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1.
Drug Alcohol Rev ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38773898

RESUMO

INTRODUCTION: Hepatitis C virus (HCV) prevalence is high in the mental health population. We sought to evaluate testing and treatment uptake for HCV following the implementation of a universal nurse led study in inpatient and outpatient mental health populations. METHODS: From January 2018 to December 2020, we screened mental health inpatients (n = 322) and community mental health patients (n = 615) for HCV with either specialist hepatology nurses or mental health nurses (mental health nurse). RESULTS: 75.5% (464/615) of community patients and 100% (322/322) of inpatients consented to screening, with an HCV antibody-positive prevalence of 12.7% (59/464) in community patients and 19.6% (63/322) in inpatients. RNA detectable prevalence was 4.0% (22/464) and 7.5% (24/322), respectively. Community patients who were screened by specialist hepatology nurses were more likely to consent to screening (94.4% vs. 45.7%, p < 0.001) but had lower proportion of HCV antibody (10.5% vs. 20.3%, p < 0.001) and RNA detectable (4.0% vs. 7.5%, p = 0.018) when compared to mental health nurse screening. Engagement with treatment was 27.0% of community mental health patients and 45.8% of mental health inpatients undergoing treatment. All patients undergoing treatment and underwent sustained viral response (SVR) testing achieved SVR. DISCUSSION AND CONCLUSIONS: Universal screening of HCV using a nurse-led model has high rates of success in mental health patients with high proportions undergoing screening, with no reduction in the rates of SVR achieved with DAA therapy compared to the general population. Further work is needed to bridge the gap between identification of HCV and treatment among mental health patients.

2.
Artif Organs ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528752

RESUMO

BACKGROUND: Normothermic machine perfusion (NMP) allows for the assessment and resuscitation of ex-vivo human livers prior to transplantation. Commercially available NMP systems are closed circuits that accumulate metabolic waste and cytokines over time, potentially limiting organ preservation times. Dialysis has been proposed as a method to remove waste and excess fluid from such systems. This study aimed to demonstrate the utility of integrating dialysis into a commercially available system by quantifying solute removal. METHODS: A dialysis filter was attached in parallel to a commercially available liver perfusion system. Three livers declined for transplantation were split before undergoing long-term NMP with blood using the modified system. During perfusion, dialysate flow rates were set in the range of 100-600 mL/h for short periods of time. At each flow rate, perfusate and spent dialysate samples were collected and analyzed for solute clearance. RESULTS: The addition of dialysis to a commercial NMP system removed water-soluble waste and helped regulate electrolyte concentrations. Interleukin-6 was successfully removed from the perfusate. Solute clearance was proportional to dialysate flow rate. A guide for our perfusion setup was created for the appropriate selection of dialysis flow rates and duration based on real-time perfusate composition. CONCLUSIONS: Dialysis circuits can efficiently remove waste and regulate perfusate composition, and can be easily incorporated to improve the performance of commercially available systems. Quantification of the effect of dialysis on perfusate composition enables refined dialysis control to optimize electrolyte profiles and avoid the over- or under-correction of key solutes.

3.
Am J Transplant ; 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38461883

RESUMO

The Banff Working Group on Liver Allograft Pathology met in September 2022. Participants included hepatologists, surgeons, pathologists, immunologists, and histocompatibility specialists. Presentations and discussions focused on the evaluation of long-term allograft health, including noninvasive and tissue monitoring, immunosuppression optimization, and long-term structural changes. Potential revision of the rejection classification scheme to better accommodate and communicate late T cell-mediated rejection patterns and related structural changes, such as nodular regenerative hyperplasia, were discussed. Improved stratification of long-term maintenance immunosuppression to match the heterogeneity of patient settings will be central to improving long-term patient survival. Such personalized therapeutics are in turn contingent on a better understanding and monitoring of allograft status within a rational decision-making approach, likely to be facilitated in implementation with emerging decision-support tools. Proposed revisions to rejection classification emerging from the meeting include the incorporation of interface hepatitis and fibrosis staging. These will be opened to online testing, modified accordingly, and subject to consensus discussion leading up to the next Banff conference.

