Faculty Bibliography

BACKGROUND:Body mass index of living kidney donors has increased substantially. Determining candidacy for live kidney donation among obese individuals is challenging because many donation-related risks among this subgroup remain unquantified, including even basic postdonation mortality. METHODS:We used data from the Scientific Registry of Transplant Recipients linked to data from the Centers for Medicare and Medicaid Services to study long-term mortality risk associated with being obese at the time of kidney donation among 119,769 live kidney donors (1987-2013). Donors were followed for a maximum of 20 years (interquartile range 6.0-16.0). Cox proportional hazards estimated the risk of postdonation mortality by obesity status at donation. Multiple imputation accounted for missing obesity data. RESULTS:Obese (body mass index ≥ 30) living kidney donors were more likely male, African American, and had higher blood pressure. The estimated risk of mortality 20 years after donation was 304.3/10,000 for obese and 208.9/10,000 for nonobese living kidney donors. Adjusting for age, sex, race/ethnicity, blood pressure, baseline estimated glomerular filtration rate, relationship to recipient, smoking, and year of donation, obese living kidney donors had a 30% increased risk of long-term mortality compared with their nonobese counterparts (adjusted hazard ratio: 1.32, 95% CI: 1.09-1.60, P = .006). The impact of obesity on mortality risk did not differ significantly by sex, race or ethnicity, biologic relationship, baseline estimated glomerular filtration rate, or among donors who did and did not develop postdonation kidney failure. CONCLUSION:These findings may help to inform selection criteria and discussions with obese persons considering living kidney donation.

PURPOSE OF REVIEW:We report the current state of HIV+ to HIV+ kidney transplantation in the United States and remaining challenges in implementing this practice nationally. RECENT FINDINGS:The HIV Organ Policy Equity (HOPE) Act, which was the first step in unlocking the potential of HIV+ organ donors, mandates clinical research on HIV+ to HIV+ transplantation. As of March 2019, there have been 57 HOPE donors, including both true and false positive HOPE donors resulting in more than 120 transplants. SUMMARY:The HOPE Act, signed in 2013, reversed the federal ban on the transplantation of organs from HIV+ donors into HIV+ recipients. Ongoing national studies are exploring the safety, feasibility, and efficacy of both kidney and liver transplantation in this population. If successfully and fully implemented, HIV+ to HIV+ transplantation could attenuate the organ shortage for everyone waiting, resulting in a far-reaching public health impact.

BACKGROUND:United States transplant centers are required to report follow-up data for living kidney donors for 2 years post-donation. However, living kidney donor (LKD) follow-up is often incomplete. Mobile health (mHealth) technologies could ease data collection burden but have not yet been explored in this context. METHODS:We conducted semi-structured in-depth interviews with a convenience sample of 21 transplant providers and thought leaders about challenges in LKD follow-up, and the potential role of mHealth in overcoming these challenges. RESULTS:Participants reported challenges conveying the importance of follow-up to LKDs, limited data from international/out-of-town LKDs, and inadequate staffing. They believed the 2-year requirement was insufficient, but expressed difficulty engaging LKDs for even this short time and inadequate resources for longer-term follow-up. Participants believed an mHealth system for post-donation follow-up could benefit LKDs (by simplifying communication/tasks and improving donor engagement) and transplant centers (by streamlining communication and decreasing workforce burden). Concerns included cost, learning curves, security/privacy, patient language/socioeconomic barriers, and older donor comfort with mHealth technology. CONCLUSIONS:Transplant providers felt that mHealth technology could improve LKD follow-up and help centers meet reporting thresholds. However, designing a secure, easy to use, and cost-effective system remains challenging.

