Controlled attenuation parameter reflects steatosis in compensated advanced chronic liver disease.

BACKGROUND & AIMS: Controlled attenuation parameter (CAP) for steatosis assessment has not been validated in compensated advanced chronic liver disease compensated advanced chronic liver disease (cACLD). We primarily aimed at assessing the accuracy of CAP for the diagnosis and quantification of steatosis in cACLD. Secondary aim: to assess the validity of non-invasive criteria for cACLD according to liver stiffness measurement (LSM). METHODS: This is a single-centre retrospective study including patients with cACLD defined as LSM ≥10 kPa, CAP measurement and liver biopsy (reference standard for steatosis and fibrosis) observed in 06/2015-06/2017. Steatosis was graded as S0 (<5%), S1 (5%-32%), S2 (33%-66%) and S3 (>66%). The diagnostic performance of CAP for any grade of steatosis and for high-grade steatosis (≥S2) was studied. RESULTS: Among 461 consecutive patients, 111 with LSM-based diagnosis of cACLD were included (63% male, median age 55 years, median body mass index 28.1 Kg/m2 , aetiology: 32% non-alcoholic fatty liver disease/non-alcoholic steatohepatitis, 32% alcohol or viral + metabolic syndrome, 15% viral, 6% autoimmune, 4% alcohol, 11% others). Median LSM and CAP were 16.1 kPa and 277 dB/m respectively. On liver biopsy, steatosis was found in 88/111 patients (79%); 44 patients (43 with metabolic syndrome) had high-grade steatosis. CAP was accurate in identifying any grade of steatosis (area under the receiving operating characteristic curves 0.847; 95% CI 0.767-0.926, P < .0001), and ≥S2 steatosis (0.860; 95% CI 0.788-0.932, P < .0001). CAP performed similarly in patients with CAP- interquartile range (IQR) ≥ or <40 dB/m. CONCLUSIONS: Steatosis is frequent in patients with cACLD and metabolic syndrome. CAP diagnostic accuracy for any steatosis and high-grade steatosis is good in this population. A CAP-IQR ≥40 dB/m does not impair CAP diagnostic accuracy in cACLD.

Non-Invasive Prediction of High-Risk Varices in Patients with Primary Biliary Cholangitis and Primary Sclerosing Cholangitis.

BACKGROUND: Baveno-VI guidelines recommend that patients with compensated cirrhosis with liver stiffness by transient elastography (LSM-TE) <20 kPa and platelets >150,000/mm(3) do not need an esophagogastroduodenoscopy (EGD) to screen for varices, since the risk of having varices needing treatment (VNT) is <5%. It remains uncertain if this tool can be used in patients with cholestatic liver diseases (ChLDs): primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). These patients may have a pre-sinusoidal component of portal hypertension that could affect the performance of this rule. In this study we evaluated the performance of Baveno-VI, expanded Baveno-VI (LSM-TE <25 kPa and platelets >110,000/mm(3)), and other criteria in predicting the absence of VNT. METHODS: This was a multicenter cross-sectional study in four referral hospitals. We retrospectively analyzed data from 227 patients with compensated advanced chronic liver disease (cACLD) due to PBC (n = 147) and PSC (n = 80) that had paired EGD and LSM-TE. We calculated false negative rate (FNR) and number of saved endoscopies for each prediction rule. RESULTS: Prevalence of VNT was 13%. Baveno-VI criteria had a 0% FNR in PBC and PSC, saving 39 and 30% of EGDs, respectively. In PBC the other LSM-TE-based criteria resulted in FNRs >5%. In PSC the expanded Baveno criteria had an adequate performance. In both conditions LSM-TE-independent criteria resulted in an acceptable FNR but saved less EGDs. CONCLUSIONS: Baveno-VI criteria can be applied in patients with cACLD due to ChLDs, which would result in saving 30-40% of EGDs. Expanded criteria in PBC would lead to FNRs >5%.

