RESUMO
BACKGROUND: Ischemia-reperfusion injury (IRI) causes significant morbidity in liver transplantation among other medical conditions. IRI following liver transplantation contributes to poor outcomes and early graft loss. Histone/protein deacetylases (HDACs) regulate diverse cellular processes, play a role in mediating tissue responses to IRI, and may represent a novel therapeutic target in preventing IRI in liver transplantation. METHODS: Using a previously described standardized model of murine liver warm IRI, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were assessed at 24 and 48 h after reperfusion to determine the effect of different HDAC inhibitors. RESULTS: Broad HDAC inhibition with trichostatin-A (TSA) was protective against hepatocellular damage (Pâ <â 0.01 for AST and Pâ <â 0.05 for ALT). Although HDAC class I inhibition with MS-275 provided statistically insignificant benefit, tubastatin-A (TubA), an HDAC6 inhibitor with additional activity against HDAC10, provided significant protection against liver IRI (Pâ <â 0.01 for AST and Pâ <â 0.001 for ALT). Surprisingly genetic deletion of HDAC6 or -10 did not replicate the protective effects of HDAC6 inhibition with TubA, whereas treatment with an HDAC6 BUZ-domain inhibitor, LakZnFD, eliminated the protective effect of TubA treatment in liver ischemia (Pâ <â 0.01 for AST and Pâ <â 0.01 for ALT). CONCLUSIONS: Our findings suggest TubA, a class IIb HDAC inhibitor, can mitigate hepatic IRI in a manner distinct from previously described class I HDAC inhibition and requires the HDAC6 BUZ-domain activity. Our data corroborate previous findings that HDAC targets for therapeutic intervention of IRI may be tissue-specific, and identify HDAC6 inhibition as a possible target in the treatment of liver IRI.
RESUMO
BACKGROUND: There is increasing evidence that estrogen is responsible for improved outcomes in female kidney transplant recipients. Although the exact mechanism is not yet known, estrogen appears to exert its protective effects by ameliorating ischemia-reperfusion injury (IRI). In this study, we have examined whether the beneficial effects of exogenous estrogen in renal IRI are replicated by therapy with any one of several selective estrogen receptor modulators. METHODS: C57BL/6 adult mice underwent standardized warm renal ischemia for 28 min after being injected with the selective estrogen receptor modulators, raloxifene, lasofoxifene, tamoxifen, bazedoxifene, or control vehicle (dimethyl sulfoxide), at 16 and 1 h before IRI. Plasma concentrations of blood urea nitrogen and creatinine were assessed 24, 48, 72, and 96 h post-IRI. Tissue was collected 30 d postischemia for fibrosis analysis using Sirius Red staining. RESULTS: Raloxifene treatment in female mice resulted in significantly lower blood urea nitrogen and creatinine after IRI and significantly lower fibrosis 30 d following IRI. CONCLUSIONS: Raloxifene is protective against both acute kidney injury and fibrosis resulting from renal IRI in a mouse model.
Assuntos
Injúria Renal Aguda , Traumatismo por Reperfusão , Feminino , Camundongos , Animais , Cloridrato de Raloxifeno/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Creatinina , Dimetil Sulfóxido/farmacologia , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/patologia , Rim/patologia , Injúria Renal Aguda/prevenção & controle , Injúria Renal Aguda/patologia , Estrogênios/farmacologia , FibroseRESUMO
OBJECTIVE: The aim of this study was to determine graft function and survival for kidney transplants from deceased donors with acute kidney injury (AKI) that persists at the time of organ procurement. BACKGROUND: Kidneys from donors with AKI are often discarded and may provide an opportunity to selectively expand the donor pool. METHODS: Using Organ Procurement and Transplantation Network and DonorNet data, we studied adult kidney-only recipients between May 1, 2007 and December 31, 2016. DonorNet was used to characterize longitudinal creatinine trends and urine output. Donor AKI was defined using KDIGO guidelines and terminal creatinine ≥1.5 mg/dL. We compared outcomes between AKI kidneys versus "ideal comparator" kidneys from donors with no or resolved AKI stage 1 plus terminal creatinine <1.5mg/dL. We fit proportional hazards models and hierarchical linear regression models for the primary outcomes of all-cause graft failure (ACGF) and 12-month estimated glomerular filtration rate (eGFR), respectively. RESULTS: We identified 7660 donors with persistent AKI (33.2% with AKI stage 3) from whom ≥1 kidney was transplanted. Observed rates of ACGF within 3 years were similar between recipient groups (15.5% in AKI vs 15.1% ideal comparator allografts, P = 0.2). After risk adjustment, ACGF was slightly higher among recipients of AKI kidneys (adjusted hazard ratio 1.05, 95% confidence interval: 1.01-1.09). The mean 12-month eGFR for AKI kidney recipients was lower, but differences were not clinically important (56.6 vs 57.5 mL/min/1.73m 2 for ideal comparator kidneys; P < 0.001). There were 2888 kidneys discarded from donors with AKI, age ≤65 years, without hypertension or diabetes, and terminal creatinine ≤4 mg/dL. CONCLUSION: Kidney allografts from donors with persistent AKI are often discarded, yet those that were transplanted did not have clinically meaningful differences in graft survival and function.
