Edmund Huang

Risk factors for development of new-onset diabetes mellitus after kidney transplantation.

Background. New-onset diabetes mellitus after kidney transplantation (NODM) is an important co morbid condition that is associated with inferior graft and patient survival. The objective of this study was to identify donor, recipient and transplant factors, and choices of immunosuppression associated with development of NODM using Organ Procurement Transplant Network/United Network of Organ Sharing database (OPTN/UNOS). Methods. From January 2004 to December 2005, 15,309 adult kidney transplants alone with at least one follow-up report as of March 2006 were identified in the OPTN/UNOS database. Among these, 1,581 patients developed NODM during the follow-up period. We examined the risk factors of NODM using multivariate Cox regression analysis using the time to diagnosis of NODM as a time-varying end point. Other events such as graft loss, patient death, and lost to follow-up were censored. Results. NODM was reported in 10% in our study population with mean follow-up time of 306 days. After adjusting for other known factors, independent factors associated with the development of NODM included recipient age (29% increase of relative risk [RR] for every 10-year age increment), obesity (RR=1.39 for body mass index [BMI] 25–30 and RR=1.85 for BMI>30 vs. BMI<25), tacrolimus use (RR=1.50), hepatitis C virus (HCV) positivity (RR=1.42), and African-American recipients (RR=1.32). Alemtuzumab was associated with a lower risk of NODM (RR=0.52). Discussion. Using OPTN/UNOS database, we identified risk factors for development of NODM. Some of these factors are potentially modifiable, including obesity, HCV infection, and the use of tacrolimus. Clinical trials are needed to assess whether modifying these “modifiable risk factors” will indeed prevent NODM.

Living Donor Kidney Versus Simultaneous Pancreas-Kidney Transplant in Type I Diabetics: An Analysis of the OPTN/UNOS Database

BACKGROUND AND OBJECTIVES Transplant options for type I diabetics with end-stage renal disease include simultaneous pancreas-kidney (SPKT), living donor kidney (LDKT), and deceased donor kidney transplant (DDKT). It is unclear whether SPKT offers a survival benefit over LDKT in the current era of transplantation. The authors compared outcomes of kidney transplant recipients with type I diabetes using data from the Organ Procurement and Transplant Network/United Network for Organ Sharing. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Adult (age 20 to 59) type I diabetics who received a solitary first-time kidney transplant between 2000 and 2007 were studied. Outcomes included overall kidney graft and patient survival. Multivariate analysis was performed using a stepwise Cox proportional hazards model. RESULTS Kidney graft survival was better for recipients of LDKT compared with SPKT (P = 0.008), although patient survival was similar (P = 0.346). On multivariate analysis, LDKT was associated with lower adjusted risks over 72 mo follow-up of kidney graft failure (HR 0.71; 95% CI 0.61 to 0.83) and patient death (HR 0.78; 95% CI 0.65 to 0.94) versus SPKT. Compared with DDKT, SPKT had superior unadjusted kidney graft and patient survival, partly due to favorable SPKT donor and recipient factors. CONCLUSIONS Despite more transplants from older donors and among older recipients, LDKT was associated with superior outcomes compared with SPKT and was coupled with the least wait time and dialysis exposure. LDKT utilization should be considered in all type I diabetics with an available living donor, particularly given the challenges of ongoing organ shortage.

Age and the Associations of Living Donor and Expanded Criteria Donor Kidneys With Kidney Transplant Outcomes