BACKGROUND:Frail kidney transplant (KT) recipients have higher risk of adverse post-KT outcomes. Yet, there is interest in measuring frailty at KT evaluation and then using this information for post-KT risk stratification. Given long wait times for KT, frailty may improve or worsen between evaluation and KT. Patterns, predictors, and post-KT adverse outcomes associated with these changes are unclear. METHODS:Five hundred sixty-nine adult KT candidates were enrolled in a cohort study of frailty (November 2009-September 2017) at evaluation and followed up at KT. Patterns of frailty transitions were categorized as follows: (1) binary state change (frail/nonfrail), (2) 3-category state change (frail/intermediate/nonfrail), and (3) raw score change (-5 to 5). Adjusted Cox proportional hazard and logistic regression models were used to test whether patterns of frailty transitions were associated with adverse post-KT outcomes. RESULTS:Between evaluation and KT, 22.0% became more frail, while 24.4% became less frail. Black race (relative risk ratio, 1.98; 95% confidence interval [CI], 1.07-3.67) was associated with frail-to-nonfrail transition, and diabetes (relative risk ratio, 2.56; 95% CI, 1.22-5.39) was associated with remaining stably frail. Candidates who became more frail between 3-category states (hazard ratio, 2.27; 95% CI, 1.11-4.65) and frailty scores (hazard ratio, 2.36; 95% CI, 1.12-4.99) had increased risk of post-KT mortality and had higher odds of length of stay ≥2 weeks (3-category states: odds ratio, 2.02; 95% CI, 1.20-3.40; frailty scores: odds ratio, 1.92; 95% CI, 1.13-3.25). CONCLUSIONS:Almost half of KT candidates experienced change in frailty between evaluation and KT, and those transitions were associated with mortality and longer length of stay. Monitoring changes in frailty from evaluation to admission may improve post-KT risk stratification.

Background/UNASSIGNED:Limited data are available regarding clinical implications of lower renal function after living kidney donation. We examined a novel integrated database to study associations between postdonation estimated glomerular filtration rate (eGFR) and use of antihypertensive medication (AHM) treatment after living kidney donation. Methods/UNASSIGNED:) between AHM use and postdonation eGFR levels (random effect) with fixed effects for baseline donor factors. Results/UNASSIGNED:). Conclusions/UNASSIGNED:This novel linkage illustrates the ability to identify postdonation kidney function and associate it with clinically meaningful outcomes; lower eGFR after living kidney donation is a correlate of AHM treatment requirements. Further work should define relationships of postdonation renal function, hypertension, and other morbidity measures.

BACKGROUND AND OBJECTIVES:Hypertension in older kidney donor candidates is viewed as safe. However, hypertension guidelines have evolved and long-term outcomes have not been explored. We sought to quantify the 15-year risk of ESKD and mortality in older donors (≥50 years old) with versus those without hypertension. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:A United States cohort of 24,533 older donors from 1999 to 2016, including 2265 with predonation hypertension, were linked to Centers for Medicare and Medicaid Services data and the Social Security Death Master File to ascertain ESKD development and mortality. The exposure of interest was predonation hypertension. From 2004 to 2016, hypertension was defined as documented predonation use of antihypertensive therapy, regardless of systolic BP or diastolic BP; from 1999 to 2003, when there was no documentation of antihypertensive therapy, hypertension was defined as predonation systolic BP ≥140 or diastolic BP ≥90 mm Hg. RESULTS:=0.34). CONCLUSIONS:Compared with older donors without hypertension, older donors with hypertension had higher risk of ESKD, but not mortality, for 15 years postdonation. However, the absolute risk of ESKD was small.

