Predicting portal thrombosis in cirrhosis: A prospective study of clinical, ultrasonographic and hemostatic factors.

BACKGROUND & AIMS: Portal vein thrombosis (PVT) is a relatively frequent event in patients with cirrhosis. While different risk factors for PVT have been reported, such as decreased portal blood flow velocity (PBFV) and parameters related with severity of portal hypertension, these are based on retrospective studies assessing only a discrete number of parameters. The aim of the current study was to evaluate the incidence and risks factors for non-tumoral PVT development in a large prospective cohort of patients with cirrhosis. METHODS: We performed an exhaustive evaluation of clinical, biochemical, inflammatory and acquired/hereditary hemostatic profiles in 369 patients with cirrhosis without PVT who were prospectively followed-up. Doppler ultrasound was performed at baseline and every 6 months or whenever clinically indicated. PVT development was always confirmed by computed tomography. RESULTS: Twenty-nine patients developed non-tumoral PVT, with an incidence of 1.6%, 6% and 8.4% at 1, 3 and 5 years, respectively. Low platelet count, PBFV <15 cm/sec and history of variceal bleeding were factors independently associated with a high PVT risk. No relationship between PVT development and any other clinical biochemical, inflammatory and acquired or hereditary hemostatic parameter was found. CONCLUSIONS: In patients with cirrhosis, the factors predictive of PVT development were mainly those related to the severity of portal hypertension. Our results do not support the role of hemostatic alterations (inherited or acquired) and inflammatory markers in the prediction of PVT in patients with cirrhosis. LAY SUMMARY: Patients with cirrhosis and more severe portal hypertension are at higher risk of non-tumoral portal vein thrombosis development. Acquired or inherited hemostatic disorders, as well as inflammatory status, do not seem to predict the development of portal vein thrombosis in patients with cirrhosis.

Autoimmune biomarkers in porto-sinusoidal vascular disease: Potential role in its diagnosis and pathophysiology.

BACKGROUND AND AIMS: Porto-sinusoidal vascular disease (PSVD) is a rare disease that requires excluding cirrhosis and other causes of portal hypertension for its diagnosis because it lacks a specific diagnostical test. Although it has been occasionally associated with autoimmune diseases, the pathophysiology of PSVD remains unknown. The aim of this study was to evaluate the potential role of autoimmunity in the pathophysiology and diagnosis of PSVD. METHODS: Thirty-seven consecutive patients with PSVD and 39 with cirrhosis matched by gender, signs of portal hypertension and liver function were included (training set). By using Indirect Immunofluorescence, ELISA and slot-blot methods data 22 autoantibodies were identified in patients with PSVD and cirrhosis. Presence of anti-endothelial cells antibodies (AECA) was assayed by a cell-based ELISA. Thirty-one PSVD, 40 cirrhosis patients, 15 patients with splenomegaly associated with haematological disease and 14 healthy donors were included in a validation set. FINDINGS: The proportion of patients with at least one positive antibody was statistically significantly higher in patients with PSVD compared with cirrhosis (92% vs 56%; P < .01). Specifically, AECA were significantly more frequent in PSVD than in cirrhosis (38% vs 15%; P = .013). Results were confirmed in the validation set. In the overall population, presence of AECA had a 63% positive predictive value for diagnosing PSVD and a 71% negative predictive value, with a specificity of 94% when the 1/16 level is used as cut-off. AECA positive serum samples react with a 68-72 kDa protein of human liver endothelial sinusoidal cells.

Co-expression gene network analysis reveals novel regulatory pathways involved in porto-sinusoidal vascular disease.

