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BACKGROUND AND AIMS: Observational studies suggest a beneficial effect of continuous terlipressin infusion (CTI) on ascites and sarcopenia in decompensated cirrhosis with portal hypertension. APPROACH AND RESULTS: This single-center, prospective, cross-over study randomized 30 patients with cirrhosis, ascites, and sarcopenia to commence on 12 weeks of home CTI or 12 weeks of observation prior to cross-over. The co-primary outcomes were change in handgrip strength and paracentesis volume. Secondary outcomes included quality of life, sarcopenia measures, renal function, safety, and hospitalization. The median age of participants was 62 years (IQR: 57-64), the median Model for End-Stage Liver Disease-Sodium was 16 (12.3-20.8), and 22 (73%) were male. Handgrip strength increased by a mean adjusted difference (MAD) of 3.09 kg (95% CI: 1.11-5.08 kg) between CTI and observation ( p =0.006); an 11.8% increase from baseline. The total volume of ascites drained decreased by a MAD of 11.39L (2.99-19.85, p =0.01), with 1.75 fewer episodes of paracentesis (0.925-2.59, p <0.001) on CTI. Serum creatinine decreased, urinary sodium excretion increased, and quality of life was significantly higher on CTI (all p <0.001), with an increase in Chronic Liver Disease Questionnaire score of 0.41 points (0.23-0.59). There were 7 minor line-related complications but no cardiac events or pulmonary edema. CONCLUSIONS: This novel study demonstrates a significant increase in handgrip strength, reduction in paracentesis volume, and improved quality of life in patients with decompensated cirrhosis treated with continuous terlipressin infusion. These findings provide a strong rationale for the use of ambulatory CTI in appropriately selected patients with cirrhosis.
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Ascite , Estudos Cross-Over , Força da Mão , Cirrose Hepática , Terlipressina , Humanos , Masculino , Pessoa de Meia-Idade , Ascite/tratamento farmacológico , Ascite/etiologia , Terlipressina/administração & dosagem , Estudos Prospectivos , Feminino , Cirrose Hepática/complicações , Cirrose Hepática/tratamento farmacológico , Infusões Intravenosas , Vasoconstritores/administração & dosagem , Sarcopenia/prevenção & controle , Sarcopenia/tratamento farmacológico , Sarcopenia/etiologia , Qualidade de Vida , Hipertensão Portal/tratamento farmacológico , IdosoRESUMO
Erythropoietic protoporphyria (EPP) is an inherited metabolic disorder of heme synthesis resulting from overproduction of protoporphyrin IX (PPIX), which can lead to progressive liver disease characterized by recurrent EPP crises and end-stage liver disease. We used the Australian Transplant Registry to identify 5 patients referred for liver transplantation between 2008 and 2017. A total of 4 patients had EPP secondary to ferrochelatase deficiency, and 1 patient had X-linked EPP. No patient had follow-up with a specialist prior to the diagnosis of progressive liver disease. There were 3 patients who underwent orthotopic liver transplantation, whereas 2 died while on the transplant waiting list. Parenteral PPIX-lowering therapy was used in 4 patients and was effective in 3 patients, although 2 of these had rebound porphyria and worsening liver function following a decrease in the intensity of therapy. Early disease recurrence in the allograft following transplantation occurred in 2 patients requiring red cell exchange (RCE) to successfully attain and maintain low PPIX levels, but RCE was associated with hemosiderosis in 1 patient. Allogeneic stem cell transplantation (AlloSCT) was performed in 2 patients. One failed engraftment twice, whereas the second rejected the first graft but achieved full donor chimerism with a second graft and increased immunosuppression. In conclusion, our observations suggest that progressive liver disease needs parenteral PPIX-lowering treatment with the intensity adjusted to achieve a target Erc-PPIX level. Because EPP liver disease is universally recurrent, AlloSCT should be considered in all patients with adequate immunosuppression to facilitate engraftment. RCE appears to be effective for recurrent EPP liver disease but is associated with an increased risk of iron overload.