4.
Transplantation ; 108(1): 198-203, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37202846

RESUMO

BACKGROUND: Normothermic machine perfusion permits the ex vivo preservation of human livers before transplantation. Long-term perfusion for days-to-weeks provides the opportunity for enhanced pretransplant assessment and potential regeneration of organs. However, this risks microbial contamination and infection of the recipient if the organ is transplanted. An understanding of perfusate microbial contamination is required to inform infection control procedures and antimicrobial prophylaxis for this technology. METHODS: We modified a liver perfusion machine for long-term use by adding long-term oxygenators and a dialysis filter. Human livers that were not suitable for transplantation were perfused using a red-cell-based perfusate under aseptic and normothermic conditions (36 °C) with a goal of 14 d. Cephazolin was added to the perfusate for antimicrobial prophylaxis. Perfusate and bile were sampled every 72 h for microbial culture. RESULTS: Eighteen partial human livers (9 left lateral segment grafts and 9 extended right grafts) were perfused using our perfusion system. The median survival was 7.2 d. All organs surviving longer than 7 d (9/18) had negative perfusate cultures at 24 and 48 h. Half of the grafts (9/18) became culture-positive by the end of perfusion. Microbial contaminants included Gram-negative ( Pseudomonas species, Proteus mirabilis, Stenotrophomonas maltophilia ) and Gram-positive bacteria ( Staphylococcus epidermidis , Enterococcus faecalis , and Bacillus species) as well as yeast ( Candida albicans ). CONCLUSIONS: Microbial contamination of perfusate is common during long-term perfusion of human livers with both exogenous and endogenous sources. Enhanced infection control practices and review of targeted antimicrobial prophylaxis are likely to be necessary for translation into the clinical arena.


Assuntos
Anti-Infecciosos , Transplante de Fígado , Humanos , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Preservação de Órgãos/métodos , Fígado , Perfusão/efeitos adversos , Perfusão/métodos
5.
Artif Organs ; 48(5): 472-483, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38132848

RESUMO

BACKGROUND: Ex situ machine perfusion facilitates the assessment of livers prior to transplantation. However, currently available markers of liver function poorly predict long-term graft function. Indocyanine green (ICG) is a liver-specific dye which, although common in vivo, has never been comprehensively evaluated for the assessment of graft quality during ex situ machine perfusion. This study aimed to assess the utility of ICG in the ex situ setting. METHODS: Using a customized long-term perfusion system, human livers that were not suitable for transplantation were perfused using a red cell-based perfusate. ICG was delivered into the perfusate on days 0, 1, and 4 to assess ICG clearance (spectrophotometric absorbance at 805 nm) and ICG fluorescence (near-infrared camera). RESULTS: Sixteen partial livers were perfused for a median duration of 172 h (7.2 days). On day 0, the median ICG perfusate disappearance rate (PDR) was 7.5%/min and the median ICG retention at 15 min was 9.9%. Grafts that survived ≥7 days had a significantly higher median ICG PDR on day 0 (14.5%/min vs. 6.5%/min, p = 0.005) but not on days 1 or 4. ICG perfusion demonstrated that long-surviving grafts had a significantly lower median red-value (89.8 vs. 118.6, p = 0.011) and a significantly lower median blue-value (12.9 vs. 22.6, p = 0.045) than short-surviving grafts. CONCLUSION: ICG is a novel marker for the assessment of liver function during ex situ normothermic machine perfusion. ICG PDR and quantitative ICG perfusion can distinguish between long- and short-surviving grafts and demonstrate the utility of ICG in the assessment of graft quality prior to transplant.