BACKGROUND & AIMS: Porto-sinusoidal vascular disease (PSVD) is a rare vascular liver disease of unknown etiology that causes portal hypertension. It usually affects young individuals and shortens live expectancy. The deregulated pathways involved in PSVD development are unknown and therefore we lack curative treatments. The purpose of this study was to integrate transcriptomic and clinical data by comprehensive network-based modeling in order to uncover altered biological processes in patients with PSVD. METHODS: We obtained liver tissue samples from 20 consecutive patients with PSVD and 21 sex- and age-matched patients with cirrhosis and 13 histologically normal livers (HNL) (initial cohort) and performed transcriptomic analysis. Microarray data were analyzed using weighted gene correlation network analysis to identify clusters of highly correlated genes differently expressed in patients with PSVD. We next evaluated the molecular pathways enriched in patients with PSVD and the core-related genes from the most significantly enriched pathways in patients with PSVD. Our main findings were validated using RNA sequencing in a different cohort of PSVD, cirrhosis and HNL (n = 8 for each group). RESULTS: Patients with PSVD have a distinctive genetic profile enriched mainly in canonical pathways involving hemostasis and coagulation but also lipid metabolism and oxidative phosphorylation. Serpin family (SERPINC1), the apolipoproteins (APOA, APOB, APOC), ATP synthases (ATP5G1, ATP5B), fibrinogen genes (FGB, FGA) and alpha-2-macroglobulin were identified as highly connective genes that may have an important role in PSVD pathogenesis. CONCLUSION: PSVD has a unique transcriptomic profile and we have identified deregulation of pathways involved in vascular homeostasis as the main pathogenic event of disease development. LAY SUMMARY: Porto-sinusoidal vascular disease is a rare but life-shortening disease that affects mainly young people. Knowledge of the disrupted pathways involved in its development will help to identify novel therapeutic targets and new treatments. Using a systems biology approach, we identify that pathways regulating endothelial function and tone may act as drivers of porto-sinusoidal vascular disease.

Development of a hyperimmune equine serum therapy for COVID-19 in Argentina.

The disease named COVID-19, caused by the SARS-CoV-2 coronavirus, is currently generating a global pandemic. Vaccine development is no doubt the best long-term immunological approach, but in the current epidemiologic and health emergency there is a need for rapid and effective solutions. Convalescent plasma is the only antibody-based therapy available for COVID-19 patients to date. Equine polyclonal antibodies (EpAbs) put forward a sound alternative. The new generation of processed and purified EpAbs containing highly purified F(ab')2 fragments demonstrated to be safe and well tolerated. EpAbs are easy to manufacture allowing a fast development and scaling up for a treatment. Based on these ideas, we present a new therapeutic product obtained after immunization of horses with the receptor-binding domain of the viral Spike glycoprotein. Our product shows around 50 times more potency in in vitro seroneutralization assays than the average of convalescent plasma. This result may allow us to test the safety and efficacy of this product in a phase 2/3 clinical trial to be conducted in July 2020 in the metropolitan area of Buenos Aires, Argentina.

La enfermedad denominada COVID-19 es causada por el coronavirus SARS-CoV-2 y es actualmente considerada una pandemia a nivel global. El desarrollo de vacunas es sin duda la mejor estrategia a largo plazo, pero debido a la emergencia sanitaria, existe una necesidad urgente de encontrar soluciones rápidas y efectivas para el tratamiento de la enfermedad. Hasta la fecha, el uso de plasma de convalecientes es la única inmunoterapia disponible para pacientes hospitalizados con COVID-19. El uso de anticuerpos policlonales equinos (EpAbs) es otra alternativa terapéutica interesante. La nueva generación de EpAbs incluyen el procesamiento y purificación de los mismos y la obtención de fragmentos F(ab')2 con alta pureza y un excelente perfil de seguridad en humanos. Los EpAbs son fáciles de producir, lo cual permite el desarrollo rápido y la elaboración a gran escala de un producto terapéutico. En este trabajo mostramos el desarrollo de un suero terapéutico obtenido luego de la inmunización de caballos utilizando el receptor-binding domain de la glicoproteína Spike del virus. Nuestro producto mostró ser alrededor de 50 veces más potente en ensayos de seroneutralización in vitro que el promedio de los plasmas de convalecientes. Estos resultados nos permitirían testear la seguridad y eficacia de nuestro producto en ensayos clínicos de fase 2/3 a realizarse a partir de julio de 2020 en la zona metropolitana de Buenos Aires, Argentina.