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Doença Hepática Terminal/terapia , Rejeição de Enxerto/epidemiologia , Transplante de Fígado , Protoporfiria Eritropoética/patologia , Transplante de Células-Tronco , Listas de Espera/mortalidade , Adolescente , Adulto , Aloenxertos/patologia , Progressão da Doença , Doença Hepática Terminal/mortalidade , Doença Hepática Terminal/patologia , Feminino , Rejeição de Enxerto/patologia , Humanos , Lactente , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Protoporfiria Eritropoética/mortalidade , Protoporfiria Eritropoética/terapia , Recidiva , Sistema de Registros/estatística & dados numéricos , Transplante Homólogo , Adulto JovemRESUMO
Balancing immunosuppression after liver transplant is difficult, with clinical events common. We investigate whether a novel immune biomarker based on a laboratory platform with widespread availability that measures interferon γ (IFNγ) after stimulation with a lyophilized ball containing an adaptive and innate immune stimulant can predict events following transplantation. A total of 75 adult transplant recipients were prospectively monitored in a blinded, observational study; 55/75 (73.3%) patients experienced a total of 89 clinical events. Most events occurred within the first month. Low week 1 results were significantly associated with risk of early infection (area under the receiver operating characteristic curve [AUROC], 0.74; P = 0.008). IFNγ ≤ 1.30 IU/mL (likelihood ratio positive, 1.93; sensitivity, 71.4%; specificity, 63.0%) was associated with the highest risk for infection with minimal rejection risk. Nearly half the cohort (27/60, 45.0%) expressed IFNγ ≤ 1.30 IU/mL. Moreover, an elevated week 1 result was significantly associated with the risk of rejection within the first month after transplant (AUROC, 0.77; P = 0.002), but no episodes of infection. On multivariate logistic regression, IFNγ ≥ 4.49 IU/mL (odds ratio, 4.75) may be an independent predictor of rejection (P = 0.05). In conclusion, low IFNγ suggesting oversuppression is associated with infections, whereas high IFNγ indicating undersuppression is associated with rejection. This assay offers the potential to allow individualization and optimization of immunosuppression that could fundamentally alter the way patients are managed following transplantation. Liver Transplantation 23 487-497 2017 AASLD.
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Doenças Transmissíveis/sangue , Rejeição de Enxerto/sangue , Terapia de Imunossupressão/efeitos adversos , Interferon gama/sangue , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/sangue , Medicina de Precisão/métodos , Adulto , Idoso , Área Sob a Curva , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/imunologia , Doença Hepática Terminal/cirurgia , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Humanos , Terapia de Imunossupressão/métodos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/imunologia , Curva ROC , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Adulto JovemRESUMO
Cytomegalovirus (CMV) can reactivate following liver transplantation. Management of patients currently considered low risk based on pretransplant serology remains contentious, with universal prophylaxis and preemptive strategies suffering from significant deficiencies. We hypothesized that a CMV-specific T cell assay performed early after transplant as part of a preemptive strategy could better stratify "low-risk" (recipient seropositive) patients. We conducted a prospective, blinded, observational study in 75 adult recipients. QuantiFERON-cytomegalovirus was performed both before and at multiple times after transplant. Low-risk patients (n = 58) were monitored as per unit protocol and treatment was commenced if CMV > 1000 copies/mL (DNAemia). Twenty patients needed antiviral treatment for other reasons and were censored (mainly for rejection or herpes simplex virus infection); 19/38 (50%) of the remaining low-risk patients developed DNAemia at mean 34.6 days after transplant. A week 2 result of <0.1 IU/mL was significantly associated with risk of subsequent DNAemia (hazard ratio [HR], 6.9; P = 0.002). The positive predictive value of 80% suggests these patients are inappropriately labeled low risk and are actually at high likelihood of CMV reactivation. A secondary cutoff of <0.2 IU/mL was associated with moderate risk (HR, 2.8; P = 0.01). In conclusion, a protocol based on a single early CMV-specific T cell based assay would offer improved risk stratification and individualization of patient management after transplant. This could offer improved drug and service utilization and potentially result in significant improvements over both currently used protocols to manage supposedly low-risk patients.
