Site-specific risk factors for portal vein thrombosis and evaluation of anticoagulation efficacy in patients with cirrhosis

Advanced liver disease is characterized by profound hemostatic alterations that can lead both to bleeding or to thrombotic complications. While pro-hemorrhagic alterations are present including thrombocytopenia and reduced plasmatic levels of coagulation factors, pro-thrombotic abnormalities such as decrease in anti-coagulant proteins antithrombin, Proteins C and S, increase in prothrombotic Factor VIII, and von Willebrand factor are also present. The most frequent site of thrombosis in cirrhotic patients is the portal vein, consequence of an interplay of factors including altered hemostasis and venous stasis. The endothelium, the third component of the thrombosis triad, however, probably plays an important role in the genesis of in situ thrombosis within the portal vein. In the present study, endothelium form portal and cava veins were analyzed in cirrhotic patients, and compared to that of non-cirrhotic subjects, in order to determine the possible role of local alterations in the development of thrombosis. The immunofluorescence study of the main endothelial anticoagulant protein, thrombomodulin, revealed decreased presence of this component in the endothelium of the portal vein with respect to the vena cava in cirrhosis patients. On the other hand, the immunohistochemical analysis of pro-coagulant Factor VIII revealed that this endothelial protein is present uninterruptedly lining the lumen of portal vein and vena cava of both cirrhosis patients and non-cirrhotic subjects, without showing any differences between them. Diminished thrombomodulin may hamper the endothelium’s anticoagulant properties, which, in the presence of conserved Factor VIII, may lead to the development of thrombosis. The thrombosis of the portal vein represents an important milestone in the natural history of patients with cirrhosis, often increasing morbidity before and mortality after liver transplantation. Obtainment of recanalization through anticoagulation is therefore paramount, and in the present study, an analysis was performed regarding factors that may have an impact on efficacy of anticoagulation with low molecular weight heparin in cirrhotic patients with this complication. Anticoagulation with low molecular weight heparin was demonstrated to be a valid strategy for achieving portal vein recanalization, with a response rate of 65.2%, including complete recanalization in 24 of the 46 treated patients, after a mean of 4.5 months (±3.1 months) of anticoagulation. Whereas the hemostatic status of patients did not correlate with the response to anticoagulation, the interval between thrombus onset and start of therapy was the only predictive factor of therapeutic efficacy. Specifically, thrombus age at diagnosis (1.9 ± 1.2 months vs 6.3 ± 4.5 months in the recanalization group and in the non-recanalization group, respectively, p<.001), and the interval between thrombus onset and start of anticoagulation (3.2 ± 1.7 months vs 7.78 ± 4.5 months in the recanalization group and in the non-recanalization group, respectively, p<.002) were the principal determinants of therapeutic efficacy. This underlines the importance of prompt diagnosis and start of therapy to increase the probability of successful anticoagulant therapy. Although in cirrhosis the low levels of antithrombin, which is necessary for the action of heparins, could theoretically hamper the anticoagulant effect, the clinical efficacy of anticoagulant therapy with low molecular weight heparin has been herein demonstrated. The anticoagulant effect of low molecular weight heparin was then tested in vitro using the thrombin generation assay, and concentrations within the therapeutic range achieved reduction of endogenous thrombin potential notwithstanding the marked reduction in antithrombin levels that were present in plasma from cirrhotic patients and the low plasma anti-Xa activity determined in vitro. In particular, patients with Child Pugh C cirrhosis were characterized by antithrombin levels which were as low as those of subjects with the prothrombotic condition of genetic antithrombin deficit (42±14% versus 52±4%, respectively, p=.06). At low molecular weight heparin 0.35 UI/mL concentration in vitro, anti-Xa activity was significantly lower in Child Pugh B and Child Pugh C patients as compared to controls (p<0.001), as well as in patients with congenital AT defect as compared to controls (p<0.001). Despite low levels of antithrombin and anti-Xa activity, patients with cirrhosis showed a greater anticoagulant effect of low molecular weight heparin, with a mean endogenous thrombin potential reduction of 72.6±11% (p=0.02 versus controls). This increased susceptibility of cirrhosis patients with advanced stages of the disease may therefore actually warrant dose reduction of anticoagulation

Site-specific risk factors for portal vein thrombosis and evaluation of anticoagulation efficacy in patients with cirrhosis

