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1.
Bioorg Med Chem Lett ; 104: 129740, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38599294

RESUMEN

Leukocyte antigen-related (LAR) phosphatase is a receptor-type protein tyrosine phosphatase involved in cellular signaling and associated with human disease including cancer and metabolic disorders. Selective inhibition of LAR phosphatase activity by well characterized and well validated small molecules would provide key insights into the roles of LAR phosphatase in health and disease, but identifying selective inhibitors of LAR phosphatase activity has been challenging. Recently, we described potent and selective inhibition of LAR phosphatase activity by the fungal natural product illudalic acid. Here we provide a detailed biochemical characterization of the adduct formed between LAR phosphatase and illudalic acid. A mass spectrometric analysis indicates that two cysteine residues are covalently labeled by illudalic acid and a related analog. Mutational analysis supports the hypothesis that inhibition of LAR phosphatase activity is due primarily to the adduct with the catalytic cysteine residue. A computational study suggests potential interactions between the illudalic acid moiety and the enzyme active site. Taken together, these data offer novel insights into the mechanism of inhibition of LAR phosphatase activity by illudalic acid.


Asunto(s)
Cumarinas , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores , Humanos , Cumarinas/química , Cumarinas/farmacología , Cisteína/química , Cisteína/genética , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/antagonistas & inhibidores , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/química , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/genética
2.
BMC Nephrol ; 23(1): 6, 2022 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-34979953

RESUMEN

BACKGROUND: African American (AA) recipients of deceased-donor (DD) kidney transplants (KT) have shorter allograft survival than recipients of other ethnic groups. Reasons for this disparity encompass complex interactions between donors and recipients characteristics. METHODS: Outcomes from 3872 AA and 19,719 European American (EA) DDs who had one kidney transplanted in an AA recipient and one in an EA recipient were analyzed. Four donor/recipient pair groups (DRP) were studied, AA/AA, AA/EA, EA/AA, and EA/EA. Survival random forests and Cox proportional hazard models were fitted to rank and evaluate modifying effects of DRP on variables associated with allograft survival. These analyses sought to identify factors contributing to the observed disparities in transplant outcomes among AA and EA DDKT recipients. RESULTS: Transplant era, discharge serum creatinine, delayed graft function, and DRP were among the top predictors of allograft survival and mortality among DDKT recipients. Interaction effects between DRP with the kidney donor risk index and transplant era showed significant improvement in allograft survival over time in EA recipients. However, AA recipients appeared to have similar or poorer outcomes for DDKT performed after 2010 versus before 2001; allograft survival hazard ratios (95% CI) were 1.15 (0.74, 1.76) and 1.07 (0.8, 1.45) for AA/AA and EA/AA, compared to 0.62 (0.54, 0.71) and 0.5 (0.41, 0.62) for EA/EA and AA/EA DRP, respectively. Recipient mortality improved over time among all DRP, except unemployed AA/AAs. Relative to DDKT performed pre-2001, employed AA/AAs had HR = 0.37 (0.2, 0.69) versus 0.59 (0.31, 1.11) for unemployed AA/AA after 2010. CONCLUSION: Relative to DDKT performed before 2001, similar or worse overall DCAS was observed among AA/AAs, while EA/EAs experienced considerable improvement regardless of employment status, KDRI, and EPTS. AA recipients of an AA DDKT, especially if unemployed, had worse allograft survival and mortality and did not appear to benefit from advances in care over the past 20 years.


Asunto(s)
Negro o Afroamericano/psicología , Empleo , Fallo Renal Crónico/etnología , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Adulto , Femenino , Supervivencia de Injerto , Humanos , Fallo Renal Crónico/mortalidad , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Factores Raciales , Donantes de Tejidos , Trasplante Homólogo , Estados Unidos/epidemiología
3.
Am J Transplant ; 21(5): 1866-1877, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33052625