Prognostic Significance of Controlled Attenuation Parameter in Patients With Compensated Advanced Chronic Liver Disease.

Obesity and steatosis have been associated with liver disease progression in patients with compensated advanced chronic liver disease (cACLD) (liver stiffness measurement [LSM] ≥ 10 kPa). The controlled attenuation parameter (CAP) estimates steatosis during LSM by transient elastography. We aimed to evaluate whether CAP is associated with the development of clinically relevant events in cACLD. Consecutive patients with cACLD and CAP measurements observed between September 2013 and September 2015 were retrospectively studied. Classical decompensation and severe bacterial infections on follow-up were recorded. A predefined CAP cut-off for steatosis was used (220 dB/m; 90% sensitivity). The association among LSM, CAP, and events was assessed by univariate and multivariate Cox regression. Among the 193 patients (viral etiology = 58%; median Child score = 5; LSM = 15.1 kPa; CAP = 255 ± 62 dB/m) who were followed up in median for 18 months, 18 developed clinically relevant events (11 liver decompensation, 7 severe bacterial infections). Patients developing events had higher LSM (median: 30.8 versus 14.3 kPa, P < 0.001) and showed trends for higher CAP (275 ± 46 versus 252 ± 63 dB/m, P = 0.07), lower platelet count (134 ± 74 versus 167 ± 74 G/L, P = 0.07), and worse liver function versus patients remaining compensated. Body mass index was similar in the two groups. All events were more frequent in patients with CAP being greater than or equal to 220 dB/m (12.9% versus 1.6% in CAP < 220; P = 0.013), and 10 of 11 episodes of liver decompensation occurred in patients with CAP being greater than or equal to 220 dB/m. Following multivariate analysis, LSM and CAP greater than or equal to 220 dB/m remained independently associated with clinical events in the whole population and in patients with clinically significant portal hypertension. Conclusion: The CAP being greater than or equal to 220 dB/m is associated with increased risk of clinical decompensation and bacterial infections independent of LSM in patients with cACLD and allows refining the noninvasive risk stratification in this population. (Hepatology Communications 2018; 00:000-000).

Exploring the Role of Killer Cell Immunoglobulin-Like Receptors and Their HLA Class I Ligands in Autoimmune Hepatitis.

BACKGROUND: Natural killer cells are involved in the complex mechanisms underlying autoimmune diseases but few studies have investigated their role in autoimmune hepatitis. Killer immunoglobulin-like receptors are key regulators of natural killer cell-mediated immune responses. METHODS AND FINDINGS: KIR gene frequencies, KIR haplotypes, KIR ligands and combinations of KIRs and their HLA Class I ligands were investigated in 114 patients diagnosed with type 1 autoimmune hepatitis and compared with a group of 221 healthy controls. HLA Class I and Class II antigen frequencies were compared to those of 551 healthy unrelated families representative of the Sardinian population. In our cohort, type 1 autoimmune hepatitis was strongly associated with the HLA-B18, Cw5, DR3 haplotype. The KIR2DS1 activating KIR gene and the high affinity HLA-C2 ligands were significantly higher in patients compared to controls. Patients also had a reduced frequency of HLA-Bw4 ligands for KIR3DL1 and HLA-C1 ligands for KIR2DL3. Age at onset was significantly associated with the KIR2DS1 activating gene but not with HLA-C1 or HLA-C2 ligand groups. CONCLUSIONS: The activating KIR gene KIR2DS1 resulted to have an important predictive potential for early onset of type 1 autoimmune hepatitis. Additionally, the low frequency of the KIR-ligand combinations KIR3DL1/HLA-Bw4 and KIR2DL3/HLA-C1 coupled to the high frequency of the HLA-C2 high affinity ligands for KIR2DS1 could contribute to unwanted NK cell autoreactivity in AIH-1.

Modelling wastewater treatment in a submerged anaerobic membrane bioreactor.