Advanced liver disease is characterized by profound hemostatic alterations that can lead both to bleeding or to thrombotic complications. While pro-hemorrhagic alterations are present including thrombocytopenia and reduced plasmatic levels of coagulation factors, pro-thrombotic abnormalities such as decrease in anti-coagulant proteins antithrombin, Proteins C and S, increase in prothrombotic Factor VIII, and von Willebrand factor are also present. The most frequent site of thrombosis in cirrhotic patients is the portal vein, consequence of an interplay of factors including altered hemostasis and venous stasis. The endothelium, the third component of the thrombosis triad, however, probably plays an important role in the genesis of in situ thrombosis within the portal vein. In the present study, endothelium form portal and cava veins were analyzed in cirrhotic patients, and compared to that of non-cirrhotic subjects, in order to determine the possible role of local alterations in the development of thrombosis. The immunofluorescence study of the main endothelial anticoagulant protein, thrombomodulin, revealed decreased presence of this component in the endothelium of the portal vein with respect to the vena cava in cirrhosis patients. On the other hand, the immunohistochemical analysis of pro-coagulant Factor VIII revealed that this endothelial protein is present uninterruptedly lining the lumen of portal vein and vena cava of both cirrhosis patients and non-cirrhotic subjects, without showing any differences between them. Diminished thrombomodulin may hamper the endothelium’s anticoagulant properties, which, in the presence of conserved Factor VIII, may lead to the development of thrombosis. The thrombosis of the portal vein represents an important milestone in the natural history of patients with cirrhosis, often increasing morbidity before and mortality after liver transplantation. Obtainment of recanalization through anticoagulation is therefore paramount, and in the present study, an analysis was performed regarding factors that may have an impact on efficacy of anticoagulation with low molecular weight heparin in cirrhotic patients with this complication. Anticoagulation with low molecular weight heparin was demonstrated to be a valid strategy for achieving portal vein recanalization, with a response rate of 65.2%, including complete recanalization in 24 of the 46 treated patients, after a mean of 4.5 months (±3.1 months) of anticoagulation. Whereas the hemostatic status of patients did not correlate with the response to anticoagulation, the interval between thrombus onset and start of therapy was the only predictive factor of therapeutic efficacy. Specifically, thrombus age at diagnosis (1.9 ± 1.2 months vs 6.3 ± 4.5 months in the recanalization group and in the non-recanalization group, respectively, p<.001), and the interval between thrombus onset and start of anticoagulation (3.2 ± 1.7 months vs 7.78 ± 4.5 months in the recanalization group and in the non-recanalization group, respectively, p<.002) were the principal determinants of therapeutic efficacy. This underlines the importance of prompt diagnosis and start of therapy to increase the probability of successful anticoagulant therapy. Although in cirrhosis the low levels of antithrombin, which is necessary for the action of heparins, could theoretically hamper the anticoagulant effect, the clinical efficacy of anticoagulant therapy with low molecular weight heparin has been herein demonstrated. The anticoagulant effect of low molecular weight heparin was then tested in vitro using the thrombin generation assay, and concentrations within the therapeutic range achieved reduction of endogenous thrombin potential notwithstanding the marked reduction in antithrombin levels that were present in plasma from cirrhotic patients and the low plasma anti-Xa activity determined in vitro. In particular, patients with Child Pugh C cirrhosis were characterized by antithrombin levels which were as low as those of subjects with the prothrombotic condition of genetic antithrombin deficit (42±14% versus 52±4%, respectively, p=.06). At low molecular weight heparin 0.35 UI/mL concentration in vitro, anti-Xa activity was significantly lower in Child Pugh B and Child Pugh C patients as compared to controls (p<0.001), as well as in patients with congenital AT defect as compared to controls (p<0.001). Despite low levels of antithrombin and anti-Xa activity, patients with cirrhosis showed a greater anticoagulant effect of low molecular weight heparin, with a mean endogenous thrombin potential reduction of 72.6±11% (p=0.02 versus controls). This increased susceptibility of cirrhosis patients with advanced stages of the disease may therefore actually warrant dose reduction of anticoagulation.La cirrosi epatica avanzata è caratterizzata da alterazioni emostatiche