RESUMEN

Inflammation in areas of fibrosis (i-IFTA) in posttransplant biopsies is part of the diagnostic criteria for chronic active TCMR (CA TCMR -- i-IFTA ≥ 2, ti ≥ 2, t ≥ 2). We evaluated i-IFTA and CA TCMR in the DeKAF indication biopsy cohorts: prospective (n = 585, mean time to biopsy = 1.7 years); cross-sectional (n = 458, mean time to biopsy = 7.8 years). Grouped by i-IFTA scores, the 3-year postbiopsy DC-GS is similar across cohorts. Although a previous acute rejection episode (AR) was more common in those with i-IFTA on biopsy, the majority of those with i-IFTA had not had previous AR. There was no association between type of previous AR (AMR, TCMR) and presence of i-IFTA. In both cohorts, i-IFTA was associated with markers of both cellular (increased Banff i, t, ti) and humoral (increased g, ptc, C4d, DSA) activity. Biopsies with i-IFTA = 1 and i-IFTA ≥ 2 with concurrent t ≥ 2 and ti ≥ 2 had similar DC-GS. These results suggest that (a) i-IFTA≥1 should be considered a threshold for diagnoses incorporating i-IFTA, ti, and t; (b) given that i-IFTA ≥ 2,t ≥ 2, ti ≥ 2 can occur in the absence of preceding TCMR and that the component histologic scores (i-IFTA,t,ti) each indicate an acute change (albeit i-IFTA on the nonspecific background of IFTA), the diagnostic category "CA TCMR" should be reconsidered.


Asunto(s)
Rechazo de Injerto , Trasplante de Riñón , Biopsia , Estudios Transversales , Rechazo de Injerto/diagnóstico , Rechazo de Injerto/etiología , Supervivencia de Injerto , Humanos , Inflamación , Estudios Prospectivos , Linfocitos T
4.
Org Biomol Chem ; 19(48): 10596-10600, 2021 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-34847212

RESUMEN

Developing an efficient, concise synthesis of the fungal natural product illudalic acid has been a long-standing challenge, made more pressing by the recent discovery that illudalic acid and analogs are selective phosphatase inhibitors. Syntheses of illudalic acid have become progressively more efficient over the decades yet remain strategically grounded in a 17-step synthesis reported in 1977. Here we validate a two-step process-convergent [4 + 2] benzannulation and one-pot coordinated functional group manipulations-for preparing the key trifunctional pharmacophore of illudalic acid. The modular building blocks are readily available in 2-3 steps, for a longest linear sequence (LLS) of 5 steps to illudalic acid from 3,3-dimethylcyclopentanone. A small collection of analogous indanes and tetralins featuring the same pharmacophore were prepared by a similar route. These compounds potently and selectively inhibit the human leukocyte common antigen-related (LAR) subfamily of protein tyrosine phosphatases (PTPs). Evidence supporting a postulated covalent ligation mechanism is provided herein.


Asunto(s)
Cumarinas
5.
Am J Transplant ; 20(3): 641-652, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31566885

RESUMEN

Work relative value unit (wRVU)-based fee schedules are predominantly used by both the Centers for Medicare & Medicaid Services (CMS) and private payers to determine the payments for physicians' clinical productivity. However, under the Affordable Care Act, CMS is transitioning into a value-based payment structure that rewards patient-oriented outcomes and cost savings. Moreover, in the context of solid organ transplantation, physicians and surgeons conduct many activities that are neither billable nor accounted for in the wRVU models. New compensation models for transplant professionals must (1) justify payments for nonbillable work related to transplant activity/procedures; (2) capture the entire academic, clinical, and relationship-building work effort as part of RVU determination; and (3) move toward a value-based compensation scheme that aligns the incentives for physicians, surgeons, transplant center, payers, and patients. In this review, we provide an example of redesigning RVUs to address these challenges in compensating transplant physicians and surgeons. We define a customized RVU (cRVU) for activities that typically do not generate wRVUs and create an outcome value unit (OVU) measure that incorporates outcomes and cost savings into RVUs to include value-based compensation.