Assuntos
Verde de Indocianina , Transplante de Fígado , Humanos , Transplante de Fígado/efeitos adversos , Fígado/cirurgia , Perfusão , Preservação de Órgãos
6.
Hepatol Commun ; 7(4)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36995999

RESUMO

BACKGROUND AND AIMS: Dimeric IgA to monomeric IgA ratio (dIgA ratio) is a biomarker of gut mucosal leakage in liver cirrhosis. We evaluated the diagnostic performance of a novel point-of-care (POC) dIgA ratio test for cirrhosis. METHODS: Plasma samples from people with chronic liver disease were analyzed using the BioPoint POC dIgA ratio antigen immunoassay lateral flow test. Cirrhosis was defined by Fibroscan>12.5 kPa, clinical evidence of cirrhosis or liver histopathology. POC dIgA test diagnostic accuracy was determined in a test cohort using receiver operating characteristic curve analysis; optimal cutoffs for sensitivity and specificity were then applied to a validation cohort. RESULTS: A total of 1478 plasma samples from 866 patients with chronic liver disease were included (test cohort n = 260, validation cohort n = 606). In all, 32% had cirrhosis; 44% Child-Pugh A, 26% Child-Pugh B, and 29% Child-Pugh C. Median POC dIgA ratio was higher in cirrhosis (0.9) compared with no cirrhosis (0.4, p < 0.001), and in Child-Pugh class B/C compared with A cirrhosis (1.4 Child-Pugh B/C vs. 0.6 Child-Pugh A, p < 0.001). POC dIgA ratio test had good diagnostic accuracy for liver cirrhosis in the test cohort (area under the receiver operating characteristic curve=0.80); a dIgA ratio cutoff of 0.6 had a sensitivity of 74% and specificity of 86%. POC dIgA test accuracy was moderate in the validation cohort (area under the receiver operating characteristic curve=0.75; positive predictive value 64%, negative predictive value 83%). Using a dual cutoff approach, 79% of cirrhosis cases were correctly diagnosed and further testing was avoided in 57%. CONCLUSIONS: POC dIgA ratio test had moderate accuracy for cirrhosis. Further studies evaluating the accuracy of POC dIgA ratio testing for cirrhosis screening are warranted.


Assuntos
Cirrose Hepática , Polímeros , Humanos , Projetos Piloto , Estudos de Coortes , Testes Imediatos , Imunoglobulina A
8.
JCI Insight ; 7(21)2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36173679

RESUMO

Immune-related adverse events represent a major hurdle to the success of immunotherapy. The immunological mechanisms underlying their development and relation to antitumor responses are poorly understood. By examining both systemic and tissue-specific immune changes induced by combination anti-CTLA-4 and anti-PD-1 immunotherapy, we found distinct repertoire changes in patients who developed moderate-severe colitis, irrespective of their antitumor response to therapy. The proportion of circulating monocytes were significantly increased at baseline in patients who subsequently developed colitis compared with patients who did not develop colitis, and biopsies from patients with colitis showed monocytic infiltration of both endoscopically and histopathologically normal and inflamed regions of colon. The magnitude of systemic expansion of T cells following commencement of immunotherapy was also greater in patients who developed colitis. Importantly, we show expansion of specific T cell subsets within inflamed regions of the colon, including tissue-resident memory CD8+ T cells and Th1 CD4+ T cells in patients who developed colitis. Our data also suggest that CD8+ T cell expansion was locally induced, while Th1 cell expansion was systemic. Together, our data show that exaggerated innate and T cell responses to combination immunotherapy synergize to propel colitis in susceptible patients.


Assuntos
Colite , Receptor de Morte Celular Programada 1 , Humanos , Linfócitos T CD8-Positivos , Imunoterapia/efeitos adversos , Colite/induzido quimicamente , Colite/terapia , Fatores Imunológicos , Imunidade Inata
9.
Biofactors ; 48(2): 329-341, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34665899

