The Collaborative Innovation and Improvement Network (COIIN): Effect on donor yield, waitlist mortality, transplant rates, and offer acceptance.

The Organ Procurement and Transplantation Network implemented the Collaborative Improvement and Innovation Network (COIIN) to improve the use of donors with kidney donor profile index >50%. COIIN recruited 2 separate cohorts of kidney transplant programs. Cohort A included 19 programs of 44 applicants (January 1, 2017, to September 30, 2017), and cohort B included 39 programs of 47 applicants (October 1, 2017, to June 30, 2018). We investigated the effect of COIIN on kidney yield (number of kidneys transplanted from donors from whom any organ was recovered), offer acceptance, deceased donor transplant rates, and waitlist mortality rates for January 1, 2016, to March 31, 2019. COIIN did not notably affect kidney yield or waitlist mortality rates. Cohort A, but not cohort B, had significantly higher deceased donor transplant and offer acceptance rates during its intervention period than programs not in COIIN (adjusted transplant rate ratio: cohort A, 1.08 1.171.27 , cohort B, 0.94 1.011.08 ; adjusted offer acceptance ratio: cohort A, 1.08 1.181.29 , cohort B, 0.93 1.001.08 ). Thus, COIIN improved the use of kidneys at programs in cohort A but not at those in cohort B. Further research is necessary to understand the different effects for cohorts A and B, and further monitoring of posttransplant outcomes is required.

The association between loss of Medicare, immunosuppressive medication use, and kidney transplant outcomes.

Kidney transplant recipients aged <65 years qualify for Medicare coverage, but coverage ends 3 years posttransplant. We determined the association between timing of Medicare loss and immunosuppressive medication fills and kidney allograft loss. Using data from the Scientific Registry of Transplant Recipients (SRTR), US Renal Data System, and Symphony pharmacy fill database, we analyzed 78 861 Medicare-covered, kidney-alone recipients aged <65 years, and assessed the timing of Medicare loss posttransplant: early (<3 years), on-time (at 3 years), or late (>3 years). Immunosuppressant use was measured as medication possession ratio (MPR). Allograft loss was assessed using SRTR data. MPR was lower for recipients with early or late Medicare loss compared with no coverage loss for all immunosuppressive medication types. For calcineurin inhibitors, early Medicare loss was associated with a 53% to 86% lower MPR. On-time Medicare loss was not associated with a lower MPR. When recipients were matched by age, posttransplant timing of Medicare loss, and donor risk, the hazard of allograft loss was 990% to 1630% higher after early Medicare loss, and 140% to 740% higher after late Medicare loss, with no difference in the hazard for on-time Medicare loss. Ensuring ongoing Medicare access before and after 3 years posttransplant could affect graft survival.

Association of pretransplant and posttransplant program ratings with candidate mortality after listing.

The Scientific Registry of Transplant Recipients (SRTR) is responsible for understandable reporting of program metrics, including transplant rate, waitlist mortality, and posttransplant outcomes. SRTR developed five-tier systems for each metric to improve accessibility for the public. We investigated the associations of the five-tier assignments at listing with all-cause candidate mortality after listing, for candidates listed July 12, 2011-June 16, 2014. Transplant rate evaluations with one additional tier were associated with lower mortality after listing in kidney (hazard ratio [HR], 0.93 0.950.97 ), liver (HR, 0.87 0.900.92 ), and heart (HR, 0.92 0.961.00 ) transplantation. For lung transplant patients, mortality after listing was highest at programs with above- and below-average transplant rates and lowest at programs with average transplant rates, suggesting that aggressive acceptance behavior may not always provide a survival benefit. Waitlist mortality evaluations with one additional tier were associated with lower mortality after listing in kidney (HR, 0.94 0.960.99 ) transplantation, and posttransplant graft survival evaluations with one additional tier were associated with lower mortality after listing in lung (HR, 0.90 0.940.98 ) transplantation. Transplant rate typically had the strongest association with mortality after listing, but the strength of associations differed by organ.