Development of a hyperimmune equine serum therapy for COVID-19 in Argentina

The disease named COVID-19, caused by the SARS-CoV-2 coronavirus, is currently generating a global pandemic. Vaccine development is no doubt the best long-term immunological approach, but in the current epidemiologic and health emergency there is a need for rapid and effective solutions. Convalescent plasma is the only antibody-based therapy available for COVID-19 patients to date. Equine polyclonal antibodies (EpAbs) put forward a sound alternative. The new generation of processed and purified EpAbs containing highly purified F(ab’)2 fragments demonstrated to be safe and well tolerated. EpAbs are easy to manufacture allowing a fast development and scaling up for a treatment. Based on these ideas, we present a new therapeutic product obtained after immunization of horses with the receptor-binding domain of the viral Spike glycoprotein. Our product shows around 50 times more potency in in vitro seroneutralization assays than the average of convalescent plasma. This result may allow us to test the safety and efficacy of this product in a phase 2/3 clinical trial to be conducted in July 2020 in the metropolitan area of Buenos Aires, Argentina.

La enfermedad denominada COVID-19 es causada por el coronavirus SARS-CoV-2 y es actualmente considerada una pandemia a nivel global. El desarrollo de vacunas es sin duda la mejor estrategia a largo plazo, pero debido a la emergencia sanitaria, existe una necesidad urgente de encontrar soluciones rápidas y efectivas para el tratamiento de la enfermedad. Hasta la fecha, el uso de plasma de convalecientes es la única inmunoterapia disponible para pacientes hospitalizados con COVID-19. El uso de anticuerpos policlonales equinos (EpAbs) es otra alternativa terapéutica interesante. La nueva generación de EpAbs incluyen el procesamiento y purificación de los mismos y la obtención de fragmentos F(ab’)2 con alta pureza y un excelente perfil de seguridad en humanos. Los EpAbs son fáciles de producir, lo cual permite el desarrollo rápido y la elaboración a gran escala de un producto terapéutico. En este trabajo mostramos el desarrollo de un suero terapéutico obtenido luego de la inmunización de caballos utilizando el receptor-binding domain de la glicoproteína Spike del virus. Nuestro producto mostró ser alrededor de 50 veces más potente en ensayos de seroneutralización in vitro que el promedio de los plasmas de convalecientes. Estos resultados nos permitirían testear la seguridad y eficacia de nuestro producto en ensayos clínicos de fase 2/3 a realizarse a partir de julio de 2020 en la zona metropolitana de Buenos Aires, Argentina.

Metabolomics discloses potential biomarkers to predict the acute HVPG response to propranolol in patients with cirrhosis.

BACKGROUND: In cirrhosis, a decrease in hepatic venous pressure gradient (HVPG) > 10% after acute iv propranolol (HVPG response) is associated with a lower risk of decompensation and death. Only a part of patients are HVPG responders and there are no accurate non-invasive markers to identify them. We aimed at discovering metabolomic biomarkers of HVPG responders to propranolol. METHODS: Sixty-six patients with cirrhosis and HVPG ≥ 10 mm Hg in whom the acute HVPG response to propranolol was assessed, were prospectively included. A targeted metabolomic serum analysis using ultrahigh-performance liquid chromatography coupled to mass spectrometry was performed. Different combinations of 2-3 metabolites identifying HVPG responders (HVPG reduction > 10%) were obtained by stepwise logistic regression. The best of these model (AUROC, Akaike criterion) underwent internal cross-validation and cut-offs to classify responders/non-responders was proposed. RESULTS: A total of 41/66 (62%) patients were HVPG responders. Three hundred and eighty-nine metabolites were detected and 177 were finally eligible. Eighteen metabolites were associated to the HVPG response at univariate analysis; at multivariable analysis, a model including a phosphatidylcholine (PC(P-16:0/22:6)) and a free fatty acid (20:2(n-6), eicosadienoic acid) performed well for HVPG response, with an AUROC of 0.801 (0.761 at internal validation). The cut-off 0.629 was the most efficient for overall classification (49/66 patients correctly classified). Two cut-off values allowed identifying responders (0.688, PPV 84%) and non-responders (0.384, NPV 82%) with undetermined values for 17/66 patients. Clinical variables did not add to the model. CONCLUSIONS: The combination of two metabolites helps at identifying HVPG responders to acute propranolol. It could be a useful non-invasive test to classify the HVPG response to propranolol.

