS: Retrospective analysis of data collected over 5 years between 1997 and 2001 of all potential live donors entering the assessment programme. RESULTS: 189 (103 female, 86 male) potential donors entered the assessment process. Thirty-four (18%) actually donated comprising 17 (50%) siblings, nine (26%) parents and eight (24%) unrelated donors. Of the 155 who did not donate, 46 (30%) had blood group or immunological incompatibility and 42 (27%) withdrew. Twenty-three (15%) were medically unfit, mostly due to cardiovascular disease and 16 (10%) had insufficient renal function for safe donation. CONCLUSION: Live donor transplantation offers an attractive source of high quality organs, but considerable time and effort is required to realize this. Manipulation of immunological incompatibility, psychological assessment and counselling of those likely to withdraw may significantly enhance the yield. Support should also be provided for those unable to donate for whatever reason.     

Improving institutional fairness to live kidney donors: donor needs must be addressed by safeguarding donation risks and compensating donation costs

The number of kidney transplants from live donors is increasing worldwide, yet donor needs have not been satisfactorily addressed in either developed or developing countries. This paper argues that unmet donor needs are unfair to live kidney donors in two ways. First, when safeguards against the risks of donation are insufficient, live donation can impair the donor's health and thus his or her fair opportunities to access jobs and offices and to function as a free and equal citizen more generally. Secondly, when the financial costs of donation are not fully compensated, operational fairness (associated with the nephrectomy event) is compromised for the donor. The donor assumes the risks of a nontherapeutic intervention--for the good of the recipient and society--and should not have to incur costs for donating. Based on a systematic analysis of unmet donor needs in developed and developing countries, context-relative measures to improve institutional fairness to live kidney donors are delineated in this paper. The identified ways of safeguarding donation risks and compensating donation costs are not merely means to removing disincentives for donation and increasing donation rates. They are essential for preserving institutional fairness in the health care of the live kidney donor.     

Tacrolimus dose requirements in African‐American and Caucasian kidney transplant recipients on mycophenolate and prednisone

Racial differences among kidney transplant recipients may impact the total daily tacrolimus dose required to achieve therapeutic tacrolimus concentrations. Previous studies suggest that African Americans require higher doses to achieve similar therapeutic drug concentrations compared with Caucasians. Data were collected on a total of 147 de novo kidney transplant recipients. Tacrolimus total daily dose (TDD) requirements (mg/kg/d) and tacrolimus concentrations were retrospectively reviewed at discharge and at days 30, 60, and 90 after transplant. TDD requirements in African‐American and Caucasian patients were 0.14 mg/kg/d and 0.11 mg/kg/d, respectively (p = 0.005), at day 30. TDD requirements at day of hospital discharge and days 60 and 90 following transplant were significantly higher in African‐American patients vs. Caucasian patients, with similar tacrolimus concentrations at all time points. This study suggests that when compared to Caucasians, African Americans require significantly higher TDD of tacrolimus to achieve similar tacrolimus concentrations. These findings provide transplant clinicians with a sense of certainty to more rapidly titrate daily tacrolimus doses in African‐American patients to achieve therapeutic concentrations.     

Optimizing left‐sided live kidney donation: hand‐assisted retroperitoneoscopic as alternative to standard laparoscopic donor nephrectomy

Laparoscopic donor nephrectomy (LDN) is less traumatic and painful than the open approach, with shorter convalescence time. Hand‐assisted retroperitoneoscopic (HARP) donor nephrectomy may have benefits, particularly in left‐sided nephrectomy, including shorter operation and warm‐ischemia time (WIT) and improved safety. We evaluated outcomes of HARP alongside LDN. From July 2006 to May 2008, 20 left‐sided HARP procedures and 40 left‐sided LDNs were performed. Intra and postoperative data were prospectively collected and analysis on outcome of both techniques was performed. More female patients underwent HARP compared to LDN (75% vs. 40%, P = 0.017). Other baseline characteristics were not significantly different. Median operation time and WIT were shorter in HARP (180 vs. 225 min, P = 0.002 and 3 vs. 5 min, P = 0.007 respectively). Blood loss did not differ (200 ml vs.150 ml, P = 0.39). Intra and postoperative complication rates for HARP and LDN (respectively 10% vs. 25%, P = 0.17 and 5% vs. 15%, P = 0.25) were not significantly different. During median follow‐up of 18 months estimated glomerular filtration rates in donors and recipients and graft‐ and recipient survival did not differ between groups. Hand‐assisted retroperitoneoscopic donor nephrectomy reduces operation and warm ischemia times, and provides at least equal safety. Hand‐assisted retroperitoneoscopic may be a valuable alternative for left‐sided LDN.     