Comparing Scientific Registry of Transplant Recipients posttransplant program-specific outcome ratings at listing with subsequent recipient outcomes after transplant.

To improve accessibility of program-specific reports to patients, the Scientific Registry of Transplant Recipients released a 5-tier system for categorizing 1-year posttransplant program evaluations. Whether this system predicts subsequent posttransplant outcomes at the time patients are waitlisted has been questioned. We investigated the association of tier at listing and the corresponding continuous score used for tier assignment, which ranges from 0 (poor outcomes) to 1 (good outcomes), with eventual 1-year posttransplant graft survival for candidates listed between July 12, 2011, and June 16, 2014, who underwent transplant before December 31, 2016. One additional tier at listing was associated with better 1-year posttransplant outcomes in liver (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.89-0.97) and lung transplant (HR, 0.90; 95% CI, 0.84-0.97) but not kidney (HR, 0.96; 95% CI, 0.92-1.01) or heart transplant (HR, 1.02; 95% CI, 0.93-1.10). In liver and lung transplant, longer time between listing and transplant was associated with stronger protective effects for high-tier programs. In kidney, liver, and lung transplant, posttransplant evaluations at listing had nonlinear associations with eventual posttransplant outcomes: relatively flat for 5-tier scores <0.5 and decreasing for scores >0.5. After adjustment for measured recipient and donor risk factors, posttransplant evaluations at listing predicted differences in eventual outcomes in liver and lung transplant, providing useful information to patients.

The relationship between the C-statistic and the accuracy of program-specific evaluations.

The C-statistic of the risk-adjustment model is often used to judge the accuracy of program evaluations. However, the C-statistic depends on the variability in risk for individual transplants and may be inappropriate for determining the accuracy of program evaluations. A simulation study investigated the association of the C-statistic with several metrics of program evaluation accuracy, including categorizing programs into the 5-tier system and identifying programs for regulatory review. The simulation study used data from deceased donor kidney-alone transplants for adult recipients in the program-specific reports released January 2018. A range of C-statistics was generated by changing the variability in risk for individual transplants. The C-statistic had no association with any metric of program evaluation accuracy. Instead, the number of expected events at a program was the most important factor. For example, Spearman's rho, which is the correlation of ranks, was -0.27 and -0.72 between the true program-specific hazard ratios and assigned tiers for programs with, respectively, <3 and >10 expected events. Presence of unadjusted risk factors did not modify the associations, although the accuracy of program evaluations was systematically lower. Therefore, the C-statistic provides no information on the accuracy of program evaluations.

Therapeutic Effect of Blueberry Extracts for Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is an aggressive hematological malignancy with high incidence in the aging population. In addition, AML is one of the more common pediatric malignancies. Unfortunately, both of these patient groups are quite sensitive to chemotherapy toxicities. Investigation of blueberries specifically as an anti-AML agent has been limited, despite being a prominent natural product with no reported toxicity. In this study, blueberry extracts are reported for the first time to exert a dietary therapeutic effect in animal models of AML. Furthermore, in vitro studies revealed that blueberry extracts exerted anti-AML efficacy against myeloid leukemia cell lines as well as against primary AML, and specifically provoked Erk and Akt regulation within the leukemia stem cell subpopulation. This study provides evidence that blueberries may be unique sources for anti-AML biopharmaceutical compound discovery, further warranting fractionation of this natural product. More so, blueberries themselves may provide an intriguing dietary option to enhance the anti-AML efficacy of traditional therapy for subsets of patients that otherwise may not tolerate rigorous combinations of therapeutics.

Combinatorial Efficacy of Quercitin and Nanoliposomal Ceramide for Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is an aggressive hematological malignancy with limited treatment options. Inflammation is often a contributing factor to the development and progression of AML, and related diseases, and can potentiate therapy failure. Previously, we had identified anti-inflammatory roles and anti-AML efficacy for blueberry extracts. The present study extended these observations to determine that the polyphenol quercetin inhibited neutral sphingomyelinase (N-SMase) activity and exerted anti-AML efficacy. Moreover, quercetin was shown to exert combinatorial anti-AML efficacy with nanoliposomal ceramide. Overall, this demonstrated that quercetin could block the pro-inflammatory actions of N-SMase and augment the efficacy of anti-AML therapeutics, including ceramide-based therapeutics.