Antithrombotic treatment with direct-acting oral anticoagulants in patients with splanchnic vein thrombosis and cirrhosis.

BACKGROUND: Direct-acting oral anticoagulants (DOACs) are used in patients with splanchnic vein thrombosis (SVT) and cirrhosis, but evidence for safety and efficacy in this setting is limited. Our aim was to identify indications and reasons for starting or switching to DOACs and to report adverse effects, complications and short-term outcome. METHODS: Data collection including demographic information, laboratory values, treatment and complications through the Vascular Liver Disease Interest Group Consortium. RESULTS: Forty-five centres (90%) of the consortium completed the initial eCRF. We report here a series of 94 patients from 17 centres. Thirty-six patients (38%) had cirrhosis. Child-Pugh score was 6 (range 5-8), and MELD score 10.2 (range 6-19). Indications for anticoagulation were splanchnic vein thrombosis (75%), deep vein thrombosis (5%), atrial fibrillation (14%) and others (6%). DOACs used were rivaroxaban (83%), dabigatran (11%) and apixaban (6%). Patients were followed up for a median duration of 15 months (cirrhotic) and 26.5 months (non-cirrhotic). Adverse events occurred in 17% of patients and included one case of recurrent portal vein thrombosis and five cases of bleeding. Treatment with DOACs was stopped in three cases. The major reasons for choosing DOACs were no need for monitoring or inadequacy of INR to guide anticoagulation in cirrhotic patients. Renal and liver function did not change during treatment. CONCLUSIONS: A consistent number of patients with SVT and/or cirrhosis are currently treated with DOACs, which seem to be effective and safe. These data provide a basis for performing randomized clinical trials of DOACs vs. low molecular weight heparin or vitamin K antagonists.

A T4SS Effector Targets Host Cell Alpha-Enolase Contributing to Brucella abortus Intracellular Lifestyle.

Brucella abortus, the causative agent of bovine brucellosis, invades and replicates within cells inside a membrane-bound compartment known as the Brucella containing vacuole (BCV). After trafficking along the endocytic and secretory pathways, BCVs mature into endoplasmic reticulum-derived compartments permissive for bacterial replication. Brucella Type IV Secretion System (VirB) is a major virulence factor essential for the biogenesis of the replicative organelle. Upon infection, Brucella uses the VirB system to translocate effector proteins from the BCV into the host cell cytoplasm. Although the functions of many translocated proteins remain unknown, some of them have been demonstrated to modulate host cell signaling pathways to favor intracellular survival and replication. BPE123 (BAB2_0123) is a B. abortus VirB-translocated effector protein recently identified by our group whose function is yet unknown. In an attempt to identify host cell proteins interacting with BPE123, a pull-down assay was performed and human alpha-enolase (ENO-1) was identified by LC/MS-MS as a potential interaction partner of BPE123. These results were confirmed by immunoprecipitation assays. In bone-marrow derived macrophages infected with B. abortus, ENO-1 associates to BCVs in a BPE123-dependent manner, indicating that interaction with translocated BPE123 is also occurring during the intracellular phase of the bacterium. Furthermore, ENO-1 depletion by siRNA impaired B. abortus intracellular replication in HeLa cells, confirming a role for α-enolase during the infection process. Indeed, ENO-1 activity levels were enhanced upon B. abortus infection of THP-1 macrophagic cells, and this activation is highly dependent on BPE123. Taken together, these results suggest that interaction between BPE123 and host cell ENO-1 contributes to the intracellular lifestyle of B. abortus.