RESUMO

Gut dysbiosis is an important modifier of pathologies including cardiovascular disease but our understanding of the role of individual microbes is limited. Here, we have used transplantation of mouse microbiota into microbiota-deficient zebrafish larvae to study the interaction between members of a mammalian high fat diet-associated gut microbiota with a lipid rich diet challenge in a tractable model species. We find zebrafish larvae are more susceptible to hyperlipidaemia when exposed to the mouse high fat-diet-associated microbiota and that this effect can be driven by two individual bacterial species fractionated from the mouse high fat-diet-associated microbiota. We find Stenotrophomonas maltophilia increases the hyperlipidaemic potential of chicken egg yolk to zebrafish larvae independent of direct interaction between S. maltophilia and the zebrafish host. Colonization by live, or exposure to heat-killed, Enterococcus faecalis accelerates hyperlipidaemia via host MyD88 signaling. The hyperlipidaemic effect is replicated by exposure to the Gram-positive toll-like receptor agonists peptidoglycan and lipoteichoic acid in a MyD88-dependent manner. In this work, we demonstrate the applicability of zebrafish as a tractable host for the identification of gut microbes that can induce conditional host phenotypes via microbiota transplantation and subsequent challenge with a high fat diet.


Assuntos
Hiperlipidemias , Microbiota , Aceleração , Animais , Parede Celular , Dieta Hiperlipídica/efeitos adversos , Hiperlipidemias/genética , Larva , Mamíferos , Camundongos , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/farmacologia , Peixe-Zebra/genética , Peixe-Zebra/microbiologia , Proteínas de Peixe-Zebra/farmacologia
10.
Liver Transpl ; 28(2): 236-246, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34624175

RESUMO

Introduction of universal access to direct-acting antiviral (DAA) therapy for hepatitis C virus (HCV) in Australia and New Zealand on March 1st , 2016, has had a major impact on the number of people with chronic HCV infection, but the impact on liver transplantation rates is unknown. We conducted a retrospective registry study including all adult liver transplantations from the Australia and New Zealand Liver and Intestinal Liver Transplant Registry (ANZLITR) data set. Interrupted time series analysis determined the impact of DAAs in 2016 on the number of HCV liver transplantations per year. Cox regression analysis was used to determine the impact of DAAs on post-liver transplantation survival. Between January 1, 1990, and December 31, 2019 5318 adult liver transplantations were performed, and 29% (1531) were for HCV infection. Prior to the introduction of DAAs, there was a mean increase of 3.5 adult liver transplantations performed for HCV per annum, but between 2016 and 2019 there was a mean decrease of 7.9 adult liver transplantations per annum (P < 0.001). Similarly, the proportion of liver transplantations performed for HCV increased from 9% (1990) to 33% in 2016 and then fell to 23% in 2019 (P < 0.001). The number and proportion of patients with HCV added to the liver transplantation waiting list also fell in 2016 (P < 0.001) when compared with other indications. The introduction of DAAs was associated with a 31% reduction in death after liver transplantation, adjusted for age at transplant and hepatocellular carcinoma (HCC; hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.48-0.99; P = 0.047). The number of adult liver transplantations performed for HCV-related liver cirrhosis and HCC has reduced since the introduction of universal access to DAAs in 2016 in Australia and New Zealand.


Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Hepatite C , Neoplasias Hepáticas , Transplante de Fígado , Adulto , Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/cirurgia , Hepacivirus , Hepatite C/complicações , Hepatite C/tratamento farmacológico , Hepatite C/epidemiologia , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/epidemiologia , Humanos , Transplante de Fígado/efeitos adversos , Nova Zelândia/epidemiologia , Estudos Retrospectivos
11.
Am J Transplant ; 22(3): 909-926, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34780106

