Organ donation and utilization in the USA

The processes leading to donor identification, consent, organ procurement, and allocation continue to dominate debates and efforts in the field of transplantation. A considerable shortage of donors remains while the number of patients needing organ transplantation increases.
This article reviews the main trends in organ donation practices and procurement patterns from both deceased and living sources in the USA. Although there have been increases in living donation in recent years, 2002 witnessed a much more modest growth of 1%. Absolute declines in living liver and lung donation were also noted in 2002.
In 2002, the number of deceased donors increased by only 1.6% (101 donors). Increased donation from deceased donors provides more organs for transplantation than a comparable increase in living donation, because on average 3.6 organs are recovered from each deceased donor. The total number of organs recovered from deceased donors increased by 2.1% (462 organs). Poor organ quality continued to be the major reason given for nonrecovery of consented organs from deceased donors.
The kidney is the organ most likely to be discarded after recovery. Over the past decade the discard rate of recovered kidneys has increased from 6% to 11%. Many of these are expanded criteria donor kidneys.     

The use of expanded criteria donor organs for transplantation

Expanded criteria donors (ECD) of kidneys include all those aged ≥60 years and donors aged 50–59 years with at least 2 of the following 3 medical criteria: (1) cerebrovascular accident as the cause of death, (2) terminal serum creatinine concentration >1.5 mg/dL, and (3) history of systemic hypertension. ECD kidneys now account for 20% of all deceased donor kidneys in the United States, with the fraction being as high as 35% in some donation service areas. However, procured ECD kidneys continue to be discarded at a significantly higher rate (41%) compared with 8% for non-ECD kidneys. Patients who elect to be offered and receive ECD kidneys have survival benefits of decreased long-term mortality between 17% and 27% when compared to waiting longer and subsequently receiving an standard criteria donors organ, but only if the waiting time is more than 44 months. The experience with ECD kidneys in the United States suggests that organ donation and transplantation rates can be significantly improved through the systematic incorporation of ECD policies into organ procurement and transplantation schemes. More refined definition of ECD and rigorous assessment of the outcomes of ECD organ transplantation will further contribute to improving the use of all donated organs.     

Chronic Renal Insufficiency Cohort Study (CRIC): Overview and Summary of Selected Findings

The Chronic Renal Insufficiency Cohort (CRIC) Study is a United States multicenter, prospective study of racially and ethnically diverse patients with CKD. Although the original aims of the study were to identify novel predictors of CKD progression and to elucidate the risk and manifestations of cardiovascular disease among nearly 4000 individuals with CKD, the CRIC Study has evolved into a national resource for investigation of a broad spectrum of CKD-related topics. The study has produced >90 published scientific articles, promoted many young investigative careers in nephrology, and fostered international collaborations focused on understanding the global burden of CKD. The third phase of the CRIC Study will complete enrollment of 1500 additional study participants in 2015 and is designed to answer questions regarding morbidity and mortality in mild-to-moderate CKD and to assess the burden of CKD in older persons. This review highlights some of the salient findings of the CRIC Study in the areas of race and ethnicity, CKD progression, CKD and cognition, and cardiovascular disease outcomes; it also outlines the ongoing and forthcoming opportunities for the global nephrology community to enhance its understanding of CKD and related complications through the study.     

Chronic Kidney Disease and Cognitive Function in Older Adults: Findings from the Chronic Renal Insufficiency Cohort Cognitive Study

OBJECTIVES: To investigate cognitive impairment in older, ethnically diverse individuals with a broad range of kidney function, to evaluate a spectrum of cognitive domains, and to determine whether the relationship between chronic kidney disease (CKD) and cognitive function is independent of demographic and clinical factors. DESIGN: Cross‐sectional. SETTING: Chronic Renal Insufficiency Cohort Study. PARTICIPANTS: Eight hundred twenty‐five adults aged 55 and older with CKD. MEASUREMENTS: Estimated glomerular filtration rate (eGFR, mL/min per 1.73 m²) was estimated using the four‐variable Modification of Diet in Renal Disease equation. Cognitive scores on six cognitive tests were compared across eGFR strata using linear regression; multivariable logistic regression was used to examine level of CKD and clinically significant cognitive impairment (score ≤1 standard deviations from the mean). RESULTS: Mean age of the participants was 64.9, 50.4% were male, and 44.5% were black. After multivariable adjustment, participants with lower eGFR had lower cognitive scores on most cognitive domains (P<.05). In addition, participants with advanced CKD (eGFR<30) were more likely to have clinically significant cognitive impairment on global cognition (adjusted odds ratio (AOR) 2.0, 95% CI=1.1–3.9), naming (AOR=1.9, 95% CI=1.0–3.3), attention (AOR=2.4, 95% CI=1.3–4.5), executive function (AOR=2.5, 95% CI=1.9–4.4), and delayed memory (AOR=1.5, 95% CI=0.9–2.6) but not on category fluency (AOR=1.1, 95% CI=0.6–2.0) than those with mild to moderate CKD (eGFR 45–59). CONCLUSION: In older adults with CKD, lower level of kidney function was associated with lower cognitive function on most domains. These results suggest that older patients with advanced CKD should be screened for cognitive impairment.     