Asunto(s)
Patient Protection and Affordable Care Act , Cirujanos , Anciano , Humanos , Medicare , Escalas de Valor Relativo , Estados Unidos
6.
Am J Transplant ; 20(9): 2509-2521, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32185865

RESUMEN

Inflammation in areas of fibrosis (i-IFTA) in posttransplant biopsy specimens has been associated with decreased death-censored graft survival (DC-GS). Additionally, an i-IFTA score ≥ 2 is part of the diagnostic criteria for chronic active TCMR (CA TCMR). We examined the impact of i-IFTA and t-IFTA (tubulitis in areas of atrophy) in the first biopsy for cause after 90 days posttransplant (n = 598); mean (SD) 1.7 ± 1.4 years posttransplant. I-IFTA, present in 196 biopsy specimens, was strongly correlated with t-IFTA, and Banff i. Of the 196, 37 (18.9%) had a previous acute rejection episode; 96 (49%) had concurrent i score = 0. Unlike previous studies, i-IFTA = 1 (vs 0) was associated with worse 3-year DC-GS: (i-IFTA = 0, 81.7%, [95% CI 77.7 to 85.9%]); i-IFTA = 1, 68.1%, [95% CI 59.7 to 77.6%]; i-IFTA = 2, 56.1%, [95% CI 43.2 to 72.8%], i-IFTA = 3, 48.5%, [95% CI 31.8 to 74.0%]). The association of i-IFTA with decreased DC-GS remained significant when adjusted for serum creatinine at the time of the biopsy, Banff i, ci and ct, C4d and DSA. T-IFTA was similarly associated with decreased DC-GS. Of these indication biopsies, those with i-IFTA ≥ 2, without meeting other criteria for CA TCMR had similar postbiopsy DC-GS as those with CA TCMR. Those with i-IFTA = 1 and t ≥ 2, ti ≥ 2 had postbiopsy DC-GS similar to CA TCMR. Biopsies with i-IFTA = 1 had similar survival as CA TCMR when biopsy specimens also met Banff criteria for TCMR and/or AMR. Studies of i-IFTA and t-IFTA in additional cohorts, integrating analyses of Banff scores meeting criteria for other Banff diagnoses, are needed.


Asunto(s)
Rechazo de Injerto , Trasplante de Riñón , Biopsia , Fibrosis , Rechazo de Injerto/diagnóstico , Rechazo de Injerto/etiología , Humanos , Inflamación/etiología , Estudios Prospectivos
7.
Ann Surg ; 271(1): 177-183, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-29781845

RESUMEN

OBJECTIVE: To examine the largest single-center experience of simultaneous kidney/pancreas transplantation (SPK) transplantation among African-Americans (AAs). BACKGROUND: Current dogma suggests that AAs have worse survival following SPK than white recipients. We hypothesize that this national trend may not be ubiquitous. METHODS: From August 30, 1999, through October 1, 2014, 188 SPK transplants were performed at the University of Alabama at Birmingham (UAB) and 5523 were performed at other US centers. Using Kaplan-Meier survival estimates and Cox proportional hazards regression, we examined the influence of recipient ethnicity on survival. RESULTS: AAs comprised 36.2% of the UAB cohort compared with only 19.1% nationally (P < 0.01); yet, overall, 3-year graft survival was statistically higher among UAB than US cohort (kidney: 91.5% vs 87.9%, P = 0.11; pancreas: 87.4% vs 81.3%; P = 0.04, respectively) and persisted on adjusted analyses [kidney adjusted hazard ratio (aHR): 0.58, 95% confidence interval (95% CI) 0.35-0.97, P = 0.04; pancreas aHR: 0.54, 95% CI 0.34-0.85, P = 0.01]. Among the UAB cohort, graft survival did not differ between AA and white recipients; in contrast, the US cohort experienced significantly lower graft survival rates among AA than white recipients (kidney 5 years: 76.5% vs 82.3%, P < 0.01; pancreas 5 years: 72.2% vs 76.3%, P = 0.01; respectively). CONCLUSION: Among a single-center cohort of SPK transplants overrepresented by AAs, we demonstrated similar outcomes among AA and white recipients and better outcomes than the US experience. These data suggest that current dogma may be incorrect. Identifying best practices for SPK transplantation is imperative to mitigate racial disparities in outcomes observed at the national level.