Risk of Second Malignancies in Solid Organ Transplant Recipients Who Develop Keratinocyte Cancers.

Solid organ transplant recipients have increased risk for developing keratinocyte cancers, including cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), in part as a result of immunosuppressive medications administered to prevent graft rejection. In the general population, keratinocyte cancers are associated with increased risks of subsequent malignancy, however, the risk in organ transplant populations has not been evaluated. We addressed this question by linking the U.S. Scientific Registry of Transplant Recipients, which includes data on keratinocyte cancer occurrence, with 15 state cancer registries. Risk of developing malignancies after keratinocyte cancer was assessed among 118,440 Caucasian solid organ transplant recipients using multivariate Cox regression models. Cutaneous SCC occurrence (n = 6,169) was associated with 1.44-fold increased risk [95% confidence interval (CI), 1.31-1.59] for developing later malignancies. Risks were particularly elevated for non-cutaneous SCC, including those of the oral cavity/pharynx (HR, 5.60; 95% CI, 4.18-7.50) and lung (HR, 1.66; 95% CI, 1.16-2.31). Cutaneous SCC was also associated with increased risk of human papillomavirus-related cancers, including anal cancer (HR, 2.77; 95% CI, 1.29-5.96) and female genital cancers (HR, 3.43; 95% CI, 1.44-8.19). In contrast, BCC (n = 3,669) was not associated with overall risk of later malignancy (HR, 0.98; 95% CI, 0.87-1.12), including any SCC. Our results suggest that transplant recipients with cutaneous SCC, but not BCC, have an increased risk of developing other SCC. These findings somewhat differ from those for the general population and suggest a shared etiology for cutaneous SCC and other SCC in the setting of immunosuppression. Cutaneous SCC occurrence after transplantation could serve as a marker for elevated malignancy risk. Cancer Res; 77(15); 4196-203. ©2017 AACR.

Access to Kidney Transplantation among HIV-Infected Waitlist Candidates.

BACKGROUND AND OBJECTIVES: Kidney transplantation among HIV-infected patients with ESRD confers a significant survival benefit over remaining on dialysis. Given the high mortality burden associated with dialysis, understanding access to kidney transplantation after waitlisting among HIV+ candidates is warranted. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data from the Scientific Registry of Transplant Recipients were linked to Intercontinental Marketing Statistics pharmacy fills (January 1, 2001 to October 1, 2012) so that we could identify and study 1636 HIV+ (defined as having filled one or more antiretroviral medications unique to HIV treatment) and 72,297 HIV- kidney transplantation candidates. RESULTS: HIV+ waiting list candidates were more often young (<50 years old: 62.7% versus 37.6%; P<0.001), were more often men (75.2% versus 59.3%; P<0.001), were more often black (73.6% versus 27.9%; P<0.001), had longer time on dialysis (years: 2.5 versus 0.8; P<0.001), were more often coinfected with hepatitis C virus (9.0% versus 3.9%; P<0.001), and were less likely to remain active on the waiting list (37.7% versus 49.4%; P<0.001). Waitlist mortality among HIV+ candidates was similar compared with HIV- candidates (adjusted hazard ratio, 1.03; 95% confidence interval, 0.89 to 1.20; P=0.67). In contrast, likelihood of living donor kidney transplantation was 47% lower (adjusted hazard ratio, 0.53; 95% confidence interval, 0.44 to 0.64; P<0.001), and there was a trend toward lower likelihood of deceased donor kidney transplantation (adjusted hazard ratio, 0.87; 95% confidence interval, 0.74 to 1.01; P=0.07) compared with in HIV- candidates. CONCLUSIONS: Our findings highlight the need for additional study to better understand disparities in access to kidney transplantation, particularly living donor kidney transplantation, among HIV+ kidney waitlist candidates.