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Infecções por Citomegalovirus/prevenção & controle , Transplante de Fígado , Complicações Pós-Operatórias/prevenção & controle , Adulto , Infecções por Citomegalovirus/imunologia , Humanos , Interferon gama/sangue , Pessoa de Meia-Idade , Complicações Pós-Operatórias/imunologia , Estudos Prospectivos , Medição de RiscoRESUMO
BACKGROUND: Pre-transplant muscle wasting measured by computed tomography has been associated with adverse clinical outcomes after liver transplantation including increased rates of sepsis and hospitalisation days. Upper limb lean mass (LM) measured by dual-energy X-ray absorptiometry (DEXA) was recently identified as a novel predictor of sarcopenia-associated mortality in men waitlisted for transplantation. AIM: To investigate the use of DEXA LM in predicting gender-stratified early post-transplant outcomes. METHODS: Liver transplant recipients who underwent pre-transplant DEXA body composition imaging between 2002 and 2017 were included. Endpoints included post-transplant mortality and graft failure, bacterial infections, acute cellular rejection (ACR) and intensive care and total hospital length of stay. RESULTS: Four hundred and sixty-nine patients met inclusion criteria of which 338 were male (72%). Median age was 55.0 years (interquartile range 47.4, 59.7) and model for end-stage liver disease (MELD) score 16. Median time from assessment to transplantation was 7 mo (3.5, 12). Upper limb LM was inversely associated with bacterial infections at 180 d post-transplant (hazard ratio = 0.42; 95% confidence interval: 0.20-0.89; P = 0.024) in males only. There was a negative correlation between upper limb LM and intensive care (τb = -0.090, P = 0.015) and total hospital length of stay (τb = -0.10, P = 0.0078) in men. In women, neither MELD nor body composition parameters were associated with post-transplant adverse outcomes or increased length of stay. Body composition parameters, MELD and age were not associated with 90-d mortality or graft failure in either gender. There were no significant predictors of early ACR. CONCLUSION: Sarcopenia is an independent and potentially modifiable predictor of increased post-transplant bacterial infections and hospital length of stay in men with cirrhosis. DEXA upper limb LM provides a novel measure of muscle wasting that has prognostic value in this cohort. The lack of association in women requires further investigation.
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BACKGROUND/AIM: Therapeutic options are limited for patients with hepatorenal syndrome (HRS), diuretic refractory ascites and hepatic hydrothorax who are awaiting liver transplant. We assessed the safety and efficacy of continuous terlipressin infusion (CTI) for treating these conditions in an outpatient setting. METHOD: All patients treated with CTI from May 2013 through March 2018 at our institution were initiated in-hospital on bolus dose terlipressin therapy for 24-72 h prior to commencing CTI for home therapy. Daily home visits for clinical assessment and medication administration were provided. Adverse events, effects of treatment on renal function, model for end-stage liver disease (MELD) score, and paracentesis/thoracentesis requirements were assessed. RESULTS: Twenty-three patients were included (HRS = 17; refractory ascites = 4; refractory hepatic hydrothorax = 2). Median (range) duration of outpatient CTI was 50 (1-437) days with a total of 2482 patient days of treatment. Fourteen patients (60.9%) received a liver transplant; of whom 13 (92.9%) were alive at the end of the study period. There were no cardiac or ischemic complications and no serious adverse events reported. In patients with HRS, median serum creatinine significantly decreased from 202.0 µmol/L at baseline to 125.5 µmol/L at day 14 of CTI (P = 0.0003) and remained stable thereafter. Median MELD score decreased from 22.5 to 19.0 at end of CTI (P = 0.008). Median frequency of paracentesis/thoracentesis was 4 per month prior to CTI versus 1.52 during treatment. CONCLUSION: Transplant-eligible and otherwise stable patients can be managed with CTI at home for an extended duration under supervision without adverse consequences.