Health outcomes among non‐Caucasian living kidney donors: knowns and unknowns

The growth in living kidney donation has been accompanied by greater racial diversity. Most information on post‐donation health comes from single‐center studies of dominantly Caucasian cohorts. Recent linkage of U.S. donor registration data with death records demonstrated higher mortality risks among African American donors, but importantly, no differences in death compared with demographically matched, healthy controls. Within the donor population, some recent studies have also identified higher likelihoods of post‐donation hypertension, diabetes mellitus and kidney failure in African American and Hispanic donors. Thus, based on concerns for higher risks of long‐term end‐organ damage, it may be reasonable to consider race within the living donor selection process, such as use of more stringent exclusion criteria among non‐Caucasian living donors with baseline elevated blood pressure. Recently identified associations of coding variants in the apolipoprotein L1 (APOL1) gene with nondiabetic renal failure in African Americans raise promise of APOL1 genotyping as a novel tool for risk stratifying African American potential donors, but more data are needed to understand implications for post‐donation outcomes. To tailor counseling and informed consent, focused attention to long‐term medical outcomes among non‐Caucasian living donors is needed, and should include assembly of healthy non‐donor controls for assessment of attributable risks of donation.     

Long‐term outcome of highly sensitized African American patients transplanted with deceased donor kidneys

Undertaking transplantation in highly sensitized African American (AA) patients as transplant recipients represents a unique challenge. We retrospectively compared the outcomes of AA with non‐African American (NAA) patients who had panel reactive antibody >80% and received deceased donor (DD) kidneys by virtual crossmatch. Immunosuppressive regimen included basiliximab induction and tacrolimus, mycophenolate acid and steroids maintenance. Among 835 consecutive transplants from 1998 to 2007, 142 (17%) were sensitized patients including 89 (16.6%) AA and 53 (17.7%) NAA patients. The AA group had similar 5‐year incidence of acute rejection as NAA group (21.4% vs. 26.4%, P = 0.25). Kaplan–Meier estimated graft survival at 1, 3 and 5 years were 91%, 85% and 82% in AA group, and 94%, 79% and 71% in NAA group (P = 0.08). The death‐censored graft survival at 1, 3, and 5 years were 93%, 86% and 84% in AA group, and 96%, 83% and 78% in NAA group (P = 0.11). The 1, 3, and 5 years patient survivals were 93%, 88% and 85% in AA group, and 96%, 96% and 94% in NAA group (P = 0.17). Highly sensitized AA patients could be transplanted with DD kidneys at a similar rate as NAA patients, and they may not have a higher incidence of rejection or an inferior graft survival than NAA patients.     

Race and renal function early after live kidney donation: an analysis of the United States Organ Procurement and Transplantation Network Database

Doshi M, Garg AX, Gibney E, Parikh C. Race and renal function early after live kidney donation: an analysis of the United States Organ Procurement and Transplantation Network database.
Clin Transplant 2010 DOI: 10.1111/j.1399‐0012.2010.01209.x.
© 2010 John Wiley & Sons A/S. Abstract: Among Americans, the risk for kidney disease is higher in individuals of African descent (AA) when compared with Caucasians. We considered whether there are similar racial differences in kidney function soon after donor nephrectomy. Of the 31 928 live kidney donors that donated between the years 2000 and 2005, 16 996 (53%) had post‐donation serum creatinine recorded at a mean follow‐up of 156 d (range 1–1410 d). A total of 14 525 (85%) were Caucasians and 2471 (15%) were AA. When compared with Caucasians, AA donors were more likely to be younger, heavier, and male, had a higher baseline serum creatinine and a shorter duration of follow‐up. After accounting for these differences, the serum creatinine after donation and fractional rise in serum creatinine after donation were similar between the two groups (AA vs. Caucasian donors, 1.3 ± 0.3 vs. 1.2 ± 0.3 mg/dL; 53% vs. 45%) and the post‐donation estimated glomerular filtration rate was also similar (57.2 ± 0.6 vs. 56.0 ± 0.2 mL/min per 1.73 m²). We observed no major clinical difference in glomerular filtration rate and ability to compensate for loss of renal mass soon after live kidney donation between Caucasian and AA donors.     

Kidney transplant from uncontrolled donation after circulatory death donors maintained by nECMO has long‐term outcomes comparable to standard criteria donation after brain death

Uncontrolled donation after circulatory death (uDCD) increases organ availability for kidney transplant (KT) with short‐term outcomes similar to those obtained from donation after brain death (DBD) donors. However, heterogeneous results in the long term have been reported. We compared 10‐year outcomes between 237 KT recipients from uDCD donors maintained by normothermic extracorporeal membrane oxygenation (nECMO) and 237 patients undergoing KT from standard criteria DBD donors during the same period at our institution. We further analyzed risk factors for death‐censored graft survival in the uDCD group. Delayed graft function (DGF) was more common in the uDCD group (73.4% vs 46.4%; P < .01), although glomerular filtration rates at the end of follow‐up were similar in the 2 groups. uDCD and DBD groups had similar rates for 10‐year death‐censored graft (82.1% vs 80.4%; P = .623) and recipient survival (86.2% vs 87.6%; P = .454). Donor age >50 years was associated with graft loss in the uDCD group (hazard ratio: 1.91; P = .058), whereas the occurrence of DGF showed no significant effect. uDCD KT under nECMO support resulted in similar graft function and long‐term outcomes compared with KT from standard criteria DBD donors. Increased donor age could negatively affect graft survival after uDCD donation.     