Survival Benefit of Kidney Transplantation in HIV-infected Patients.

OBJECTIVE: To determine the survival benefit of kidney transplantation in human immunodeficiency virus (HIV)-infected patients with end-stage renal disease (ESRD). SUMMARY BACKGROUND DATA: Although kidney transplantation (KT) has emerged as a viable option for select HIV-infected patients, concerns have been raised that risks of KT in HIV-infected patients are higher than those in their HIV-negative counterparts. Despite these increased risks, KT may provide survival benefit for the HIV-infected patient with ESRD, yet this important clinical question remains unanswered. METHODS: Data from the Scientific Registry of Transplant Recipients were linked to IMS pharmacy fills (January 1, 2001 to October 1, 2012) to identify and study 1431 HIV-infected KT candidates from the first point of active status on the waiting list. Time-dependent Cox regression was used to establish a counterfactual framework for estimating survival benefit of KT. RESULTS: Adjusted relative risk (aRR) of mortality at 5 years was 79% lower after KT compared with dialysis (aRR 0.21; 95% CI 0.10-0.42; P <0.001), and statistically significant survival benefit was achieved by 194 days of KT. Among patients coinfected with hepatitis C, aRR of mortality at 5 years was 91% lower after KT compared with dialysis (aRR 0.09; 95% CI 0.02-0.46; P < 0.004); however, statistically significant survival benefit was not achieved until 392 days after KT. CONCLUSIONS: Evidence suggests that for HIV-infected ESRD patients, KT is associated with a significant survival benefit compared with remaining on dialysis.

Allocating Deceased Donor Kidneys to Candidates with High Panel-Reactive Antibodies.

BACKGROUND AND OBJECTIVES: In December of 2014, the Organ Procurement and Transplant Network implemented a new Kidney Allocation System (KAS) for deceased donor transplant, with increased priority for highly sensitized candidates (calculated panel-reactive antibody [cPRA] >99%). We used a modified version of the new KAS to address issues of access and equity for these candidates. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a simulation, 10,988 deceased donor kidneys transplanted into waitlisted recipients in 2010 were instead allocated to candidates with cPRA≥80% (n=18,004). Each candidate's unacceptable donor HLA antigens had been entered into the allocation system by the transplant center. In simulated match runs, kidneys were allocated sequentially to adult ABO identical or permissible candidates with cPRA 100%, 99%, 98%, etc. to 80%. Allocations were restricted to donor/recipient pairs with negative virtual crossmatches. RESULTS: The simulation indicated that 2111 of 10,988 kidneys (19.2%) would have been allocated to patients with cPRA 100% versus 74 of 10,988 (0.7%) that were actually transplanted. Of cPRA 100% candidates, 74% were predicted to be compatible with an average of six deceased donors; the remaining 26% seemed to be incompatible with every deceased donor organ that entered the system. Of kidneys actually allocated to cPRA 100% candidates in 2010, 66% (49 of 74) were six-antigen HLA matched/zero-antigen mismatched (HLA-A, -B, and -DR) with their recipients versus only 11% (237 of 2111) in the simulation. The simulation predicted that 10,356 of 14,433 (72%) candidates with cPRA 90%-100% could be allocated an organ compared with 7.3% who actually underwent transplant. CONCLUSIONS: Data in this simulation are consistent with early results of the new KAS; specifically, nearly 20% of deceased donor kidneys were (virtually) compatible with cPRA 100% candidates. Although most of these candidates were predicted to be compatible with multiple donors, approximately one-quarter are unlikely to receive a single offer.

Cost Implications of New National Allocation Policy for Deceased Donor Kidneys in the United States.