Asunto(s)
Negro o Afroamericano , Predicción , Rechazo de Injerto/etnología , Trasplante de Riñón , Trasplante de Páncreas , Sistema de Registros , Adolescente , Adulto , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Estados Unidos/epidemiología , Adulto Joven
8.
Clin Transplant ; 34(6): e13827, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32080893

RESUMEN

Two renal-risk variants in the apolipoprotein L1 gene (APOL1) in African American (AA) deceased donors (DD) are associated with shorter renal allograft survival after transplantation. To identify additional genes contributing to allograft survival, a genome-wide association study was performed in 532 AA DDs. Phenotypic data were obtained from the Scientific Registry of Transplant Recipients. Association and single-nucleotide polymorphism (SNP)-by-APOL1 interaction tests were conducted using death-censored renal allograft survival accounting for relevant covariates. Replication and inverse-variance-weighted meta-analysis were performed using data from 250 AA DD in the Genomics of Transplantation study. Accounting for APOL1, multiple SNPs near the Nudix Hydrolase 7 gene (NUDT7) showed strong independent effects (P = 1.6 × 10-8 -2.2 × 10-8 ). Several SNPs in the Translocation protein SEC63 homolog (SEC63; P = 2 × 10-9 -3.7 × 10-8 ) and plasmacytoma variant translocation 1 (PVT1) genes (P = 4.0 × 10-8 -7 × 10-8 ) modified the effect of APOL1 on allograft survival. SEC63 is expressed in human renal tubule cells and glomeruli, and PVT1 is associated with diabetic kidney disease. Overall, associations were detected for 41 SNPs (P = 2 × 10-9 -5 × 10-8 ) contributing independently or interacting with APOL1 to impact renal allograft survival after transplantation from AA DD. Given the small sample size of the discovery and replication sets, independent validations and functional genomic efforts are needed to validate these results.


Asunto(s)
Apolipoproteína L1 , Rechazo de Injerto/genética , Trasplante de Riñón , Negro o Afroamericano/genética , Apolipoproteína L1/genética , Estudio de Asociación del Genoma Completo , Humanos , Lipoproteínas HDL/genética
9.
J Org Chem ; 85(21): 13429-13437, 2020 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-32830978

RESUMEN

The fungal metabolite illudinine is prepared in seven steps and ca. 55% overall yield from dimedone using an "open and shut" (ring-opening and ring-closing) strategy. Tandem ring-opening fragmentation and olefination of dimedone establishes alkyne and vinylarene functionality linked by a neopentylene tether. Oxidative cycloisomerization then provides the illudinine framework. The key innovation in this second-generation synthesis of illudinine is the use of the nitrile functional group, rather than an ester, as the functional precursor to the carboxylic acid of illudinine. The small, linear nitrile (C≡N) is associated with improved selectivity, π-conjugation, and reactivity at multiple points in the synthetic sequence relative to the carboxylic acid ester. Preliminary assays indicate that illudinine and several related synthetic analogues are monoamine oxidase inhibitors, which is the first reported indication of biological activity associated with this natural product. Illudinine was found to inhibit monoamine oxidase B (MAO-B) with an IC50 of 18 ± 7.1 µM in preliminary assays.


Asunto(s)
Inhibidores de la Monoaminooxidasa , Monoaminooxidasa , Ciclohexanonas , Monoaminooxidasa/metabolismo , Inhibidores de la Monoaminooxidasa/farmacología , Sesquiterpenos , Relación Estructura-Actividad
10.
Am J Transplant ; 19(5): 1432-1443, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30506642

RESUMEN

The DeKAF study was developed to better understand the causes of late allograft loss. Preliminary findings from the DeKAF cross-sectional cohort (with follow-up < 20 months) have been published. Herein, we present long-term outcomes in those recipients (mean follow-up ± SD, 6.6 ± 0.7 years). Eligibility included being transplanted prior to October 1, 2005; serum creatinine ≤ 2.0 mg/dL on January 1, 2006; and subsequently developing new-onset graft dysfunction leading to a biopsy. Mean time from transplant to biopsy was 7.5 ± 6.1 years. Histologic findings and DSA were studied in relation to postbiopsy outcomes. Long-term follow-up confirms and expands the preliminary results of each of 3 studies: (1) increasing inflammation in area of atrophy (irrespective of inflammation in nonscarred areas [Banff i]) was associated with increasingly worse postbiopsy death-censored graft survival; (2) hierarchical analysis based on Banff scores defined clusters (entities) that differed in long-term death-censored graft survival; and (3) C4d-/DSA- recipients had significantly better (and C4d+/DSA+ worse) death-censored graft survival than other groups. C4d+/DSA- and C4d-/DSA+ had similar intermediate death-censored graft survival. Clinical and histologic findings at the time of new-onset graft dysfunction define high- vs low-risk groups for long-term death-censored graft survival, even years posttransplant. These findings can help differentiate groups for potential intervention studies.