Actuación ante la trombosis portal no cirrótica no tumoral / Treatment of non-cirrhotic, non-tumoural portal vein thrombosis

La trombosis del eje esplenoportal (TVP) no asociada a cirrosis hepática o neoplasias es una enfermedad rara con prevalencia que oscila entre el 0,7 y el 3,7 por 100.000 habitantes. Sin embargo, es la segunda causa de hipertensión portal. Hasta el 70% de los pacientes presentan factores protrombóticos como causa subyacente y entre el 10 y el 50%, factores locales. Es frecuente la coexistencia de varias entidades etiológicas. La presentación clínica puede ser aguda o crónica (cavernomatosis portal). La fase aguda se puede manifestar como dolor abdominal, náuseas, vómitos, fiebre, rectorragia, congestión intestinal e isquemia. Es esencial el inicio precoz de la anticoagulación en esta fase para conseguir la recanalización portal y, con ello, mejorar el pronóstico del paciente. En la fase de cavernomatosis portal, los síntomas vienen derivados del síndrome de hipertensión portal. En esta fase el tratamiento va dirigido a tratar o prevenir las complicaciones de la hipertensión portal. La anticoagulación quedará reservada a aquellos pacientes en los que se demuestre un factor trombofílico subyacente

Thrombosis of the splenoportal axis not associated with liver cirrhosis or neoplasms is a rare disease whose prevalence ranges from 0.7 to 3.7 per 100,000 inhabitants. However, this entity is the second most common cause of portal hypertension. Prothrombotic factors are present as an underlying cause in up to 70% of patients and local factors in 10-50%. The coexistence of several etiological factors is frequent. Clinical presentation may be acute or chronic (portal cavernomatosis). The acute phase can present as abdominal pain, nausea, vomiting, fever, rectorrhagia, intestinal congestion, and ischemia. In this phase, early initiation of anticoagulation is essential to achieve portal vein recanalization and thus improve patient prognosis. In the chronic phase, symptoms are due to portal hypertension syndrome. In this phase, the aim of treatment is to treat or prevent the complications of portal hypertension. Anticoagulation is reserved to patients with a proven underlying thrombophilic factor

Natural history and management of esophagogastric varices in chronic noncirrhotic, nontumoral portal vein thrombosis.

UNLABELLED: In patients with chronic noncirrhotic, nontumoral portal vein thrombosis (PVT), the usually recommended strategy for endoscopic screening and management of varices is the same as in cirrhosis. However, the efficacy of this policy in patients with PVT is unknown. We assessed the course of gastroesophageal varices in a large cohort of patients with chronic PVT. Patients prospectively registered in two referral centers for vascular liver disorders were eligible for the study. Endpoints were development and growth of varices and the incidence and outcome of portal hypertension-related bleeding. Included were 178 patients with chronic PVT. Median follow-up was 49 (1-598) months. Variceal bleeding was the initial manifestation in 27 (15%) patients. Initial endoscopy in the remaining 151 patients showed no varices in 52 (34%), small esophageal varices in 28 (19%), large esophageal varices (LEVs) in 60 (40%), and gastric varices without LEVs in 11 (7%). Ascites and splenomegaly were independent predictors for the presence of varices. In patients without varices, the probability of developing them was 2%, 22%, and 22% at 1, 3, and 5 years, respectively. In those with small esophageal varices, growth to LEVs was observed in 13%, 40%, and 54% at 1, 3, and 5 years, respectively. In patients with LEVs on primary prophylaxis, probability of bleeding was 9%, 20%, and 32% at 1, 3, and 5 years, respectively. Nine (5%) patients died after a median 51 (8-280) months, only one due to variceal bleeding. CONCLUSIONS: The course of varices in chronic noncirrhotic, nontumoral PVT appears to be similar to that in cirrhosis; using the same therapeutic approach as for cirrhosis is associated with a low risk of bleeding and death.

Metabolomics as a diagnostic tool for idiopathic non-cirrhotic portal hypertension.