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Doença Hepática Terminal , Síndrome Hepatorrenal , Hidrotórax , Ascite/tratamento farmacológico , Ascite/etiologia , Doença Hepática Terminal/complicações , Síndrome Hepatorrenal/tratamento farmacológico , Síndrome Hepatorrenal/etiologia , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/tratamento farmacológico , Lipressina/efeitos adversos , Pacientes Ambulatoriais , Índice de Gravidade de Doença , Terlipressina/efeitos adversos , Resultado do Tratamento , Vasoconstritores/uso terapêuticoAssuntos
Ascite/tratamento farmacológico , Lipressina/análogos & derivados , Vasoconstritores/uso terapêutico , Assistência Ambulatorial , Ascite/terapia , Cateterismo Periférico , Humanos , Infusões Intravenosas , Lipressina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Paracentese , TerlipressinaRESUMO
Three decades after the first intestinal transplant was performed in humans, this life-saving procedure has come of age and now offers hope of long-term survival in a small group of patients with life-threatening complications of intestinal failure and parenteral nutrition. Success rates have greatly improved, largely through advances in immunosuppression protocols, improved surgical technique and postoperative care, and accumulated experience. Management of the intestinal transplant recipient entails careful surveillance, prevention, and treatment of rejection and infection, as well as optimization of feeding and nutrition. With this approach, survival and quality of life are demonstrably improved, such that intestinal transplantation is now an established and accepted procedure for this very select group of highly-complex patients.
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Enteropatias/cirurgia , Intestinos/transplante , Transplante de Órgãos/tendências , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto , Humanos , Terapia de Imunossupressão/tendências , Transplante de Órgãos/efeitos adversos , Nutrição Parenteral no Domicílio/efeitos adversos , Qualidade de Vida , Resultado do TratamentoRESUMO
BACKGROUND AND AIMS: Toll-like receptor (TLR) signaling is a crucial step in initiating adaptive immune responses. In addition to recognizing endotoxin, TLR4 also recognizes endogenous ligands ('damage-associated structures'), which are released into the circulation in the peri-transplantation period. TLR2 to a lesser extent also recognizes these endogenous ligands. Multiple studies involving solid organ transplants demonstrate a clear association between TLR4 and allograft rejection. In the present study we assessed whether an association exists between TLR4 and TLR2-dependent responses and acute liver allograft rejection. METHODS: The sample included 26 liver transplant recipients. Blood was taken pre-transplant and at multiple points over the first 14 days post-transplant. Monocytes were stimulated with TLR4 and TLR2 ligands, lipopolysaccharide and Pam-3-Cys, respectively. Monocyte TLR expression was determined using flow cytometry; enzyme-linked immunosorbent assays measured tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production. RESULTS: Nine (34.6%) patients experienced rejection. No differences existed in age, sex, disease or immunosuppression between rejectors and non-rejectors. Baseline TLR4 expression was significantly higher in rejectors (1.36 vs 1.02, P=0.01). There was no difference in TLR2 expression. In rejectors, baseline TLR4- and TLR2-dependent production of TNF-α and IL-6 was also significantly increased. Post-transplant, the two groups differed with regard to TLR4-dependent TNF-α production, with rejectors demonstrating progressive downregulation over the first week. CONCLUSIONS: Prior to liver transplantation, patients who subsequently experience rejection demonstrate robust TLR4-dependent immune responses, which are not seen in those who do not reject. This supports the theory that damage-associated structures signaling through TLR4 may be responsible for the early activation of alloimmune T-cells, favoring allograft rejection.