BACKGROUND Recent studies show a survival advantage with kidney transplant in elderly patients compared with those on dialysis therapy. STUDY DESIGN In our present study, we examined and compared the association of expanded criteria donor (ECD) kidney and living kidney donation with the outcome of kidney transplant across different ages, including elderly recipients. SETTING & PARTICIPANTS Using the Scientific Registry of Transplant Recipients, we identified 145,470 adult kidney transplant patients. Mortality and death-censored transplant failure risks were estimated by Cox proportional regression analyses during follow-up with a median of 3.9 years. PREDICTORS ECD kidney and living kidney donation and age compared with others. OUTCOMES Mortality and death-censored transplant failure risk. RESULTS Patients were aged 45 ± 16 years and included 40% women and 19% patients with diabetes. Compared with transplant recipients 55 to younger than 65 years, the fully adjusted death-censored transplant failure risk was higher in patients 75 years and older (HR, 1.30; 95% CI, 1.09-1.56), 35 to younger than 55 years (HR, 1.13; 95% CI, 1.08-1.17), and 18 to younger than 35 years (HR, 1.64; 95% CI, 1.57-1.71). Compared with non-ECD kidneys, ECD kidneys were significant predictors of mortality in nonelderly patients (18-<35 years: HR, 1.46 [95% CI, 1.19-1.77]; 35-<55 years: HR, 1.23 [95% CI, 1.14-1.32]; and 55-<65 years: HR, 1.26 [95% CI, 1.15-1.38]) and patients 65 to younger than 70 years (HR, 1.20; 95% CI, 1.05-1.36), but not in other groups of elderly patients (HRs of 1.12 [95% CI, 0.93-1.36] for 70-<75 years and 1.04 [95% CI, 0.74-1.47] for ≥75 years). Similar results were found for risk of transplant loss. Compared with deceased donor kidneys, a living donor kidney was associated with better survival in all age groups and lower transplant loss risk in patients younger than 70 years. LIMITATIONS Unmeasured confounders cannot be adjusted for. CONCLUSIONS For deceased donors, ECD kidneys are not associated with increased mortality or transplant failure in recipients older than 70 years. For all types of donors, the persistent association between living donor kidneys and lower all-cause mortality across all ages suggests that, if possible, elderly patients gain longevity from living donor kidney transplant.

Kidney Transplantation in the Elderly

There is an increase in the older incident end-stage renal disease population that is associated with an increasing prevalence of end-stage renal disease in the United States. This trend is paralleled by an increasing rate of kidney transplantation in the elderly. Although patient survival is lower in older versus younger kidney recipients, the elderly benefit from a reduction in mortality rate and improved quality of life with transplantation compared with dialysis. Immunologic, physiologic, and psychosocial factors influence transplant outcomes and should be recognized in the care of the elderly transplant patient. In this review, we discuss transplantation in the elderly patient, particularly the topics of access to transplantation, patient and graft survival, the impact of donor quality on transplant outcomes, immunology and immunosuppression of aging, and ethical considerations in the development of an equitable organ allocation scheme.

Intermediate-term outcomes associated with kidney transplantation in recipients 80 years and older: an analysis of the OPTN/UNOS database.

Background. An increasing number of patients 80 years and older have received a kidney transplant in the United States, but their outcomes are not well described. Using Organ Procurement and Transplantation Network/United Network of Organ Sharing data, outcomes of recipients 80 years and older were evaluated. Methods. Thirty-one thousand one hundred seventy-nine elderly recipients defined by age 60 years and older receiving kidney transplants from 2000 to 2008 were stratified: ages 60 to 69 years (n=24,877), 70 to 79 years (n=6,103), and 80 years and older (n=199). Cox regression models were used to compare patient, graft, and death-censored graft survival. Results. The majority of recipients 80 years and older was male (82.9%), white (87.9%), and less likely to have diabetes or coronary artery disease. More expanded criteria donor (ECD) but fewer living donor transplants were performed among 80 years and older compared with those younger than 80 years. Perioperative mortality, defined as death within 30 days posttransplant, was rare (60–69 years: 1.4%; 70–79 years: 1.5%; and ≥80 years: 2.5%) but tended to be higher among those 80 years and older compared with recipients 60 to 69 years (hazard ratio [HR] 1.67; 95% confidence interval [CI] 0.69–4.05). At 2 years, survival was lower for 80 years and older (73%; HR 2.42; 95% CI 1.91–3.06) and 70 to 79 years (86%; HR: 1.42; 95% CI: 1.34–1.51) compared with recipients 60 to 69 years (89%). There was a greater risk of graft loss among recipients 80 years and older compared with those 60 to 69 years (HR 1.78; 95% CI 1.42–2.23); however, no difference in death-censored graft survival was observed (0.89; 0.57–1.39). Among recipients 80 years and older, no difference in survival was observed between standard criteria donor and ECD recipients. Conclusion. Although perioperative mortality was uncommon among elderly recipients (1.5%), a trend toward higher perioperative mortality was observed in recipients 80 years and older. There was no difference in survival among standard criteria donor and ECD recipients.