BACKGROUND:Cognitive impairment is common in patients with end-stage renal disease and is associated with poor outcomes on dialysis. We hypothesized that cognitive impairment might be associated with an increased risk of all-cause graft loss (ACGL) in kidney transplant (KT) recipients. METHODS:Using the Modified Mini-Mental State (3MS) examination, we measured global cognitive function at KT hospital admission in a prospective, 2-center cohort of 864 KT candidates (August 2009 to July 2016). We estimated the association between pre-KT cognitive impairment and ACGL using Cox regression, adjusting for recipient, donor, and transplant factors. RESULTS:In living donor KT (LDKT) recipients, the prevalence was 3.3% for mild impairment (60 ≤ 3MS < 80) and 3.3% for severe impairment (3MS < 60). In deceased donor KT (DDKT) recipients, the prevalence was 9.8% for mild impairment and 2.6% for severe impairment. The LDKT recipients with cognitive impairment had substantially higher ACGL risk than unimpaired recipients (5-year ACGL: 45.5% vs 10.6%; P < 0.01; adjusted hazard ratio [aHR] any impairment, 5.40 (95% confidence interval [CI], 1.78-16.34; P < 0.01); aHR severe impairment, 5.57 (95% CI, 1.29-24.00; P = 0.02). Similarly, DDKT recipients with severe impairment had higher ACGL risk than recipients without severe impairment (5-year ACGL, 53.0% vs 24.2%; P = 0.04); aHR severe impairment, 2.92 (95% CI, 1.13-7.50; P = 0.03). CONCLUSIONS:Given the elevated risk of ACGL among KT recipients with cognitive impairment observed in this 2-center cohort, research efforts should explore the mechanisms of graft loss and mortality associated with cognitive impairment and identify potential interventions to improve posttransplant survival.

Livers from older donors (OLDs; age ≥70) are risky and often declined; however, it is likely that some candidates will benefit from OLDs versus waiting for younger ones. To characterize the survival benefit of accepting OLD grafts, we used 2009-2017 SRTR data to identify 24 431 adult liver transplant (LT) candidates who were offered OLD grafts eventually accepted by someone. Outcomes from the time-of-offer were compared between candidates who accepted an OLD graft and matched controls within MELD ± 2 who declined the same offer. Candidates who accepted OLD grafts (n = 1311) were older (60.5 vs. 57.8 years, P < .001), had a higher median MELD score (25 vs. 22, P < .001), and were less likely to have hepatitis C cirrhosis (14.9% vs. 31.2%, P < .001). Five-year cumulative mortality among those who accepted versus declined the same OLD offer was 23.4% versus 41.2% (P < .001). Candidates who accepted OLDs experienced an almost twofold reduction in mortality (aHR:_0.45 0.52_0.59 , P < .001) compared to those who declined the same offer, especially among the highest MELD (35-40) candidates (aHR:_0.10 0.24_0.55 , P = .001). Accepting an OLD offer provided substantial long-term survival benefit compared to waiting for a better organ offer, notably among candidates with MELD 35-40. Providers should consider these benefits as they evaluate OLD graft offers.

In the United States, kidney donation from international (noncitizen/nonresident) living kidney donors (LKDs) is permitted; however, given the heterogeneity of healthcare systems, concerns remain regarding the international LKD practice and recipient outcomes. We studied a US cohort of 102 315 LKD transplants from 2000-2016, including 2088 international LKDs, as reported to the Organ Procurement and Transplantation Network. International LKDs were more tightly clustered among a small number of centers than domestic LKDs (Gini coefficient 0.76 vs 0.58, P < .001). Compared with domestic LKDs, international LKDs were more often young, male, Hispanic or Asian, and biologically related to their recipient (P < .001). Policy-compliant donor follow-up was substantially lower for international LKDs at 6, 12, and 24 months postnephrectomy (2015 cohort: 45%, 33%, 36% vs 76%, 71%, 70% for domestic LKDs, P < .001). Among international LKDs, Hispanic (aOR = _0.23 0.36_0.56 , P < .001) and biologically related (aOR = _0.39 0.59_0.89 , P < .01) donors were more compliant in donor follow-up than white and unrelated donors. Recipients of international living donor kidney transplant (LDKT) had similar graft failure (aHR = _0.78 0.89_1.02 , P = .1) but lower mortality (aHR = _0.53 0.62_0.72 , P < .001) compared with the recipients of domestic LDKT after adjusting for recipient, transplant, and donor factors. International LKDs may provide an alternative opportunity for living donation. However, efforts to improve international LKD follow-up and engagement are warranted.