Asunto(s)
Atrofia/etiología , Rechazo de Injerto/etiología , Inflamación/etiología , Fallo Renal Crónico/cirugía , Trasplante de Riñón/efectos adversos , Complicaciones Posoperatorias , Atrofia/patología , Estudios de Cohortes , Complemento C4b/inmunología , Complemento C4b/metabolismo , Estudios Transversales , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/patología , Supervivencia de Injerto , Humanos , Inflamación/patología , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo
11.
Am J Transplant ; 19(7): 1888-1895, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31012525

RESUMEN

In accordance with the National Organ Transplant Act and Department of Health and Human Services' Final Rule, the Scientific Registry of Transplant Recipients (SRTR) publicly releases biannual program-specific reports that include analyses of transplant centers' risk-adjusted waitlist mortality, organ acceptance ratios, transplant rates, and graft and patient survival. Since the inception of these center metrics, 1-year posttransplant graft and patient survival have improved, and center variation has decreased, casting uncertainty on their clinical relevance. The SRTR has recently modified center evaluations by ranking centers into 5 tiers rather than 3 tiers in an attempt to discriminate between programs performing within a tight range, further exacerbating this uncertainty. The American Society of Transplantation/American Society of Transplant Surgeons convened an expert taskforce to examine both the utility and unintended consequences of transplant center metrics. Estimates of center variation in outcomes in adjacent tiers are imprecise and fleeting, but can result in consequential changes in clinician and center behavior. The taskforce has concerns that current metrics, based principally on 1-year graft and patient survival, provide minimal if any benefit in informing patient choice and access to transplantation, with the untoward effect of decreased utilization of organs and restriction of research and innovation.


Asunto(s)
Trasplante , Humanos , Garantía de la Calidad de Atención de Salud , Sistema de Registros , Obtención de Tejidos y Órganos , Listas de Espera
12.
Am J Transplant ; 19(8): 2241-2251, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30809941

RESUMEN

The use of procurement biopsies in deceased donor kidney acceptance is controversial. We analyzed Scientific Registry of Transplant Recipients data (n = 59 328 allografts, 2014-2018) to describe biopsy practices across US organ procurement organizations (OPOs) and examine relationships with discards, using hierarchical modeling to account for OPO and donor factors. Median odds ratios (MORs) provide the median of the odds that allografts with identical reported traits would be biopsied or discarded from 2 randomly drawn OPOs. Biopsies were obtained for 52.7% of kidneys. Biopsy use rose in a graded manner with kidney donor profile index (KDPI). Biopsy rates differed significantly among OPOs (22.8% to 77.5%), even after adjustment for KDPI and other donor factors. Discard rates also varied from 6.6% to 32.1% across OPOs. After adjustment for donor factors and OPO, biopsy was associated with more than 3 times the likelihood of discard (adjusted odds ratio [95%LCL aOR95%UCL ], 3.29 3.513.76 ). This association was most pronounced for low-risk (KDPI <20) kidneys (aOR, 5.45 6.477.69 ), with minimal impact at KDPI >85 (aOR, 0.88 1.151.51 ). Adjusted MORs for kidney discard and biopsy were greatest for low-risk kidneys. Reducing the rate of unnecessary biopsy and improving the accuracy of histologic assessments in higher KDPI organs may help reduce graft discard rates.


Asunto(s)
Selección de Donante/métodos , Trasplante de Riñón/métodos , Donantes de Tejidos/provisión & distribución , Obtención de Tejidos y Órganos/métodos , Biopsia , Selección de Donante/normas , Estudios de Seguimiento , Humanos , Trasplante de Riñón/normas , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Obtención de Tejidos y Órganos/normas , Receptores de Trasplantes
13.
Am J Transplant ; 19(2): 475-487, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-29900661