BACKGROUND: In December 2014, a new national deceased donor kidney allocation policy was implemented, which allocates kidneys in the top 20% of the kidney donor profile index to candidates in the top 20% of expected survival. We examined the cost implications of this policy change. METHODS: A Markov model was applied to estimate differences in total lifetime cost of care and quality-adjusted life years (QALY). RESULTS: Under the old allocation policy, average lifetime outcomes per listed patient discounted to 2012 US dollars were US $342,799 and 5.42 QALY, yielding US $63,775 per QALY gained. Under the new policy, average lifetime cost was reduced by US $2090 and lifetime QALYs increased by 0.03. Thus, the new policy improved on the old policy by producing more QALYs at lower cost. The present value of total lifetime cost savings from the policy change is estimated to be US $271 million in the first year and US $55 million in subsequent years. The higher transplant rates and allograft survival expected for candidates in the top 20% of expected survival would decrease costs by reducing time on dialysis. Most cost savings are expected to accrue to Medicare, and most increased access to transplant is expected in private payer populations. CONCLUSIONS: The new allocation policy was found to be dominant over the old policy because it increases QALYs at lower cost.

Effects of maintenance immunosuppression with sirolimus after liver transplant for hepatocellular carcinoma.

For recipients of liver transplantations (LTs) for hepatocellular carcinoma (HCC), HCC recurrence after transplantation remains a major concern. Sirolimus (SRL), an immunosuppressant with anticarcinogenic properties, may reduce HCC recurrence and improve survival. In our study, the US Scientific Registry of Transplant Recipients was linked to pharmacy claims. For liver recipients transplanted for HCC, Cox regression was used to estimate associations of early SRL use with recurrence, cancer-specific mortality, and all-cause mortality, adjusting for recipient ethnicity, calendar year of transplant, total tumor volume, alpha-fetoprotein, transplant center size, use of interleukin 2 induction therapy, and allocated and calculated Model for End-Stage Liver Disease score. We performed stratified analyses among recipients who met Milan criteria, among those without renal failure, among those with deceased liver donors, by age at transplantation, and by tumor size. Among the 3936 included HCC LTs, 234 (6%) were SRL users. In total, there were 242 recurrences and 879 deaths, including 261 cancer-related deaths. All-cause mortality was similar in SRL users and nonusers (adjusted hazard ratio [aHR], 1.01; 95% CI, 0.73-1.39). HCC recurrence and cancer-specific mortality rates appeared lower in SRL users, but associations were not statistically significant (recurrence aHR, 0.86; 95% CI, 0.45-1.65; cancer-specific mortality aHR, 0.80; 95% CI, 0.43-1.50). Among recipients >55 years old, associations were suggestive of better outcomes for SRL users (all-cause mortality aHR, 0.62; 95% CI, 0.38-1.01; recurrence aHR, 0.52; 95% CI, 0.19-1.44; cancer-specific mortality aHR, 0.34; 95% CI, 0.11-1.09), whereas among recipients ≤55 years old, SRL users had worse outcomes (all-cause mortality aHR, 1.76; 95% CI, 1.12-2.75; recurrence aHR, 1.49; 95% CI, 0.62-3.61; cancer-specific mortality aHR, 1.54; 95% CI, 0.71-3.32). In conclusion, among HCC liver recipients overall, SRL did not appear beneficial in reducing all-cause mortality. However, there were suggestions of reductions in recurrence and cancer-specific mortality, and effects appeared to be modified by age at transplantation. Liver Transplantation 22 627-634 2016 AASLD.

Controlling confounding of treatment effects in administrative data in the presence of time-varying baseline confounders.