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Rejeição de Enxerto/imunologia , Imunidade Inata , Transplante de Fígado/imunologia , Monócitos/imunologia , Transdução de Sinais , Receptor 4 Toll-Like/metabolismo , Doença Aguda , Adulto , Células Cultivadas , Cisteína/análogos & derivados , Cisteína/farmacologia , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Imunidade Inata/efeitos dos fármacos , Interleucina-6/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Lipoproteínas/farmacologia , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Projetos Piloto , Estudos Prospectivos , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Receptor 2 Toll-Like/agonistas , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/agonistas , Transplante Homólogo , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima , VitóriaAssuntos
Artralgia/induzido quimicamente , Azatioprina/efeitos adversos , Eritema Nodoso/diagnóstico , Febre/induzido quimicamente , Hepatite Autoimune/tratamento farmacológico , Imunossupressores/efeitos adversos , Idoso , Hipersensibilidade a Drogas/diagnóstico , Hipersensibilidade a Drogas/etiologia , Eritema Nodoso/induzido quimicamente , Exantema/induzido quimicamente , Humanos , Masculino , Suspensão de TratamentoRESUMO
BACKGROUND AND AIMS: Sarcopenia, defined as loss of muscle mass, strength and function, is associated with adverse clinical outcomes in patients with cirrhosis. Despite improved understanding of the multifaceted pathogenesis, there are few established therapies to treat or prevent muscle loss in this population. This narrative review examines the available literature investigating the role of nutraceuticals for the prevention or treatment of muscle wasting in chronic liver disease. METHODS: A comprehensive search or Medline and PubMED databases was conducted. Reference lists were screened to identify additional articles. RESULTS: A number of nutritional supplements and vitamins target the specific metabolic derangements that contribute to sarcopenia in cirrhosis including altered amino acid metabolism, hyperammonaemia and inflammation. Branched chain amino acid (BCAA) supplementation has proposed anabolic effects through dual pathways of enhanced ammonia clearance and stimulation of muscle protein synthesis. l-carnitine also has multimodal effects on muscle and shows promise as a therapy for muscle loss through anti-inflammatory, antioxidant and ammonia lowering properties. Other nutraceuticals including l-ornithine l-aspartate, omega-3 polyunsaturated fatty acids and zinc and vitamin D supplementation, may similarly have positive effects on muscle homeostasis, however further evidence to support their use in cirrhotic populations is required. CONCLUSION: Nutraceuticals offer a promising and likely safe adjunct to standard care for sarcopenia in cirrhosis. While there is most evidence to support the use of BCAA and l-carnitine supplementation, further well-designed clinical trials are needed to elucidate their efficacy as a therapy for muscle loss in this population.
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Hepatopatias , Sarcopenia , Aminoácidos de Cadeia Ramificada , Suplementos Nutricionais , Humanos , Músculo Esquelético/patologia , Sarcopenia/tratamento farmacológicoRESUMO
Upper gastrointestinal bleeding from oesophageal or gastric varices is an important medical condition in patients with portal hypertension. Despite the emergence of a number of novel endoscopic and radiologic therapies for oesophagogastric varices, controversy exists regarding the indication, timing and modality of therapy. The aim of this review is to provide a concise and practical evidence-based overview of these issues.
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BACKGROUND: Management of single small hepatocellular carcinoma (HCC) is straightforward with curative outcomes achieved by locoregional therapy or resection. Liver transplantation is often considered for multiple small or single large HCC. Management of two small HCC whether presenting synchronously or sequentially is less clear. AIM: To define the outcomes of patients presenting with two small HCC. METHODS: Retrospective review of HCC databases from multiple institutions of patients with either two synchronous or sequential HCC ≤ 3 cm between January 2000 and March 2018. Primary outcomes were overall survival (OS) and transplant-free survival (TFS). RESULTS: 104 patients were identified (male n = 89). Median age was 63 years (interquartile range 58-67.75) and the most common aetiology of liver disease was hepatitis C (40.4%). 59 (56.7%) had synchronous HCC and 45 (43.3%) had sequential. 36 patients died (34.6%) and 25 were transplanted (24.0%). 1, 3 and 5-year OS was 93.0%, 66.1% and 62.3% and 5-year post-transplant survival was 95.8%. 1, 3 and 5-year TFS was 82.1%, 45.85% and 37.8%. When synchronous and sequential groups were compared, OS (1,3 and 5 year synchronous 91.3%, 63.8%, 61.1%, sequential 95.3%, 69.5%, 64.6%, P = 0.41) was similar but TFS was higher in the sequential group (1,3 and 5 year synchronous 68.5%, 37.3% and 29.7%, sequential 93.2%, 56.6%, 48.5%, P = 0.02) though this difference did not remain during multivariate analysis. CONCLUSION: TFS in patients presenting with two HCC ≤ 3 cm is poor regardless of the timing of the second tumor. All patients presenting with two small HCC should be considered for transplantation.