RESUMO

To extend previous molecular analyses of rejection in liver transplant biopsies in the INTERLIVER study (ClinicalTrials.gov #NCT03193151), the present study aimed to define the gene expression selective for parenchymal injury, fibrosis, and steatohepatitis. We analyzed genome-wide microarray measurements from 337 liver transplant biopsies from 13 centers. We examined expression of genes previously annotated as increased in injury and fibrosis using principal component analysis (PCA). PC1 reflected parenchymal injury and related inflammation in the early posttransplant period, slowly regressing over many months. PC2 separated early injury from late fibrosis. Positive PC3 identified a distinct mildly inflamed state correlating with histologic steatohepatitis. Injury PCs correlated with liver function and histologic abnormalities. A classifier trained on histologic steatohepatitis predicted histologic steatohepatitis with cross-validated AUC = 0.83, and was associated with pathways reflecting metabolic abnormalities distinct from fibrosis. PC2 predicted histologic fibrosis (AUC = 0.80), as did a molecular fibrosis classifier (AUC = 0.74). The fibrosis classifier correlated with matrix remodeling pathways with minimal overlap with those selective for steatohepatitis, although some biopsies had both. Genome-wide assessment of liver transplant biopsies can not only detect molecular changes induced by rejection but also those correlating with parenchymal injury, steatohepatitis, and fibrosis, offering potential insights into disease mechanisms for primary diseases.


Assuntos
Transplante de Fígado , Fígado , Biópsia , Fígado Gorduroso , Fibrose , Rejeição de Enxerto , Humanos , Fígado/patologia , Transplante de Fígado/efeitos adversos , Fenótipo
12.
Drug Alcohol Rev ; 41(3): 706-714, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34839561

RESUMO

INTRODUCTION: Opioid agonist treatment (OAT) clinics play a key role in achieving elimination of hepatitis C virus (HCV) globally. Previous research has identified barriers to HCV treatment uptake in OAT clinics; however, most studies were conducted prior to the introduction of direct-acting antiviral treatments (DAA). It remains unclear whether progress has been made in responding to barriers and what challenges persist in this setting. METHODS: Semi-structured in-depth interviews were conducted with staff (n = 20) and clients (n = 15) in two OAT clinics in Sydney, Australia. Interviews were transcribed verbatim and analysed using constant comparative methods. RESULTS: Despite progress in integrating hepatitis C care in the clinics, competing priorities, concerns about side-effects, distrust of staff, health problems and difficulties accessing testing and medication persisted as key reasons why clients had not initiated treatment. Most clients preferred to postpone treatment and focus on other priorities and some highlighted lack of medical evidence for urgent treatment. Pressure on services to achieve elimination targets within set time frames was a primary driver of repeated offers of treatment by staff and the framing of clients' preferences for postponing treatment, as a barrier. DISCUSSION AND CONCLUSION: Current timelines for HCV elimination targets may have galvanised services into action but may have also created tensions at the coalface due to disparities between staff and clients' priorities. The involvement of peer workers and mechanisms to ensure continued follow up with clients about DAA treatments is required. Public health timelines for HCV elimination need to be informed by affected communities' priorities.


Assuntos
Hepatite C Crônica , Hepatite C , Abuso de Substâncias por Via Intravenosa , Analgésicos Opioides/uso terapêutico , Antivirais/uso terapêutico , Austrália , Hepatite C/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Humanos
14.
Transplant Direct ; 8(8): e1345, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37077731

RESUMO

Prevalence of concurrent liver diseases among liver transplant recipients and impact on posttransplant outcomes are unknown. Methods: This retrospective study included adult liver transplants between January 1' 1985' and December 31' 2019' from the Australian and New Zealand Liver and Intestinal Transplant Registry. Up to 4 liver disease causes were recorded for each transplant; concurrent liver diseases were defined as >1 liver disease indication for transplantation, excluding hepatocellular carcinoma. Impact on posttransplant survival was determined using Cox regression. Results: A total of 840 (15%) of 5101 adult liver transplant recipients had concurrent liver diseases. Recipients with concurrent liver diseases were more likely male (78% versus 64%) and older (mean age 52 versus 50 y). A higher proportion of liver transplants for hepatitis B (12% versus 6%), hepatitis C (33% versus 20%), alcohol liver disease (23% versus 13%), and metabolic-associated fatty liver disease (11% versus 8%, all P < 0.001) were identified when all indications were included than with primary diagnosis only. The number and proportion of liver transplants performed for concurrent liver diseases have increased from 8 (6%) during Era 1 (1985-1989) to 302 (20%) during Era 7 (2015-2019; P < 0.001). Concurrent liver diseases were not associated with increased posttransplant mortality (adjusted hazard ratio, 0.98, 95% confidence interval, 0.84-1.14). Conclusions: Concurrent liver diseases are increasing among adult liver transplant recipients in Australia and New Zealand; however, they do not appear to impact posttransplant survival. Reporting all liver disease causes in the transplant registry reports provides more accurate estimates of liver disease burden.