PURPOSE: Confounding, a concern in nonexperimental research using administrative claims, is nearly ubiquitous in claims-based pharmacoepidemiology studies. A fixed-length look-back window for assessing comorbidity from claims is common, but it may be advantageous to use all historical claims. We assessed how the strength of association between a baseline-identified condition and subsequent mortality varied by when the condition was measured and investigated methods to control for confounding. METHODS: For Medicare beneficiaries undergoing maintenance hemodialysis on 1 January 2008 (n = 222 343), we searched all Medicare claims, 1 January 2001 to 31 December 2007, for four conditions representing chronic and acute diseases, and classified claims by number of months preceding the index date. We used proportional hazard models to estimate the association between time of condition and subsequent mortality. We simulated a confounded comorbidity-exposure relationship and investigated an alternative method of adjustment when the association between the condition and mortality varied by proximity to follow-up start. RESULTS: The magnitude of the mortality hazard ratio estimates for each condition investigated decreased toward unity as time increased between index date and most recent manifestation of the condition. Simulation showed more biased estimates of exposure-outcome associations if proximity to follow-up start was not considered. CONCLUSIONS: Using all-available claims information during a baseline period, we found that for all conditions investigated, the association between a comorbid condition and subsequent mortality varied considerably depending on when the condition was measured. Improved confounding control may be achieved by considering the timing of claims relative to follow-up start.

Impact of increased time at the highest urgency category on heart transplant outcomes for candidates with ventricular assist devices.

BACKGROUND: Ventricular assist devices (VADs) have improved survival among end-stage heart disease patients. Since 2002, heart transplant candidates with VADs have been afforded 30 days of elective time at the highest urgency category (Status 1A) under Organ Procurement and Transplantation Network (OPTN) policy. We aimed to determine the effect of increasing elective time at the highest urgency category for heart transplant candidates with VADs. This analysis was requested by OPTN during its evaluation of heart allocation policy. METHODS: We simulated several allocation schemes wherein elective Status 1A time was increased to 45, 60, and 90 days; results were compared with a baseline simulation of 30 days and with the actual observed heart transplant waiting list cohort. RESULTS: The simulations showed that increasing elective Status 1A time for candidates with VADs did not substantially change waiting list mortality overall or for sub-groups of concern, which were candidates with VADs listed at a lower-urgency category (Status 1B), those with with VAD complications, total artificial heart, or intraaortic balloon pump support; or those with extracorporeal membrane oxygenation. Across the different time allowances, the average post-transplant death rate remained stable. It also remained stable for recipients previously listed as Status 1A or 1B categories for VAD and for recipients with VAD complications or an intraaortic balloon pump at transplant, on extracorporeal membrane oxygenation, and those without devices. CONCLUSIONS: Our results suggest that increasing time in the highest urgency category for candidates with VADs would not improve waiting list mortality or post-transplant outcomes for heart transplant candidates overall.

Conditioning causes an increase in glucose transporter-4 levels in mononuclear cells in sled dogs.

This study was designed to investigate the effects of physical conditioning on the expression of the insulin sensitive glucose transporter-4 protein (GLUT4) on mononuclear cells and HOMA-IR levels in dogs and compared to results reported in human skeletal muscle and the skeletal muscle of rodent models. Blood was sampled from conditioned dogs (n = 8) and sedentary dogs (n = 8). The conditioned dogs were exercised four months prior the experiment and were following a uniform training protocol, whereas the sedentary dogs were not. GLUT4 expression in mononuclear cells and plasma insulin levels were measured using commercially available enzyme-linked immunosorbent assay (ELISA). Blood glucose levels were determined using blood plasma. HOMA-IR was calculated using plasma insulin and blood glucose levels using the linear approximation formula. Our results indicate that the state of conditioning had a significant effect on the GLUT4 expression at the surface of mononuclear cells. HOMA-IR was also affected by conditioning in dogs. GLUT4 levels in mononuclear cells of sled dogs were inversely correlated with the homeostasis model assessment of insulin sensitivity. This study demonstrates that conditioning increases GLUT4 levels in mononuclear cells of sled dogs as it has been previously reported in skeletal muscle. Our results support the potential of white blood cells as a proxy tissue for studying insulin signaling and may lead to development of a minimally invasive and direct marker of insulin resistance. This may be the first report of GLUT4 in mononuclear cells in response to exercise and measured with ELISA.

New national allocation policy for deceased donor kidneys in the United States and possible effect on patient outcomes.