Metabolic syndrome and new onset diabetes after transplantation in kidney transplant recipients

Luan FL, Langewisch E, Ojo A. Metabolic syndrome and new onset diabetes after transplantation in kidney transplant recipients.
Clin Transplant 2010: 24: 778–783. © 2009 John Wiley & Sons A/S. Abstract: Background: Metabolic syndrome (MS) and new onset diabetes after transplant (NODAT) are common in kidney transplant patients. We studied the relationship between the two conditions and their impact on metabolic and cardiovascular risk profiles. Methods: All non‐diabetic patients transplanted between 1999 and 2005 who were followed up to 2006 were included. MS and NODAT were determined. Kaplan–Meier survival and various regression analyses were performed to determine the clinical correlates for both conditions and their association with various cardiovascular risk factors. Results: Among 591 patients, 314 (53.1%) had MS and 90 (15.2%) developed NODAT. The two conditions were highly associated with each other as 84 patients with NODAT also had MS (14.2%). Elevated body mass index and fasting glucose levels at transplant were risk factors for both conditions, whereas weight gain after transplant was associated only with MS. African American, old age, and hypertension‐related ESRD were risk factors for NODAT. Finally, the presence of MS was associated with reduced kidney function and elevated uric acid levels, whereas the presence of NODAT with elevated pulse pressure. Conclusions: MS and NODAT are highly prevalent and significantly associated with impaired metabolic and cardiovascular risk profiles. Early identification of such conditions may facilitate targeted therapeutic intervention.     

Impact of simultaneous pancreas and kidney transplantation on cardiovascular risk factors in patients with type 1 diabetes mellitus

We retrospectively investigated the impact of pancreas transplantation on cardiovascular disease risk factors in patients with type 1 diabetic end-stage renal disease (ESRD). Two cohorts of patients, 44 simultaneous pancreas and kidney transplant patients (SPK) and 30 kidney transplant-alone patients (KTA), were included. Univariate and multivariate analyses were performed. Compared with KTA patients, SPK patients had significantly lower mean arterial pressure (88.5+/-12.7 vs. 98.2+/-13.0 mmHg, P=0.002), lower pulse pressure (51.6+/-15.1 vs. 61.4+/-15.6 mmHg, P=0.008), lower low-density lipoprotein cholesterol (83.5+/-20.6 vs. 99.2+/-32.5 mg/dl, P=0.02), and required fewer lipid-lowering medications (31.8% vs. 60.0%, P=0.02). Compared with pretransplant values, only SPK patients showed significant improvement in both blood pressure and total cholesterol. We conclude that SPK significantly improves blood pressure and dyslipidemia compared with KTA in type 1 diabetic ESRD patients.     

Evaluation of pancreatic allograft dysfunction by laparoscopic biopsy

BACKGROUND: Histologic evaluation of a failing pancreatic allograft is necessary for accurate classification of graft dysfunction. Unlike percutaneous or transcystoscopic techniques, laparoscopic biopsy allows visualization of the allograft in addition to obtaining tissue for histologic examination. METHODS: We retrospectively reviewed all laparoscopic pancreas transplant biopsies performed over a 15-month period ending February 2002. RESULTS: There were 12 laparoscopic pancreas biopsies performed in 11 patients between 6 weeks and 8 years (mean 2.5+/-2.8 years) after transplant. Indications for biopsy were hyperglycemia (n=8), hyperamylasemia (n=3), and graft tenderness (n=1). Adequate tissue was obtained in 11 of 12 biopsies. Two patients received definitive treatment at the time of laparoscopy (pseudocyst debridement, ovarian cyst excision). CONCLUSIONS: Laparoscopic pancreas transplant biopsy allows safe visualization of the allograft and effective specimen retrieval, and in some cases provides the opportunity for therapeutic intervention.     

Deceased-donor characteristics and the survival benefit of kidney transplantation

Context  Transplantation using kidneys from deceased donors who meet the expanded criteria donor (ECD) definition (age 60 years or 50 to 59 years with at least 2 of the following: history of hypertension, serum creatinine level >1.5 mg/dL [132.6 µmol/L], and cerebrovascular cause of death) is associated with 70% higher risk of graft failure compared with non-ECD transplants. However, if ECD transplants offer improved overall patient survival, inferior graft outcome may represent an acceptable trade-off. Objective  To compare mortality after ECD kidney transplantation vs that in a combined standard-therapy group of non-ECD recipients and those still receiving dialysis. Design, Setting, and Patients  Retrospective cohort study using data from a US national registry of mortality and graft outcomes among kidney transplant candidates and recipients. The cohort included 109 127 patients receiving dialysis and added to the kidney waiting list between January 1, 1995, and December 31, 2002, and followed up through July 31, 2004. Main Outcome Measure  Long-term (3-year) relative risk of mortality for ECD kidney recipients vs those receiving standard therapy, estimated using time-dependent Cox regression models. Results  By end of follow-up, 7790 ECD kidney transplants were performed. Because of excess ECD recipient mortality in the perioperative period, cumulative survival did not equal that of standard-therapy patients until 3.5 years posttransplantation. Long-term relative mortality risk was 17% lower for ECD recipients (relative risk, 0.83; 95% confidence interval, 0.77-0.90; P<.001). Subgroups with significant ECD survival benefit included patients older than 40 years, both sexes, non-Hispanics, all races, unsensitized patients, and those with diabetes or hypertension. In organ procurement organizations (OPOs) with long median waiting times (>1350 days), ECD recipients had a 27% lower risk of death (relative risk, 0.73; 95% confidence interval, 0.64-0.83; P<.001). In areas with shorter waiting times, only recipients with diabetes demonstrated an ECD survival benefit. Conclusions  ECD kidney transplants should be offered principally to candidates older than 40 years in OPOs with long waiting times. In OPOs with shorter waiting times, in which non-ECD kidney transplant availability is higher, candidates should be counseled that ECD survival benefit is observed only for patients with diabetes.