importanti che possono portare a complicanze emorragiche o trombotiche. Nonostante siano presenti alterazioni pro-emorragiche come trombocitopenia e ridotti livelli dei fattori della coagulazione, sono presenti anche anormalità pro-trombotiche come la diminuzione di proteine anti-coagulanti, quali antitrombina, Proteina C ed S, ed incremento del Fattore VIII e Fattore von Willebrand . Il sito più frequente di trombosi in pazienti cirrotici è la vena porta, risultato di vari fattori quali le alterazioni emostatiche sistemiche così come la stasi venosa locale. Tuttavia, l’endotelio, il terzo componente del triade trombotica, probabilmente gioca un ruolo importante nella genesi della trombosi in situ della vena porta. Nel presente studio, è stato analizzato l’endotelio della vena porta e comparato a quello della vena cava in pazienti cirrotici e non, per determinare il possibile ruolo delle alterazioni locali nello sviluppo della trombosi. Come principale proteina endoteliale anticoagulante, è stata studiata la trombomodulina tramite immunofluorescenza, rivelandone una ridotta presenza nell’endotelio della vena porta rispetto a quello della vena cava nei pazienti cirrotici. D’altro canto, l’analisi immunoistochimica del Fattore VIII, con proprietà pro-coagulanti, ha rivelato che questa proteina endoteliale è presente in maniera continua e costante lungo il lumen della vena porta e della vena cava sia nei pazienti cirrotici che non. La diminuzione della trombomodulina può dannegiare le proprietà anticoagulanti dell’endotelio che, in presenza del Fattore VIII preservato, può portare allo sviluppo della trombosi. La trombosi della vena porta rappresenta una complicanza rilevante nella storia naturale dei pazienti cirrotici, causando frequentemente un aumento della morbilità prima e della mortalità dopo il trapianto epatico. L’ottenimento della ricanalizzazione tramite terapia anticoagulante è perciò importante, e nel presente studio è stata fatta un’analisi dei fattori che possono avere un impatto sull’efficacia della terapia con eparina a basso peso molecolare in pazienti cirrotici con questa complicanza. Si è dimostrato che l’anticoagulazione con eparina a basso peso molecolare è una strategia valida per la ricanalizzazione della vena porta, con un tasso di risposta del 65.2%, includendo ripermeazione completa in 24 dei 46 pazienti trattati, dopo una media di 4.5 mesi (±3.1 mesi) di anticoagulazione. Nonostante lo status emostatico dei pazienti non correlava con la risposta all’anticoagulazione, l’intervallo tra lo sviluppo del trombo e l’inizio della terapia è stato l’unico fattore predittivo dell’efficacia terapeutica. Specificamente, l’età del trombo alla diagnosi (1.9 ± 1.2 mesi vs 6.3 ± 4.5 mesi, rispettivamente, p<.001) e l’intervallo tra lo sviluppo del trombo e l’inizio della terapia anticoagulante (3.2 ± 1.7 mesi vs 7.78 ± 4.5 mesi nel gruppo che ha ottenuto ricanalizzazione e nel gruppo che non ha ottenuto ricanalizzazione, rispettivamente, p<.002) sono stati i principali determinanti dell’efficacia terapeutica. Questo sottolinea l’importanza di una diagnosi precoce e di un opportuno inizio della terapia, per incrementare la probabilità di successo del trattamento anticoagulante. Benché i livelli bassi di antitrombina, necessaria per l’azione dell’eparina, verificatesi in cirrosi possano teoricamente diminuire l’effetto anticoagulante, in questo studio si è dimostrata l’efficacia clinica dell’anticoagulazione con eparina a basso peso molecolare. L’effetto anticoagulante dell’eparina a basso peso molecolare è stato esplorato in vitro utilizzando il test della trombino generazione, e concentrazioni di eparina dentro il range terapeutico sono state in grado di ridurre la generazione della trombina, nonostante la spiccata riduzione nei livelli plasmatici di antitrombina e i bassi livelli di anti-Xa determinati in vitro. In particolare, i pazienti in classe C di Child Pugh si sono caratterizzati da livelli di antitrombina bassi quanto quelli presenti in pazienti con la condizione protrombotica di deficit genetico di questa proteina (42±14% vs 52±4%, rispettivamente, p=.06). Alla concentrazione in vitro di 0.35 UI/mL di eparina a basso peso molecolare, l’attività anti-Xa è stata significativamente più bassa in pazienti in classi di Child Pugh B e C rispetto ai controlli (p<.001), così come in pazienti con difetto genetico dell’antitrombina rispetto ai controlli (p<.001). Nonostante i ridotti livelli di attività anti-Xa, i pazienti cirrotici hanno dimostrato un maggiore effetto anticoagulante dell’eparina a basso peso molecolare, con una riduzione del potenziale endogeno di trombina di 72.6±11% (p=0.02 vs i controlli). Data l’incrementata suscettibilità dei pazienti cirrotici in stadi avanzati della malattia epatica, potrebbe essere necessaria la riduzione della dose di anticoagulazione