Assuntos
Injúria Renal Aguda , Transplante de Rim , Adulto , Humanos , Idoso , Creatinina , Estudos de Coortes , Doadores de Tecidos , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Sobrevivência de Enxerto , Rim , Armazenamento e Recuperação da Informação , Estudos RetrospectivosRESUMO
BACKGROUND: The clinical impact of weakly reactive pretransplant donor-specific antibody (DSA) in kidney transplantation is controversial. While some evidence suggests that weakly reactive DSA can lead to rejection, it is unclear which patients are at risk for rejection and whether posttransplant changes in weakly reactive DSA are clinically meaningful. METHODS: We retrospectively studied 80 kidney transplant recipients with weakly reactive pretransplant DSA between 2007 and 2014. We performed a multivariate Cox regression analysis to identify immunologic factors most associated with risk of biopsy-proven rejection. RESULTS: Biopsy-proven rejection occurred in 13 of 80 (16%) patients. The presence of both class I and II DSA before transplant (hazards ratio 17.4, P < 0.01) and any posttransplant increase in DSA reactivity above a mean fluorescence intensity of 3000 (hazards ratio 7.8, P < 0.01) were each significantly associated with an increased risk of rejection, which primarily occurred within the first 18 months. CONCLUSIONS: Pretransplant DSA class and DSA kinetics after transplantation are useful prognostic indicators in patients with weak DSA reactivity. These results identify a small, high-risk patient group that warrants aggressive posttransplant DSA monitoring and may benefit from alternative donor selection.
RESUMO
RATIONALE & OBJECTIVE: A robust relationship between procedure volume and clinical outcomes has been demonstrated across many surgical fields. This study assessed whether a center volume-outcome relationship exists for contemporary kidney transplantation, specifically for diabetic recipients, older recipients (aged ≥65 years), and recipients of high kidney donor profile index (KDPI ≥ 85) kidneys. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adult kidney-only transplant recipients who underwent transplantation between 2009 and 2013 (N = 79,581). EXPOSURES: The primary exposure variable was center volume, categorized into quartiles based on the total kidney transplantation volume. Quartile 1 (Q1) centers performed a mean of fewer than 66 kidney transplantations per year, whereas Q4 centers performed a mean of more than 196 kidney transplantations per year. OUTCOMES: All-cause graft failure and mortality within 3 years of transplantation. ANALYTICAL APPROACH: Multivariable Cox frailty models were used to adjust for donor characteristics, recipient characteristics, and cold ischemia time. RESULTS: Minor differences in rates of 3-year deceased donor all-cause graft failure across quartiles of center volume were observed (14.9% for Q1 vs 16.7% for Q4), including in subgroups (diabetic recipients, 18.4% for Q1 vs 19.7% for Q4; older recipients, 19.4% for Q1 vs 22.5% for Q4; recipients of high KDPI kidneys, 26.5% for Q1 vs 26.5% for Q4). Results were similar for 3-year mortality. After adjustment for donor, recipient, and graft characteristics using Cox regression, center volume was not significantly associated with all-cause graft failure or mortality within 3 years, except that diabetic recipients at Q3 centers had slightly lower mortality (compared with Q1 centers, adjusted HR of 0.85 [95% CI, 0.73-0.99]). LIMITATIONS: Potential unmeasured confounding from patient comorbid conditions and organ selection. CONCLUSIONS: These findings provide little evidence that care in higher volume centers is associated with better adjusted outcomes for kidney transplant recipients, even in populations anticipated to be at increased risk for graft failure or death.