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BACKGROUND & AIMS: Toll-like receptors (TLRs) are critical to innate immune responses. TLR4 recognises Gram-negative bacteria, whilst TLR2 recognises Gram-positive. We examined TLR expression and function in cirrhosis, and whether this is affected by antibiotic therapy. METHODS: Sixty-four subjects were included (23 controls and 41 Child-Pugh C cirrhotic patients). Thirty patients were taking norfloxacin or trimethoprim-sulfamethoxazole as prophylaxis against bacterial peritonitis and 11 were not. In a second study, 8 patients were examined before and after commencement of antibiotics. Monocyte expression of TLR2 and 4 was determined by flow cytometry. Monocytes from the patients with paired samples were stimulated using TLR ligands and TNF-alpha production measured. RESULTS: Patients not taking antibiotics had significantly decreased TLR4 expression compared with controls (0.74 vs. 1.0, p=0.009) and patients receiving antibiotics (0.74 vs. 0.98, p=0.02). There were no differences with regard to TLR2. In the patients with paired samples, TLR4 expression increased (0.74-1.49, p=0.002) following antibiotic use, whilst again, there was no change in TLR2 expression (0.99 vs. 0.92, p=0.20). TLR4-dependent TNF-alpha production increased following antibiotic use (1077 vs. 3620pg/mL, p<0.05), whilst TLR2-dependent production was unchanged. CONCLUSIONS: TLR4 expression is decreased in patients with Child-Pugh C cirrhosis, but is restored by antibiotics targeting enteric Gram-negative bacteria. TLR4-dependent cytokine production also increases significantly following antibiotic therapy. This suggests that the high incidence of Gram-negative infection in cirrhotic patients is in part due to down-regulation of the TLR4-dependant immune response and that the efficacy of antibiotic prophylaxis is contributed to by modulation of innate immunity.
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Antibacterianos/farmacologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/imunologia , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Infecções por Bactérias Gram-Negativas/prevenção & controle , Humanos , Imunidade Inata/efeitos dos fármacos , Técnicas In Vitro , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Norfloxacino/farmacologia , Peritonite/prevenção & controle , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
Malnutrition is highly prevalent in liver cirrhosis and its presence carries important prognostic implications. The clinical conditions and pathophysiological mechanisms that cause malnutrition in cirrhosis are multiple and interrelated. Anorexia and liver decompensation symptoms lead to poor dietary intake; metabolic changes characterised by elevated energy expenditure, reduced glycogen storage, an accelerated starvation response and protein catabolism result in muscle and fat wasting; and, malabsorption renders the cirrhotic patient unable to fully absorb or utilise food that has been consumed. Malnutrition is therefore a considerable challenge to manage effectively, particularly as liver disease progresses. A high energy, high protein diet is recognised as standard of care, yet patients struggle to follow this recommendation and there is limited evidence to guide malnutrition interventions in cirrhosis and liver transplantation. In this review, we seek to detail the factors which contribute to poor nutritional status in liver disease, and highlight complexities far greater than "poor appetite" or "reduced oral intake" leading to malnutrition. We also discuss management strategies to optimise nutritional status in this patient group, which target the inter-related mechanisms unique to advanced liver disease. Finally, future research requirements are suggested, to develop effective treatments for one of the most common and debilitating complications afflicting cirrhotic patients.