DNA testing for live kidney donors at risk for autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by age-dependent growth of kidney cysts with end-stage renal disease developing in approximately 50% of affected individuals. Living donors from ADPKD families are at risk for developing ADPKD and may be excluded from renal donation if the diagnosis cannot be conclusively ruled out. Radiographic imaging may be adequate to screen for kidney cysts in most at-risk donors but may fail to identify affected individuals younger than 40 years or older individuals from families with mild disease. In this article, we report a strategy that incorporates genetic testing in the evaluation of live kidney donors at risk for ADPKD whose disease status cannot be established with certainty on the basis of imaging studies alone. We show that DNA diagnostics can be used to enhance safe donation for certain living donor candidates at risk for ADPKD.

Alemtuzumab Induction in Deceased Donor Kidney Transplantation

Background. The use of alemtuzumab for induction therapy in kidney transplantation has been increasing. Herein is a report of graft outcomes associated with alemtuzumab induction from the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Methods. A total of 14,362 deceased donor kidney transplants from 2003 to 2004 received no induction (n=4,364), antithymocyte globulin (ATG; n=4,930), interleukin-2 receptor antagonists (IL-2RA; n=4,378), or alemtuzumab (n=690). Acute rejection within the initial hospitalization, 6 months, and 1 year; graft survival; and rejection-free survival were examined. Graft and rejection-free survival of alemtuzumab recipients maintained with tacrolimus (FK) or cyclosporine (CSA), mycophenolate mofetil (MMF), and steroids versus no calcineurin inhibitors (CNI), MMF, and steroids were compared. Results. Alemtuzumab recipients had less acute rejection during the initial hospitalization (2.3%) than no induction, ATG, and IL-2RA (7.6%, 3.4%, and 4.8%, respectively; P<0.001). There was increased acute rejection at 6 months and 1 year with alemtuzumab (14.5% and 19.2%) compared to no induction (12.7% and 14.8%, P<0.001), ATG (8.2% and 10.2%, P<0.001), and IL-2RA (11.1% and 13.0%, P<0.001) with no difference in adjusted relative risk for graft loss. Alemtuzumab recipients receiving FK or CSA, MMF, and steroids had increased graft (FK/MMF/steroids, P<0.001, CSA/MMF/steroids, P=0.007) and rejection-free survival (FK/MMF/steroids, P<0.001, CSA/MMF/steroids, P=0.006) over 24 months compared to no CNI, MMF, and steroids. Conclusions. Despite reduced early rejection, acute rejection rates at 6 months and 1 year with alemtuzumab induction exceeded other forms of induction therapy. Maintenance with CNI-based immunosuppression may improve graft and rejection-free survival compared to CNI-free regimens among alemtuzumab recipients.

Association of Pretransplant Glycemic Control With Posttransplant Outcomes in Diabetic, Kidney-Transplant Recipients

OBJECTIVE Observational studies have yielded inconsistent findings regarding the association of hemoglobin A1c (HbA1c) with survival in diabetic patients on dialysis. The association between pretransplant glycemic control and short- and long-term posttransplant outcomes in kidney transplant recipients is not clear. RESEARCH DESIGN AND METHODS Linking the 5-year patient data of a large dialysis organization (DaVita) to the Scientific Registry of Transplant Recipients, we identified 2,872 diabetic dialysis patients who underwent first kidney transplantation. Mortality or graft failure and delayed graft function (DGF) risks were estimated by Cox regression (hazard ratio [HR]) and logistic regression (odds ratio), respectively. RESULTS Patients were 53 ± 11 years old and included 36% women and 24% African Americans. In our fully adjusted model, allograft failure–censored, all-cause death HR and 95% CI for time-averaged pretransplant HbA1c categories of 7 to <8%, 8 to <9%, 9 to 10%, and ≥10%, compared with 6 to <7% (reference), were 0.89 (0.59–1.36), 2.06 (1.31–3.24), 1.41 (0.73–2.74), and 3.43 (1.56–7.56), respectively; and graft failure–censored cardiovascular death HR was 0.38 (0.13–1.05), 1.78 (0.69–4.55), 1.59 (0.44–5.76), and 4.28 (0.85–21.64), respectively. We did not find any difference in risk of death-censored graft failure or DGF with different pretransplant HbA1c levels. CONCLUSIONS Poor pretransplant glycemic control appears associated with decreased posttransplant survival in kidney transplant recipients, whereas allograft outcomes may not be affected.