RESUMEN

Tolerance induction through simultaneous hematopoietic stem cell and renal transplantation has shown promising results, but it is hampered by the toxicity of preconditioning therapies and graft-versus-host disease (GVHD). Moreover, renal function has never been compared to conventionally transplanted patients, thus, whether donor-specific tolerance results in improved outcomes remains unanswered. We collected follow-up data of published cases of renal transplantations after hematopoietic stem cell transplantation from the same donor and compared patient and transplant kidney survival as well as function with caliper-matched living-donor renal transplantations from the Austrian dialysis and transplant registry. Overall, 22 tolerant and 20 control patients were included (median observation period 10 years [range 11 months to 26 years]). In the tolerant group, no renal allograft loss was reported, whereas 3 were lost in the control group. Median creatinine levels were 85 µmol/l (interquartile range [IQR] 72-99) in the tolerant cohort and 118 µmol/l (IQR 99-143) in the control group. Mixed linear-model showed around 29% lower average creatinine levels throughout follow-up in the tolerant group (P < .01). Our data clearly show stable renal graft function without long-term immunosuppression for many years, suggesting permanent donor-specific tolerance. Thus sequential transplantation might be an alternative approach for future studies targeting tolerance induction in renal allograft recipients.


Asunto(s)
Supervivencia de Injerto , Trasplante de Células Madre Hematopoyéticas/mortalidad , Fallo Renal Crónico/mortalidad , Trasplante de Riñón/mortalidad , Donadores Vivos/provisión & distribución , Adolescente , Adulto , Aloinjertos , Estudios de Casos y Controles , Terapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Inmunosupresores/uso terapéutico , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Tasa de Supervivencia , Trasplante Homólogo , Adulto Joven
14.
Xenotransplantation ; 26(2): e12471, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30456901

RESUMEN

Renal allotransplantation clearly offers better survival and quality of life for end-stage renal disease (ESRD) patients than chronic dialysis. The median waiting time for a deceased donor kidney in a suitable ESRD patient is 3.9 years. The initial candidates for pig kidney xenotransplantation will be those with ESRD unlikely to receive an allograft within a reasonable period of time. It is thus reasonable to ascertain whether clinical trials of xenotransplantation might likewise offer superior outcomes. Chronic dialysis in patients with ESRD is associated with poor quality of life, significant morbidity, and relatively high mortality, with only 56% surviving 3 years and 42% at 5 years. However, a significant number of these patients, because of comorbidities, frailty, etc, would not be considered for renal allotransplantation and likely not for xenotransplantation. As genetically engineered pig kidneys have satisfactorily supported life in immunosuppressed nonhuman primates for many months or even more than a year, consideration in carefully selected patients could be given to pig kidney xenotransplantation. We suggest that, in order to give a patient the best possible outcome, the pig kidney could be transplanted pre-emptively (before dialysis is initiated). If it fails at any stage, the patient would then begin chronic dialysis and continue to await an allograft. The present (limited) evidence is that failure of a pig graft would not be detrimental to a subsequent allograft.


Asunto(s)
Xenoinjertos/inmunología , Fallo Renal Crónico/inmunología , Trasplante de Riñón , Diálisis Renal , Trasplante Heterólogo , Animales , Supervivencia de Injerto/inmunología , Humanos , Trasplante de Riñón/efectos adversos , Trasplante Heterólogo/métodos
15.
Am J Transplant ; 18(6): 1494-1501, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29316241

RESUMEN

Outcomes of patients receiving solid organ transplants in the United States are systematically aggregated into bi-annual Program-Specific Reports (PSRs) detailing risk-adjusted survival by transplant center. Recently, the Scientific Registry of Transplant Recipients (SRTR) issued 5-tier ratings evaluating centers based on risk-adjusted 1-year graft survival. Our primary aim was to examine the reliability of 5-tier ratings over time. Using 10 consecutive PSRs for adult kidney transplant centers from June 2012 to December 2016 (n = 208), we applied 5-tier ratings to center outcomes and evaluated ratings over time. From the baseline period (June 2012), 47% of centers had at least a 1-unit tier change within 6 months, 66% by 1 year, and 94% by 3 years. Similarly, 46% of centers had at least a 2-unit tier change by 3 years. In comparison, 15% of centers had a change in the traditional 3-tier rating at 3 years. The 5-tier ratings at 4 years had minimal association with baseline rating (Kappa 0.07, 95% confidence interval [CI] -0.002 to 0.158). Centers had a median of 3 different 5-tier ratings over the period (q1 = 2, q3 = 4). Findings were consistent for center volume, transplant rate, and baseline 5-tier rating. Cumulatively, results suggest that 5-tier ratings are highly volatile, limiting their utility for informing potential stakeholders, particularly transplant candidates given expected waiting times between wait listing and transplantation.