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Due to advances in modern medicine, liver transplantation has revolutionised the prognosis of many previously incurable liver diseases. This progress has largely been due to advances in immunosuppressant therapy. However, despite the judicious use of immunosuppression, many liver transplant recipients still experience complications such as rejection, which necessitates diagnosis via invasive liver biopsy. There is a clear need for novel, minimally-invasive tests to optimise immunosuppression and improve patient outcomes. An emerging biomarker in this ''precision medicine'' liver transplantation field is that of donor-specific cell free DNA. In this review, we detail the background and methods of detecting this biomarker, examine its utility in liver transplantation and discuss future research directions that may be most impactful.
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The innate immune response to invading pathogens is centred upon a family of non-clonal, germline-encoded pattern recognition receptors (PRRs), the Toll-like receptors (TLRs). These provide specificity for a vast range of microbial pathogens, and offer an immediate anti-microbial response system. Thirteen mammalian TLRs have been described; 10 are expressed in humans, each responsible for the recognition of distinct, invariant microbial structures originating from bacteria, viruses, fungi and protozoa. The two most thoroughly studied are TLR4 and TLR2, the PRRs for Gram-negative and Gram-positive bacterial products, respectively. TLR4 is also the major receptor recognising endogenous ligands released from damaged or dying cells. Activation of a TLR by its relevant ligand rapidly ignites a complex intracellular signaling cascade that ultimately results in upregulation of inflammatory genes and production of proinflammatory cytokines, interferons and recruitment of myeloid cells. It also stimulates expression, upon antigen presenting cells, of co-stimulatory molecules required to induce an adaptive immune response. Whilst a robust TLR response is critical for survival and defence against invading pathogens, inappropriate signaling in response to alterations in the local microflora environment can be detrimental. Such 'unhelpful TLR responses' could form the basis for a large number of gastrointestinal and liver disorders, including inflammatory bowel disease, viral hepatitis, autoimmune liver diseases and hepatic fibrosis. As our understanding of TLRs expands, the pathogenesis of a number of gastrointestinal disorders will be further elucidated, and this offers potential for specific therapies aimed directly at TLR signaling.
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Gastroenteropatias/imunologia , Imunidade Inata/fisiologia , Receptores Toll-Like/imunologia , Animais , Gastroenteropatias/metabolismo , Gastroenteropatias/fisiopatologia , Humanos , Transdução de Sinais/imunologia , Receptores Toll-Like/metabolismo , Receptores Toll-Like/fisiologiaRESUMO
BACKGROUND: Acute liver failure (ALF) is a life-threatening syndrome with varying aetiologies requiring complex care and multidisciplinary management. Its changing incidence, aetiology and outcomes over the last 16 years in the Australian context remain uncertain. AIM: To describe the changing incidence, aetiology and outcomes of ALF in South Eastern Australia. METHODS: The database of the Victorian Liver Transplant Unit was interrogated to identify all cases of ALF in adults (> 16 years) in adults hospitalised between January 2002 and December 2017. Overall, 169 patients meeting criteria for ALF were identified. Demographics, aetiology of ALF, rates of transplantation and outcomes were collected for all patients. Transplant free survival and overall survival (OS) were assessed based on survival to discharge from hospital. Results were compared to data from a historical cohort from the same unit from 1988-2001. RESULTS: Paracetamol was the most common aetiology of acute liver failure, accounting for 50% of cases, with an increased incidence compared with the historical cohort (P = 0.046). Viral hepatitis and non-paracetamol drug or toxin induced liver injury accounted for 15% and 10% of cases respectively. Transplant free survival (TFS) improved significantly compared to the historical cohort (52% vs 38%, P = 0.032). TFS was highest in paracetamol toxicity with spontaneous recovery in 72% of cases compared to 31% of non-paracetamol ALF (P < 0.001). Fifty-nine patients were waitlisted for emergency liver transplantation. Nine of these died while waiting for an organ to become available. Forty-two patients (25%) underwent emergency liver transplantation with a 1, 3 and 5 year survival of 81%, 78% and 72% respectively. CONCLUSION: Paracetamol toxicity is the most common aetiology of ALF in South-Eastern Australia with a rising incidence over 30 years. TFS has improved, however it remains low in non-paracetamol ALF.