Outcomes of preemptive kidney with or without subsequent pancreas transplant compared with preemptive simultaneous pancreas/kidney transplantation.

Background. Prior studies have indicated that type 1 diabetic (T1DM) recipients of a simultaneous pancreas-kidney (SPK) transplant have greater short-term mortality compared with living donor kidney (LDK) transplantation. Whether this association remains and how outcomes compare to deceased donor kidney (DDK) transplantation in the preemptive setting are unknown. Methods. Using data on recipients transplanted between 2000 and 2010 from the Organ Procurement and Transplantation Network/United Network of Organ Sharing, patient and graft survival (calculated from the time of kidney transplant) of pancreas after preemptive LDK (PALK, n=389), preemptive LDK not receiving a pancreas transplant (LDK/noP, n=289), preemptive DDK (n=112), and preemptive SPK transplantations (n=1402) were compared. Results. At 6 years, patient survival was excellent (PALK=89.4%, LDK/noP=84.9%, DDK=81.2%, and SPK=91.1%) and not different between PALK, LDK/noP, and SPK (P value vs. PALK: LDK/noP=0.08; SPK=0.85) but was lower with preemptive DDK versus preemptive PALK (P=0.03). When both LDK groups were considered together, there was higher mortality in the first 180 days after transplant with preemptive DDK (3.7% vs. 1.1%; P=0.03) and similar mortality with preemptive SPK (2.3%; P=0.07). After multivariate adjustment, there was a trend toward increased risk of death with preemptive DDK compared with preemptive PALK (hazard ratio: 1.91; 95% confidence interval: 0.95–3.84). Conclusions. Patient survival associated with preemptive transplantation among T1DM recipients was excellent at 6 years, with the greatest survival favoring PALK, LDK/noP, and SPK rather than DDK. In contrast with prior studies reporting greater short-term mortality with SPK among the general T1DM population, short-term mortality after preemptive transplant is similar between LDK and SPK.

Incidence of Conversion to Active Waitlist Status Among Temporarily Inactive Obese Renal Transplant Candidates

Background Candidates may be active or temporarily inactive (status 7) on the kidney transplant waiting list. One reason candidates may be inactive is for a “weight currently inappropriate for transplantation.” We hypothesized that many of these candidates would not achieve active status. Methods Using OPTN/UNOS data from 2006 to 2012, we used competing risks methods to determine the cumulative incidence of conversion to active status (activation), death, and delisting before conversion among 1679 obese adult kidney candidates designated as status 7 because of a weight inappropriate for transplantation. Fine and Gray competing risks regression was performed to characterize factors associated with conversion to active status in the overall study population and of transplantation among a subgroup of activated candidates. Results At 6 years, the cumulative incidence of activation was 49%, of death before conversion was 15%, and of delisting was 21%. Higher body mass index (BMI) was strongly associated with a decreased subhazard of activation (BMI ≥45 versus 30–34.9, sHR: 0.22; 95% CI, 0.16–0.33). Female sex, diabetic end-stage renal disease, history of a previous transplant, panel reactive antibodies less than 80%, dialysis dependence at listing, and UNOS region 5 were negatively associated with activation. Among activated candidates, the cumulative incidence of transplantation at 6 years after initial waitlisting was 61%. Conclusion Our findings indicate that half of obese status 7 candidates with a weight inappropriate for transplantation will not achieve active waitlist status. BMI at listing had a strong association with conversion to active status; comorbid factors and regional variation also impact activation.