BACKGROUND: Idiopathic non-cirrhotic portal hypertension (INCPH) is a rare life-threatening liver disease that lacks a specific diagnostic test being frequently misdiagnosed as cryptogenic cirrhosis. Preliminary data from our group identified a plasma metabolomic profile able to differentiate INCPH from patients with cirrhosis (CH) and healthy volunteers (HV). However, the untargeted methodology applied was unable to identify all the specific metabolites, hampering the possibility of building-up diagnostic models. This study applies a wide-coverage of previously identified metabolites through a high-throughput metabolomics technology, evaluating if there is a metabolomic profile that allows a non-invasive diagnosis of INCPH. METHODS: We included 34 patients with INCPH, 34 with CH and 34 HV. We performed a targeted metabolomic analysis of serum samples using UPLC-MS. The best combination of a set of specific metabolites was obtained using stepwise logistic regression (LR) and recursive partitioning analysis (RPA). RESULTS: After internal cross-validation, LR analysis identified a subset of 5-metabolites that clearly differentiate INCPH patients from CH and HV (average corrected optimism AUROC = 0.8871 [0.838-0.924]). Using high and low cut-off values the model has an excellent capacity to respectively diagnose or exclude INCPH. The RPA analysis strategy used the 3-metabolites signature differentiating INCPH from CH and the 2-metabolites signature differentiating INCPH from HV. A decision tree applying sequentially these metabolic profiles diagnosed 88% of INCPH patients. CONCLUSIONS: Different metabolomic profiles allow the diagnosis of INCPH with high specificity and sensibility and may represent excellent clinical tools for its diagnosis avoiding multiple and invasive tests.

[Treatment of non-cirrhotic, non-tumoural portal vein thrombosis]. / Actuación ante la trombosis portal no cirrótica no tumoral.

Thrombosis of the splenoportal axis not associated with liver cirrhosis or neoplasms is a rare disease whose prevalence ranges from 0.7 to 3.7 per 100,000 inhabitants. However, this entity is the second most common cause of portal hypertension. Prothrombotic factors are present as an underlying cause in up to 70% of patients and local factors in 10-50%. The coexistence of several etiological factors is frequent. Clinical presentation may be acute or chronic (portal cavernomatosis). The acute phase can present as abdominal pain, nausea, vomiting, fever, rectorrhagia, intestinal congestion, and ischemia. In this phase, early initiation of anticoagulation is essential to achieve portal vein recanalization and thus improve patient prognosis. In the chronic phase, symptoms are due to portal hypertension syndrome. In this phase, the aim of treatment is to treat or prevent the complications of portal hypertension. Anticoagulation is reserved to patients with a proven underlying thrombophilic factor.

Effects of Sapropterin on Portal and Systemic Hemodynamics in Patients With Cirrhosis and Portal Hypertension: A Bicentric Double-Blind Placebo-Controlled Study.

OBJECTIVES: Tetrahydrobiopterin (BH4), a cofactor of nitric oxide synthase, might have a role in the treatment of portal hypertension (PHT) as its administration improves endothelial nitric oxide generation and hepatic endothelial dysfunction, and reduces portal pressure in experimental models of cirrhosis. Sapropterin is an oral synthetic analogue of BH4 recently approved for the treatment of phenylketonuria. This study evaluated the safety and effects of sapropterin on hepatic and systemic hemodynamics in patients with cirrhosis and PHT. METHODS: Forty patients with cirrhosis and PHT (hepatic venous pressure gradient (HVPG) ≥10 mm Hg) were randomly allocated to receive sapropterin (n=19) for 2 weeks (5 mg/kg/day increased to 10 at day 8) or placebo (n=21) in a double-blind multicenter clinical trial. Randomization was stratified according to concomitant treatment with ß-adrenergic blockers. We studied at baseline and post-treatment splanchnic (HVPG and hepatic blood flow (HBF)) and systemic hemodynamics, endothelial dysfunction and oxidative stress markers (von Willebrand factor and malondialdehyde), liver function tests, and safety variables. RESULTS: HVPG was not modified by either sapropterin (16.0±4.4 vs. 15.8±4.7 mm Hg) or placebo (16.0±4.6 vs. 15.5±4.9 mm Hg). HBF, systemic hemodynamics, endothelial dysfunction markers, and liver function tests remained unchanged. Sapropterin was well tolerated (no patient required dose adjustment or withdrawal), and adverse events were mild and similar between groups. CONCLUSIONS: Sapropterin, an oral synthetic analogue of BH4, at the used dose did not reduce portal pressure in patients with cirrhosis. Sapropterin was safe and no serious adverse effects or deleterious systemic hemodynamic effects were observed.