Asunto(s)
Instituciones de Salud/normas , Trasplante de Órganos/normas , Adulto , Humanos , Estados Unidos
16.
Am J Transplant ; 18(5): 1158-1167, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29139625

RESUMEN

Beyond the first posttransplant year, 3% of kidney transplants fail annually. In a prospective, multicenter cohort study, we tested the relative impact of early versus late events on risk of long-term death-censored graft failure (DCGF). In grafts surviving at least 90 days, early events (acute rejection [AR] and delayed graft function [DGF] before day 90) were recorded; serum creatinine (Cr) at day 90 was defined as baseline. Thereafter, a 25% rise in serum Cr or new-onset proteinuria triggered graft biopsy (index biopsy, IBx), allowing comparison of risk of DCGF associated with early events (AR, DGF, baseline serum Cr >2.0 mg/dL) to that associated with later events (IBx). Among 3678 patients followed for 4.7 ± 1.9 years, 753 (20%) had IBx at a median of 15.3 months posttransplant. Early AR (HR = 1.77, P < .001) and elevated Cr at Day 90 (HR = 2.56, P < .0001) were associated with increased risk of DCGF; however, later-onset dysfunction requiring IBx had far greater impact (HR = 13.8, P < .0001). At 90 days, neither clinical characteristics nor early events distinguished those who subsequently did or did not undergo IBx or suffer DCGF. To improve long-term kidney allograft survival, management paradigms should promote prompt diagnosis and treatment of both early and later events.


Asunto(s)
Funcionamiento Retardado del Injerto/etiología , Rechazo de Injerto/etiología , Fallo Renal Crónico/cirugía , Trasplante de Riñón/efectos adversos , Complicaciones Posoperatorias , Adulto , Funcionamiento Retardado del Injerto/patología , Femenino , Estudios de Seguimiento , Rechazo de Injerto/patología , Supervivencia de Injerto , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Factores de Tiempo
17.
Ann Surg ; 267(6): 1161-1168, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-28187045

RESUMEN

OBJECTIVE: The aim of this study was to develop a novel chronic kidney disease (CKD) risk prediction tool for young potential living kidney donors. SUMMARY OF BACKGROUND DATA: Living kidney donor selection practices have evolved from examining individual risk factors to a risk calculator incorporating multiple characteristics. Owing to limited long-term data and lack of genetic information, current risk tools lack precision among young potential living kidney donors, particularly African Americans (AAs). METHODS: We identified a cohort of young adults (18-30 years) with no absolute contraindication to kidney donation from the longitudinal cohort study Coronary Artery Risk Development in Young Adults. Risk associations for CKD (estimated glomerular filtration rate <60 mL/min/1.73 m) were identified and assigned weighted points to calculate risk scores. RESULTS: A total of 3438 healthy adults were identified [mean age 24.8 years; 48.3% AA; median follow-up 24.9 years (interquartile range: 24.5-25.2)]. For 18-year olds, 25-year projected CKD risk varied by ethnicity and sex even without baseline clinical and genetic abnormalities; risk was 0.30% for European American (EA) women, 0.52% for EA men, 0.52% for AA women, 0.90% for AA men. Among 18-year-old AAs with apolipoprotein L1 gene (APOL1) renal-risk variants without baseline abnormalities, 25-year risk significantly increased: 1.46% for women and 2.53% for men; among those with 2 APOL1 renal-risk variants and baseline abnormalities, 25-year risk was higher: 2.53% to 6.23% for women and 4.35% to 10.58% for men. CONCLUSIONS: Young AAs were at highest risk for CKD, and APOL1 renal-risk variants drove some of this risk. Understanding the genetic profile of young AA potential living kidney donors in the context of baseline health characteristics may help to inform candidate selection and counseling.