17.
J Viral Hepat ; 28(1): 121-128, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32869904

RESUMO

The World Health Organization has set ambitious viral hepatitis elimination targets; however, difficulties in identifying and engaging patients remain. The emergency visit is an opportunity for enhanced linkage to care (LTC). We assessed the effectiveness of an automated Emergency Department (ED) screening service in identifying patients with hepatitis C (HCV) and achieving LTC. A retrospective evaluation was undertaken, analysing the first 5000 patients screened through an automatic Australian service termed 'Screening Emergency Admissions at Risk of Chronic Hepatitis' (SEARCH). Screening was performed for those recommended in the Australian national testing policy, specifically overseas born (OB) and Aboriginal or Torres Strait Islanders (ATSI). Healthcare worker education, patient information materials and opt-out informed consent were used to test sera already collected for biochemistry assays. 5000 of 5801 (86.2%) consecutive eligible patients were screened (OB: 4778, ATSI: 222) from 14 093 ED presentations. HCV antibody was positive in 181 patients (3.6%); 51 (1.0%) were HCV RNA positive. Of 51 HCV RNA-positive patients, 12 were new diagnoses, 32 were 're-diagnoses' (aware but lost to follow-up [LTFU]), and 7 were previously known but treatment contraindicated. LTC was successful in 38 viraemic patients (7 deceased, 4 LTFU, 1 treatment ineligible and 1 declined). Of RNA-negative patients, 75 were previously treated and 49 had presumed spontaneous clearance. Opt-out consent was acceptable to all patients and staff involved. ED screening can lead to additional diagnosing and 're-diagnosing' of HCV, with high rates of LTC. Opt-out consent and automation removed major obstacles to testing.


Assuntos
Hepatite C Crônica , Hepatite C , Austrália/epidemiologia , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Hepatite C Crônica/diagnóstico , Hepatite C Crônica/epidemiologia , Humanos , Programas de Rastreamento , Estudos Retrospectivos
18.
Med J Aust ; 213(10): 464-470, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33015834

RESUMO

OBJECTIVE: To assess long term graft and patient survival after donor liver retransplantation in children in Australia and New Zealand during 1986-2017; to determine the factors that influence survival. DESIGN: Retrospective cohort analysis (registry data). SETTING, PARTICIPANTS: Australia and New Zealand Liver Transplant Registry data for all liver retransplantations in children (under 18 years of age), 1986-2017, in all four paediatric and six adult liver transplantation centres in the two countries. MAIN OUTCOME MEASURES: Graft and patient survival at one, 5, 10 and 15 years. RESULTS: 142 liver retransplantations were undertaken in children (59 during 1986-2000, 83 during 2001-2017). Kaplan-Meier survival analysis indicated that survival was significantly greater during 2001-2017 than 1986-2000 (P < 0.001). During 2001-2017, graft survival one year after retransplantation was 84%, at 5 years 75%, at 10 years 70%, and at 15 years 54%; patient survival was 89% at one year, 87% at 5 years, 87% at 10 years, and 71% at 15 years. Median time between transplantations was 0.2 years (IQR, 0.03-1.4 years) during 1986-2000, and 1.8 years (IQR, 0.1-6.8 years) during 2001-2017 (P = 0.002). The proportion of graft failures that involved split grafts was larger during 2001-2017 (35 of 83, 42%) than 1986-2000 (10 of 59, 17%). Graft type, cause of graft failure, and number of transplants did not influence survival following retransplantation. CONCLUSION: Survival for children following retransplantation is excellent. Graft survival is similar for split and whole grafts. Children on the liver waiting list requiring retransplantation should have the same access to donor grafts as children requiring a first transplant.