Idiopathic non-cirrhotic portal hypertension: a review.

Idiopathic non-cirrhotic portal hypertension (INCPH) is a rare disease characterized of intrahepatic portal hypertension in the absence of cirrhosis or other causes of liver disease and splanchnic venous thrombosis. The etiology of INCPH can be classified in five categories: 1) immunological disorders (i.e. association with common variable immunodeficiency syndrome, connective tissue diseases, Crohn's disease, etc.), 2) chronic infections, 3) exposure to medications or toxins (e.g. azathioprine, 6- thioguanine, arsenic), 4) genetic predisposition (i.e. familial aggregation and association with Adams-Oliver syndrome and Turner disease) and 5) prothrombotic conditions (e.g. inherited thrombophilias myeloproliferative neoplasm antiphospholipid syndrome). Roughly, INCPH diagnosis is based on clinical criteria and the formal exclusion of any other causes of portal hypertension. A formal diagnosis is based on the following criteria: 1) presence of unequivocal signs of portal hypertension, 2) absence of cirrhosis, advanced fibrosis or other causes of chronic liver diseases, and 3) absence of thrombosis of the hepatic veins or of the portal vein at imaging. Patients with INCPH usually present with signs or symptoms of portal hypertension such as gastro-esophageal varices, variceal bleeding or splenomegaly. Ascites and/or liver failure can occur in the context of precipitating factors. The development of portal vein thrombosis is common. Survival is manly limited by concomitant disorders. Currently, treatment of INCPH relies on the prevention of complications related to portal hypertension, following current guidelines of cirrhotic portal hypertension. No treatment has been studied aimed to modify the natural history of the disease. Anticoagulation therapy can be considered in patients who develop portal vein thrombosis.

Interaction network and localization of Brucella abortus membrane proteins involved in the synthesis, transport, and succinylation of cyclic ß-1,2-glucans.

UNLABELLED: Cyclic ß-1,2-glucans (CßG) are periplasmic homopolysaccharides that play an important role in the virulence and interaction of Brucella with the host. Once synthesized in the cytoplasm by the CßG synthase (Cgs), CßG are transported to the periplasm by the CßG transporter (Cgt) and succinylated by the CßG modifier enzyme (Cgm). Here, we used a bacterial two-hybrid system and coimmunoprecipitation techniques to study the interaction network between these three integral inner membrane proteins. Our results indicate that Cgs, Cgt, and Cgm can form both homotypic and heterotypic interactions. Analyses carried out with Cgs mutants revealed that the N-terminal region of the protein (Cgs region 1 to 418) is required to sustain the interactions with Cgt and Cgm as well as with itself. We demonstrated by single-cell fluorescence analysis that in Brucella, Cgs and Cgt are focally distributed in the membrane, particularly at the cell poles, whereas Cgm is mostly distributed throughout the membrane with a slight accumulation at the poles colocalizing with the other partners. In summary, our results demonstrate that Cgs, Cgt, and Cgm form a membrane-associated biosynthetic complex. We propose that the formation of a membrane complex could serve as a mechanism to ensure the fidelity of CßG biosynthesis by coordinating their synthesis with the transport and modification. IMPORTANCE: In this study, we analyzed the interaction and localization of the proteins involved in the synthesis, transport, and modification of Brucella abortus cyclic ß-1,2-glucans (CßG), which play an important role in the virulence and interaction of Brucella with the host. We demonstrate that these proteins interact, forming a complex located mainly at the cell poles; this is the first experimental evidence of the existence of a multienzymatic complex involved in the metabolism of osmoregulated periplasmic glucans in bacteria and argues for another example of pole differentiation in Brucella. We propose that the formation of this membrane complex could serve as a mechanism to ensure the fidelity of CßG biosynthesis by coordinating synthesis with the transport and modification.