Asunto(s)
Apolipoproteína L1/genética , Genotipo , Trasplante de Riñón/efectos adversos , Donadores Vivos , Insuficiencia Renal Crónica/etiología , Medición de Riesgo/métodos , Adolescente , Adulto , Negro o Afroamericano/genética , Femenino , Estudios de Seguimiento , Humanos , Masculino , Insuficiencia Renal Crónica/genética , Población Blanca/genética , Adulto Joven
18.
Kidney Int ; 91(3): 699-703, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-28041626

RESUMEN

Determining candidacy for live kidney donation among obese individuals remains challenging. Among healthy non-donors, body mass index (BMI) above 30 is associated with a 16% increase in risk of end-stage renal disease (ESRD). However, the impact on the ESRD risk attributable to donation and living with only one kidney remains unknown. Here we studied the risk of ESRD associated with obesity at the time of donation among 119 769 live kidney donors in the United States. Maximum follow-up was 20 years. Obese (BMI above 30) live kidney donors were more likely male, African American, and had higher blood pressure. Estimated risk of ESRD 20 years after donation was 93.9 per 10 000 for obese; significantly greater than the 39.7 per 10 000 for non-obese live kidney donors. Adjusted for age, sex, ethnicity, blood pressure, baseline estimated glomerular filtration rate, and relationship to recipient, obese live kidney donors had a significant 86% increased risk of ESRD compared to their non-obese counterparts (adjusted hazard ratio 1.86; 95% confidence interval 1.05-3.30). For each unit increase in BMI above 27 kg/m2 there was an associated significant 7% increase in ESRD risk (1.07, 1.02-1.12). The impact of obesity on ESRD risk was similar for male and female donors, African American and Caucasian donors, and across the baseline estimated glomerular filtration rate spectrum. These findings may help to inform selection criteria and discussions with persons considering living kidney donation.


Asunto(s)
Selección de Donante , Fallo Renal Crónico/epidemiología , Trasplante de Riñón/efectos adversos , Donadores Vivos , Nefrectomía/efectos adversos , Obesidad/epidemiología , Adulto , Negro o Afroamericano , Índice de Masa Corporal , Femenino , Tasa de Filtración Glomerular , Humanos , Hipertensión/epidemiología , Incidencia , Estimación de Kaplan-Meier , Riñón/fisiopatología , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/mortalidad , Fallo Renal Crónico/fisiopatología , Trasplante de Riñón/métodos , Trasplante de Riñón/mortalidad , Masculino , Persona de Mediana Edad , Nefrectomía/mortalidad , Obesidad/diagnóstico , Obesidad/mortalidad , Pronóstico , Modelos de Riesgos Proporcionales , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Factores de Tiempo , Estados Unidos/epidemiología , Población Blanca
19.
Trans Am Clin Climatol Assoc ; 127: 350-361, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28066070

RESUMEN

Since the 1950s, care for kidney transplant recipients in the United States has evolved around a model in which clinical management, quality metrics, and financial underpinnings are focused around the surgical procedure itself reflecting the concept that perioperative and short-term interventions are primary determinants of success. In the current era, short-term results are indeed excellent, but long-term success remains elusive for many. Emerging data, particularly a newfound understanding of donor-specific antibody and its consequences, now challenge the concept that late graft failure is the consequence of early events. Several major longitudinal studies, including the long-term Deterioration of Kidney Allograft Function (DeKAF) project and Clinical Trials in Organ Transplantation-09 (CTOT-09), highlight the primacy of later events in influencing long-term outcomes after kidney transplantation. Proper long-term care and monitoring of kidney recipients, with timely diagnosis and treatment of identifiable injury, offers the best prospect of improving long-term graft survival.


Asunto(s)
Supervivencia de Injerto , Trasplante de Riñón , Rechazo de Injerto , Humanos , Riñón , Tasa de Supervivencia , Resultado del Tratamiento , Estados Unidos
20.
J Am Soc Nephrol ; 26(5): 1017-9, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25255922

RESUMEN

The short- and long-term effects of unilateral nephrectomy on living donors have been important considerations for 60 years. Short-term risk is well established (0.03% mortality and <1% risk of major morbidity), but characterization of long-term risk is evolving. Relative to the general population, risk of mortality, ESRD, hypertension, proteinuria, and cardiovascular disease is comparable or lower. However, new studies comparing previous donors with equally healthy controls indicate increased risk of metabolic derangements (particularly involving calcium homeostasis), renal failure, and possibly, mortality. We discuss how these results should be interpreted and their influence on the practice of living donor kidney transplantation.


Asunto(s)
Trasplante de Riñón , Donadores Vivos , Nefrectomía/efectos adversos , Humanos , Medición de Riesgo
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