HCC criteria for liver transplantation: Controversies

Key Points: 1 Liver transplantation (LT) is considered to be the first-line treatment option for patients with hepatocellular carcinoma (HCC) within Milan criteria not suitable for resection. 2 Extension of tumor limit criteria has not been well established. Modest expansion of Milan criteria applying the “up-to-7” in patients without macrovascular invasion achieves competitive outcomes. 3 Neoadjuvant treatment can be considered before LT (downstaging). 4 After LT, an immunosuppressive regimen containing calcineurin inhibitors has been associated in a dose-dependent fashion with an increased risk of posttransplant HCC recurrence, whereas promising results come from the use of mammalian target of rapamycin inhibitor. 5 Further studies are needed to guarantee allocation equity between patients with and patients without HCC who are waiting for LT

Wilson's disease: A review of what we have learned

Abstract Wilson's disease (WD), which results from the defective ATP7B protein product, is characterized by impaired copper metabolism and its clinical consequences vary from an asymptomatic state to fulminant hepatic failure, chronic liver disease with or without cirrhosis, neurological, and psychiatric manifestations. A high grade of suspicion is warranted to not miss cases of WD, especially less florid cases with only mild elevation of transaminases, or isolated neuropsychiatric involvement. Screening in first and second relatives of index cases is mandatory, and treatment must commence upon establishment of diagnosis. Treatment strategies include chelators such as D-penicillamine and trientine, while zinc salts act as inductors of methallothioneins, which favor a negative copper balance and a reduction of free plasmatic copper. As an orphan disease, research is lacking in this field, especially regarding therapeutic strategies which are associated with better patient compliance and which could eventually also reverse established injury

Anticoagulation for the treatment of thrombotic complications in patients with cirrhosis.

Cirrhotic patients can develop thrombotic complications, which in this group of patients occur with a greater frequency than in the general population. Portal vein thrombosis (PVT) is the most common thrombotic phenomenon, although deep venous thrombosis and pulmonary embolism can also occur. Risk factors for thrombosis include inherited and acquired deficiency of factors involved in anticoagulation mechanisms, venous stasis of the portal vein owing to architectural derangement of the liver and possibly local factors related to the endothelium. Clinical manifestations of PVT range from asymptomatic disease to a life-threatening complication, and although it is no longer considered an absolute contraindication for liver transplant, its presence may require challenging surgical techniques, which entail greater morbidity. Anticoagulation therapy is henceforth an important strategy to treat cirrhotic patients with PVT, although experience in this group of patients is limited. Vitamin K antagonists and low-molecular-weight heparin have been used successfully, achieving recanalization of the thrombosed vessel in patients with cirrhosis; however, the precise drug regimen management and monitoring has not be fully explored in this group of patients

Female gender in the setting of liver transplantation.

The evolution of liver diseases to end-stage liver disease or to acute hepatic failure, the evaluation process for liver transplantation, the organ allocation decision-making, as well as the post-transplant outcomes are different between female and male genders. Women's access to liver transplantation is hampered by the use of model for end-stage liver disease (MELD) score, in which creatinine values exert a systematic bias against women due to their lower values even in the presence of variable degrees of renal dysfunction. Furthermore, even when correcting MELD score for gender-appropriate creatinine determination, a quantifiable uneven access to transplant prevails, demonstrating that other factors are also involved. While some of the differences can be explained from the epidemiological point of view, hormonal status plays an important role. Moreover, the pre-menopausal and post-menopausal stages imply profound differences in a woman's physiology, including not only the passage from the fertile age to the non-fertile stage, but also the loss of estrogens and their potentially protective role in delaying liver fibrosis progression, amongst others. With menopause, the tendency to gain weight may contribute to the development of or worsening of pre-existing metabolic syndrome. As an increasing number of patients are transplanted for non-alcoholic steatohepatitis, and as the average age at transplant increases, clinicians must be prepared for the management of this particular condition, especially in post-menopausal women, who are at particular risk of developing metabolic complications after menopause