Anticoagulación de la trombosis venosa portal en la cirrosis / Anticoagulation for thrombosis of the portal vein in cirrhosis

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Impact of deep sedation on the accuracy of hepatic and portal venous pressure measurements in patients with cirrhosis.

BACKGROUND & AIMS: Measurement of the hepatic venous pressure gradient (HVPG) offers valuable prognostic information in patients with cirrhosis. In specific circumstances, (children, agitated patients, TIPS placement) deep sedation is required. This study aims to assess the impact of deep sedation on the accuracy of hepatic/portal pressure measurements. METHODS: Forty-four patients were included. Measurements of baseline HVPG (n = 30), HVPG response to i.v. propranolol (n = 11), portal pressure gradient (PPG) after TIPS (n = 27) and of cardio-pulmonary pressures (n = 25) were obtained in awake conditions and under deep sedation with propofol and remifentanil. RESULTS: During deep sedation, a marked oscillation within respiratory cycle was observed in abdominal pressures. End-expiratory sedated HVPG showed a better agreement with awake HVPG (intra-class correlation coefficient - ICC 0.864) than end-inspiratory HVPG (ICC 0.796). However, in almost half of the patients both values differed by more than 10%. Accuracy was not improved by using mean HVPG along the respiratory cycle. Similarly, changes in HVPG caused by propranolol while under sedation had a poor agreement to those obtained in awake conditions. Indeed, about a half of patients were misclassified according to the 10% HVPG reduction target. After TIPS, PPG values obtained under sedation were significantly different to awake PPG, usually underestimating the awake value. The systemic hemodynamic changes induced by sedation were not associated to a greater variability of PPG/HVPG measurements. CONCLUSION: Deep sedation with propofol and remifentanil adds substantial variability and uncertainty to HVPG/PPG measurements. This must be considered when using these values to estimate prognosis, or targeting HVPG/PPG reductions.

A MELD-based model to determine risk of mortality among patients with acute variceal bleeding.

BACKGROUND & AIMS: Patients with cirrhosis with acute variceal bleeding (AVB) have high mortality rates (15%-20%). Previously described models are seldom used to determine prognoses of these patients, partially because they have not been validated externally and because they include subjective variables, such as bleeding during endoscopy and Child-Pugh score, which are evaluated inconsistently. We aimed to improve determination of risk for patients with AVB. METHODS: We analyzed data collected from 178 patients with cirrhosis (Child-Pugh scores of A, B, and C: 15%, 57%, and 28%, respectively) and esophageal AVB who received standard therapy from 2007 through 2010. We tested the performance (discrimination and calibration) of previously described models, including the model for end-stage liver disease (MELD), and developed a new MELD calibration to predict the mortality of patients within 6 weeks of presentation with AVB. MELD-based predictions were validated in cohorts of patients from Canada (n = 240) and Spain (n = 221). RESULTS: Among study subjects, the 6-week mortality rate was 16%. MELD was the best model in terms of discrimination; it was recalibrated to predict the 6-week mortality rate with logistic regression (logit, -5.312 + 0.207 • MELD; bootstrapped R(2), 0.3295). MELD values of 19 or greater predicted 20% or greater mortality, whereas MELD scores less than 11 predicted less than 5% mortality. The model performed well for patients from Canada at all risk levels. In the Spanish validation set, in which all patients were treated with banding ligation, MELD predictions were accurate up to the 20% risk threshold. CONCLUSIONS: We developed a MELD-based model that accurately predicts mortality among patients with AVB, based on objective variables available at admission. This model could be useful to evaluate the efficacy of new therapies and stratify patients in randomized trials.