Assuntos
Transplante de Fígado/mortalidade , Reoperação , Adulto , Austrália/epidemiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Lactente , Estimativa de Kaplan-Meier , Transplante de Fígado/métodos , Masculino , Nova Zelândia/epidemiologia , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Doadores de Tecidos , Resultado do Tratamento , Listas de Espera
19.
Sci Transl Med ; 12(560)2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32908003

RESUMO

Recent clinical successes in gene therapy applications have intensified interest in using adeno-associated viruses (AAVs) as vectors for therapeutic gene delivery. Although prototypical AAV2 shows robust in vitro transduction of human hepatocyte-derived cell lines, it has not translated into an effective vector for liver-directed gene therapy in vivo. This is consistent with observations made in Fah-/-/Rag2-/-/Il2rg-/- (FRG) mice with humanized livers, showing that AAV2 functions poorly in this xenograft model. Here, we derived naturally hepatotropic AAV capsid sequences from primary human liver samples. We demonstrated that capsid mutations, likely acquired as an unintentional consequence of tissue culture propagation, attenuated the intrinsic human hepatic tropism of natural AAV2 and related human liver AAV isolates. These mutations resulted in amino acid changes that increased binding to heparan sulfate proteoglycan (HSPG), which has been regarded as the primary cellular receptor mediating AAV2 infection of human hepatocytes. Propagation of natural AAV variants in vitro showed tissue culture adaptation with resulting loss of tropism for human hepatocytes. In vivo readaptation of the prototypical AAV2 in FRG mice with a humanized liver resulted in restoration of the intrinsic hepatic tropism of AAV2 through decreased binding to HSPG. Our results challenge the notion that high affinity for HSPG is essential for AAV2 entry into human hepatocytes and suggest that natural AAV capsids of human liver origin are likely to be more effective for liver-targeted gene therapy applications than culture-adapted AAV2.


Assuntos
Dependovirus , Vetores Genéticos , Animais , Capsídeo , Dependovirus/genética , Humanos , Fígado , Camundongos , Transdução Genética , Tropismo
20.
Am J Transplant ; 20(8): 2156-2172, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32090446

RESUMO

Molecular diagnosis of rejection is emerging in kidney, heart, and lung transplant biopsies and could offer insights for liver transplant biopsies. We measured gene expression by microarrays in 235 liver transplant biopsies from 10 centers. Unsupervised archetypal analysis based on expression of previously annotated rejection-related transcripts identified 4 groups: normal "R1normal " (N = 129), T cell-mediated rejection (TCMR) "R2TCMR " (N = 37), early injury "R3injury " (N = 61), and fibrosis "R4late " (N = 8). Groups differed in median time posttransplant, for example, R3injury 99 days vs R4late 3117 days. R2TCMR biopsies expressed typical TCMR-related transcripts, for example, intense IFNG-induced effects. R3injury displayed increased expression of parenchymal injury transcripts (eg, hypoxia-inducible factor EGLN1). R4late biopsies showed immunoglobulin transcripts and injury-related transcripts. R2TCMR correlated with histologic rejection although with many discrepancies, and R4late with fibrosis. R2TCMR , R3injury , and R4late correlated with liver function abnormalities. Supervised classifiers trained on histologic rejection showed less agreement with histology than unsupervised R2TCMR scores. No confirmed cases of clinical antibody-mediated rejection (ABMR) were present in the population, and strategies that previously revealed ABMR in kidney and heart transplants failed to reveal a liver ABMR phenotype. In conclusion, molecular analysis of liver transplant biopsies detects rejection, has the potential to resolve ambiguities, and could assist with immunosuppressive management.


Assuntos
Transplante de Coração , Transplante de Rim , Transplante de Fígado , Biópsia , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/genética , Transplante de Fígado/efeitos adversos
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