In 2013, the Organ Procurement and Transplantation Network in the United States approved a new national deceased donor kidney allocation policy that introduces the kidney donor profile index (KDPI), which gives scores of 0%-100% based on 10 donor factors. Kidneys with lower KDPI scores are associated with better post-transplant survival. Important features of the new policy include first allocating kidneys from donors with a KDPI≤20% to candidates in the top 20th percentile of estimated post-transplant survival, adding waiting time from dialysis initiation, conferring priority points for a calculated panel-reactive antibody (CPRA)>19%, broader sharing of kidneys for candidates with a CPRA≥99%, broader sharing of kidneys from donors with a KDPI>85%, eliminating the payback system, and allocating blood type A2 and A2B kidneys to blood type B candidates. We simulated the distribution of kidneys under the new policy compared with the current allocation policy. The simulation showed increases in projected median allograft years of life with the new policy (9.07 years) compared with the current policy (8.82 years). With the new policy, candidates with a CPRA>20%, with blood type B, and aged 18-49 years were more likely to undergo transplant, but transplants declined in candidates aged 50-64 years (4.1% decline) and ≥65 years (2.7% decline). These simulations demonstrate that the new deceased donor kidney allocation policy may improve overall post-transplant survival and access for highly sensitized candidates, with minimal effects on access to transplant by race/ethnicity and declines in kidney allocation for candidates aged ≥50 years.

Phytochemical changes in phenolics, anthocyanins, ascorbic acid, and carotenoids associated with sweetpotato storage and impacts on bioactive properties.

Sweetpotato phytochemical content was evaluated in four genotypes (NCPUR06-020, Covington, Yellow Covington, and NC07-847) at harvest and after curing/storage for 4 or 8 months. Curing and storage for up to 8 months did not significantly affect total phenolic content in Covington, Yellow Covington, and NC07-847, however for NCPUR06-020, a purple-fleshed selection, total phenolic content declined mainly due to anthocyanin degradation during storage. Covington had the highest carotenoid content at harvest time (281.9 µg/g DM), followed by NC07-847 (26.2 µg/g DM), and after 8 months, total carotenoids had increased by 25% and 50%, respectively. Antioxidant activity gradually declined during storage, and freshly harvested sweetpotatoes also demonstrated higher anti-inflammatory capacity as gauged by inhibition of lipopolysaccharide-induced reactive oxygen species (ROS) in SH-SY5Y cells. Gradual changes in sweetpotato phytochemical content and antioxidant and anti-inflammatory capacity were noted during normal long-term storage, but the specific effects were genotype-dependent.

Metformin use in kidney transplant recipients in the United States: an observational study.

BACKGROUND/AIMS: Although metformin is contraindicated in patients with increased serum creatinine levels (≥1.5 mg/dl in men, ≥1.4 mg/dl in women) in the United States, its use has not been systematically examined in kidney transplant recipients. We aimed to determine the frequency of metformin use and its associations among kidney transplant recipients, and to assess allograft and patient survival associated with metformin use. METHODS: In this retrospective cohort study, we linked Scientific Registry of Transplant Recipients data for all incident kidney transplants 2001-2012 and national pharmacy claims (n = 46,914). We compared recipients having one or more pharmacy claims for a metformin-containing product (n = 4,609) and recipients having one or more claims for a non-metformin glucose-lowering agent (n = 42,305). RESULTS: On average, metformin claims were filled later after transplant and were associated with higher estimated glomerular filtration rates before the first claim. Median serum creatinine (mg/dl) levels before the first claim were lower in recipients with metformin claims than in those with non-metformin claims (1.3 [interquartile range 1.0-1.7] vs. 1.6 [1.2-2.5], respectively; p < 0.0001). Metformin was associated with lower adjusted hazards for living donor (0.55, 95% confidence interval 0.38-0.80; p = 0.002) and deceased donor (0.55, 0.44-0.70; p < 0.0001) allograft survival at 3 years posttransplant, and with lower mortality. CONCLUSIONS: Despite metformin being contraindicated in renal dysfunction, many kidney transplant recipients receive it, and it is not associated with worse patient or allograft survival.