Characteristics of kidney donors and recipients in Iranian kidney market: Evidence from Mashhad

The Iranian model of kidney transplantation is an example of a regulated living unrelated renal donation. In this paper, we collected and analyzed a unique dataset of 436 paired kidney donors and recipients, including their characteristics and the realized price of a kidney in Mashhad. As opposed to the global picture of kidney donation, we find that women are less likely to donate and more likely to receive a kidney. Moreover, the average price of a kidney amounts less than 2 years of work with the minimum level of wage.     

Antihypertensive pharmacotherapy and long‐term outcomes in pediatric kidney transplantation

Hypertension (HTN) is common in pediatric recipients following kidney transplantation (KT). We retrospectively assessed the impact of HTN on long‐term (>10‐yr) outcomes in pediatric KT recipients (aged < 18 yr) at our center. Two hundred and ninety‐three pediatric KT recipients (83% living donor [LD]) with graft survival (GS) for ≥5 yr were studied. HTN was defined by antihypertensive medication use at five yr post‐KT. One hundred and sixty (55%) recipients did not have HTN, and 133 (45%) had HTN at five yr post‐KT. There were no differences in actuarial patient survival between cohorts. Actuarial GS at 15 and 20 yr was 68% and 53% for recipients without HTN, and 53% and 33% for recipients with HTN (p = 0.006). Among LD recipients using one antihypertensive, GS at 15 yr was 100% for those using an angiotensin‐converting enzyme inhibitor (ACEI) and 44% for those not using an ACEI (p = 0.04). Among these recipients, HTN treated with no ACEI was a significant risk factor for graft failure at >5 yr (hazard ratio [HR] = 2.5, p = 0.02), but HTN treated with an ACEI was not (HR = 0.6, p = 0.7). HTN at five yr post‐KT is associated with poorer long‐term GS in pediatric recipients, but ACEI therapy may enable better outcomes and should be studied further.     

Long-term kidney transplant outcome in obese patients in a predominantly African American population

The impact of obesity on long-term kidney transplant outcome has largely been studied in non-African American patients. This study seeks to determine differences in outcome between obese and non-obese patients after kidney transplantation, in a predominantly African American population. We reviewed 642 adult renal transplant recipients who received their transplants at SUNY Downstate Medical Center between 1998 and 2007. Sixty-six percent of the patients studied were African American. The patients were divided into five groups according to their BMI status: underweight <20, normal 20-24.9, overweight 25-29.9, obese 30-34.9, and morbidly obese ≥35. There were no differences in race, gender, cytomegalovirus infection, type of transplant, panel-reactive antibody, retransplant status, flow cytometry cross-match results, mycophenolate mofetil therapy, and total HLA mismatch status. The mean discharge serum creatinine in the morbidly obese group was significantly higher than in other groups (p < 0.001). The difference in creatinine level disappeared at six wk and six months (p > 0.5), respectively. Acute rejection rates, delayed graft function, graft survival, and patient survival were not different between the groups. The findings from this large single-center study suggest that obese and morbidly obese patients had similar outcomes compared to other weight groups. Obese and morbidly obese African American patients should not be excluded from kidney transplantation on the basis of weight alone.     

Short‐term outcomes of deceased donor renal transplants of HCV uninfected recipients from HCV seropositive nonviremic donors and viremic donors in the era of direct‐acting antivirals

The United States opioid use epidemic over the past decade has coincided with an increase in hepatitis C virus  (HCV) positive donors. Using propensity score matching, and the Organ Procurement Transplant Network data files from January 2015 to June 2019, we analyzed the short‐term outcomes of adult deceased donor kidney transplants of HCV uninfected recipients with two distinct groups of HCV positive donors (HCV seropositive, nonviremic n = 352 and viremic n = 196) compared to those performed using HCV uninfected donors (n = 36 934). Compared to the reference group, the transplants performed using HCV seropositive, nonviremic and viremic donors experienced a lower proportion of delayed graft function (35.2 vs 18.9%; P < .001 [HCV seropositive, nonviremic donors] and 36.2 vs 16.8% ;  P < .001[HCV viremic donors]). The recipients of HCV viremic donors had better allograft function at 6 months posttransplant (eGFR [54.1 vs 68.3 mL/min/1.73 m2; P = .004]. Furthermore, there was no statistical difference in the overall graft failure risk at 12 months posttransplant by propensity score matched multivariable Cox proportional analysis (HR =  0.60, 95% CI  0.23 to  1.29 [HCV seropositive, nonviremic donors] and HR =  0.85, 95% CI 0.25 to  2.96 [HCV viremic donors]). Further studies are required to determine the long‐term outcomes of these transplants and address unanswered questions regarding the use of HCV viremic donors.