Assuntos
Hospitais com Alto Volume de Atendimentos/tendências , Hospitais com Baixo Volume de Atendimentos/tendências , Transplante de Rim/tendências , Obtenção de Tecidos e Órgãos/tendências , Transplantados , Idoso , Estudos de Coortes , Feminino , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/epidemiologia , Hospitais com Alto Volume de Atendimentos/normas , Hospitais com Baixo Volume de Atendimentos/normas , Humanos , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/cirurgia , Transplante de Rim/normas , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Obtenção de Tecidos e Órgãos/normas , Resultado do TratamentoRESUMO
Hospital readmissions after liver transplantation (LT) are common and associated with increased morbidity and cost. High readmission rates at our center motivated a change in practice with adoption of a nurse practitioner (NP)-based posttransplant care program. We sought to determine if this program was effective in reducing 30- and 90-day readmissions after LT and to identify variables associated with readmission. We performed a retrospective cohort study of all patients undergoing LT from July 1, 2014, to June 30, 2017, at a tertiary LT referral center. A NP-based posttransplant care program with weekend in-house nurse coordination providers and increased outpatient NP clinic availability was instituted on January 1, 2016. Postdischarge readmission rates at 30 and 90 days were compared in the pre-exposure and postexposure groups, adjusting for associated risk factors. A total of 362 patients were included in the analytic cohort. There were no significant differences in demographics, comorbidities, or index hospitalization characteristics between groups. In the adjusted analyses, the risk of readmission in the postexposure group was significantly reduced relative to baseline at 30 days (hazard ratio [HR] 0.60, 95% confidence interval [CI], 0.39-0.90; P = 0.02) and 90 days (HR, 0.49; 95% CI, 0.34-0.71; P < 0.001). Risk factors positively associated with 30-day readmission included peritransplant dialysis (HR, 1.70; 95% CI, 1.13-2.58; P = 0.01) and retransplant on index hospitalization (HR, 10.21; 95% CI, 3.39-30.75; P < 0.001). Male sex was protective against readmission (HR, 0.66; 95% CI, 0.45-0.97; P = 0.03). In conclusion, implementation of expanded NP-based care after LT was associated with significantly reduced 30- and 90-day readmission rates. LT centers and other service lines using significant postsurgical resources may be able to reduce readmissions through similar programs.
Assuntos
Doença Hepática Terminal/cirurgia , Transplante de Fígado/efeitos adversos , Profissionais de Enfermagem/organização & administração , Readmissão do Paciente/estatística & dados numéricos , Cuidados Pós-Operatórios , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/terapia , Papel Profissional , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Fatores de Tempo , Resultado do Tratamento , Estados UnidosRESUMO
Kidney paired exchange (KPE) constitutes 12% of all living donor kidney transplantations (LDKTs) in the United States. The success of KPE programs has prompted many in the liver transplant community to consider the possibility of liver paired exchange (LPE). Though the idea seems promising, the application has been limited to a handful of centers in Asia. In this article, we consider the indications, logistical issues, and ethics for establishing a LPE program in the United States with reference to the principles and advances developed from experience with KPE. Liver Transplantation 24 677-686 2018 AASLD.
Assuntos
Atenção à Saúde/organização & administração , Doação Dirigida de Tecido , Transplante de Rim/métodos , Transplante de Fígado/métodos , Doadores de Tecidos/provisão & distribuição , Atenção à Saúde/ética , Doação Dirigida de Tecido/ética , Seleção do Doador/organização & administração , Humanos , Consentimento Livre e Esclarecido , Transplante de Rim/ética , Transplante de Fígado/ética , Modelos Organizacionais , Avaliação de Programas e Projetos de Saúde , Doadores de Tecidos/ética , Estados Unidos , Fluxo de TrabalhoRESUMO
BACKGROUND: Patients with hepatocellular carcinoma (HCC) exceeding Milan criteria on explant pathology are at increased risk of recurrence and death. Discordance between contemporary magnetic resonance imaging (MRI) and explant pathology, and preoperative characteristics predictive of discordance are not well understood. METHODS: Patients who underwent orthotopic liver transplantation for HCC after preoperative MRI were identified in a prospectively collected institutional database (January 2003 to December 2013). Patients were dichotomized to "within" or "outside" Milan criteria by both imaging and explant pathologic evaluation. Binary logistic regression and Kaplan-Meier methodology were used to identify independent predictors of imaging/pathologic discordance and its impact on posttransplant survival. RESULTS: Of 318 patients with HCC meeting Milan criteria by MRI at the time of orthotopic liver transplantation, 248 (78.0%) remained within a pathological correlate of Milan criteria on explant examination. Understaging was associated with worse median recurrence-free survival (64.0 months vs 140.0 months, P = 0.002) and overall survival (96.0 months vs 143.0 months, P = 0.005), and did not vary between patients exceeding criteria due to tumor explant greater than 5 cm, more than 3 tumor foci, or a tumor greater than 3 cm in the setting of multifocality. Discordance was independently associated with an increasing serum alpha fetal protein level (odds ratio, 2.82; 95% confidence interval, 1.37-5.79; P = 0.005). CONCLUSIONS: Underestimating HCC burden before liver transplant remains frequent despite contemporary imaging technologies. Patients with an increasing alpha fetal protein before transplantation may benefit from more frequent testing or novel neoadjuvant therapies.
Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Transplante de Fígado , Imageamento por Ressonância Magnética , Estadiamento de Neoplasias/métodos , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/cirurgia , Tomada de Decisão Clínica , Bases de Dados Factuais , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Recidiva Local de Neoplasia , Valor Preditivo dos Testes , Intervalo Livre de Progressão , Reprodutibilidade dos Testes , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Carga TumoralRESUMO
BACKGROUND: Vascularized composite allografts (VCA) are novel, life-enhancing forms of transplantation (Tx). However, host immune responses to the various VCA components, especially those involving skin, are complex and make selection of appropriate therapy challenging. Although the interplay between Foxp3+ T regulatory (Treg) cells and CD4 and CD8 effector T cells is of central importance in determining the acceptance or rejection of solid organ allografts, there is little information available concerning the contribution of Treg cells to VCA survival. In addition, the effects of therapeutic expansion in vivo of host Treg cell populations on VCA survival are unknown. METHODS: We established a fully major histocompatibility complex-disparate (BALB/c- > C57BL/6) murine orthotopic forelimb Tx model to explore the benefits of pre- and post-Tx IL-2/anti-IL-2 monoclonal antibody complex (IL-2C) administration to expand the host Treg cell population and thereby attempt to promote Treg cell-dependent VCA survival. RESULTS: Both strategies expanded the Treg cell population in vivo and prolonged VCA survival (P < 0.001), but IL-2C administration pre-Tx led to significantly longer survival compared with IL-2C administration post-Tx (P < 0.01). In addition, compared with post-Tx therapy, pre-Tx therapy resulted in an increased ratio of Treg cells to CD8+ T cells (P < 0.001), reduced proliferation of CD4 and CD8 effector T cells, and reduced production of IFN-γ. Optimal effects were seen when combined with rapamycin therapy, whereas the combination of IL-2C therapy plus calcineurin inhibitor was counterproductive. CONCLUSIONS: Our studies involving different IL-2C-mediated Treg cell expansion strategies demonstrate that pre-Tx IL-2C therapy may be a useful component for developing strategies to promote VCA survival.
Assuntos
Aloenxertos Compostos , Membro Anterior/transplante , Sobrevivência de Enxerto/efeitos dos fármacos , Interleucina-2/farmacologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/imunologiaRESUMO
OBJECTIVE: This study aimed to compare the incidence of radiologically unrecognized (occult) hepatocellular carcinoma (HCC) lesions in explant hepatectomy specimens from orthotopic liver transplants (OLTs) performed for HCC with rates of HCC intrahepatic recurrence after resection. SUMMARY OF BACKGROUND DATA: Resection of HCC is associated with high rates of intrahepatic HCC recurrence. However, it is unclear whether these recurrences represent incomplete resection of unrecognized metastatic lesions from the primary tumor or subsequent de novo tumor formation due to inherent biological proclivity for HCC formation. METHODS: We collected patient, tumor, and pathology data on HCC patients treated surgically from 3696 OLTs in the Organ Procurement and Transplantation (OPTN) national database, 299 OLTs at a single transplant center, and 232 partial hepatectomies from a hepatobiliary cancer center. RESULTS: In the OPTN and high-volume transplant center cohorts, 37% and 42% of patients had occult HCC lesions on explant pathology, respectively. Among cancer center patients, the 2-year recurrence rate was 46%, and 74% of patients who recurred presented with liver only recurrence. CONCLUSION: Although the transplant and resection populations differ, occult multifocality is common in transplant explants and similar to the 46% early recurrence rate following partial hepatectomy. These data suggest that noncurative resection often results from occult intrahepatic multifocality present at the time of resection rather than a malignant predisposition of the remnant liver with de novo tumorigenesis.