Mathematical modelling has been widely applied to membrane bioreactor (MBRs) processes. However, to date, very few studies have reported on the application of the anaerobic digestion model N.1 (ADM1) to anaerobic membrane processes. The aim of this study was to evaluate the applicability of the ADM1 to a submerged anaerobic MBR (SAMBR) treating simulated industrial wastewater composed of cheese whey and sucrose. This study demonstrated that the biological processes involved in SAMBRs can be modelled by using the ADM1. Moreover, the results showed that very few modifications of the parameters describing the ADM1 were required to reasonably fit the experimental data. In particular, adaptation to the specific conditions of the coefficients describing the wastewater characterisation and the reduction of the hydrolysis rate of particulate carbohydrate (khyd,ch) from 0.25 d(-1) (as suggested by the ADM1 for high-rate mesophilic reactors) to 0.13 d(-1) were required to fit the experimental data.

A prospective observational study on tolerance and satisfaction to hepatic haemodynamic procedures.

BACKGROUND: Understanding patients' attitudes to clinical experiences is essential for developing high-quality patient-centred healthcare, as a better knowledge of patients' tolerance and satisfaction might allow implementing measures that ameliorate comfort, care and use of resources. AIMS: We aimed to describe patients' tolerance and satisfaction to invasive hepatic haemodynamic procedures, and to investigate which factors might influence patients' perspective in this field. METHODS: Visual Analogue Scale (VAS) questionnaires regarding pain and duration (for tolerance), and comfort and general handling (for satisfaction) were prospectively administered to all consecutive patients (N = 327) submitted to hepatic haemodynamic procedures (N = 355) in a tertiary care setting during 2011. VAS scores ranged between 0 and 100 mm and items were defined as excellent if <10 mm; good if 10-20 mm and inadequate if >20 mm. Clinical and laboratory data were also collected. RESULTS: Satisfaction was excellent in >95% of cases (mean 2 ± 5 mm, median 0 mm) and average tolerance was good (15 ± 18 mm; median 6 mm). A percentage of 59% of patients had excellent tolerance, 9% good and 32% had inadequate tolerance. Duration and complexity of the procedure and limited operator's experience were associated with inadequate tolerance on univariate analysis; duration of the procedure remained the only independent factor associated with inadequate tolerance on multivariate analysis. Procedures lasting <35 min had a >80% probability of being well tolerated. CONCLUSIONS: Satisfaction and tolerance to hepatic haemodynamic procedures are excellent and good respectively. Tolerance was decreased in long procedures; hence reducing as much as possible the duration of the procedures might further improve tolerance.

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.

Variceal and other portal hypertension related bleeding.

Variceal bleeding is one of the commonest and most severe complications of liver cirrhosis. Even with the current best medical care, mortality from variceal bleeding is still around 20%. When cirrhosis is diagnosed, varices are present in about 30-40% of compensated patients and in 60% of those who present with ascites. Once varices have been diagnosed, the overall incidence of variceal bleeding is in the order of 25% at two years. Variceal size is the most useful predictor for variceal bleeding, other predictors are severity of liver dysfunction (Child-Pugh classification) and the presence of red wale marks on the variceal wall. The current consensus is that every cirrhotic patient should be endoscopically screened for varices at the time of diagnosis to detect those requiring prophylactic treatment. Non-selective beta-adrenergic blockers (NSBB) and endoscopic band ligation (EBL) have been shown effective in the prevention of first variceal bleeding. The current recommendation for treating acute variceal bleeding is to start vasoactive drug therapy early (ideally during the transferral or to arrival to hospital, even if active bleeding is only suspected) and performing EBL. Once bleeding is controlled, combination therapy with NSBB + EBL should be used to prevent rebleeding. In patients at high risk of treatment failure despite of using this approach, an early covered-TIPS within 72 h (ideally 24 h) should be considered. Data on management of gastric variceal bleeding is limited. No clear recommendation for primary prophylaxis can be done. In acute cardiofundal variceal bleeding, vasoactive agents together with cyanoacrylate (CA) injection seem to be the treatment of choice. Further CA injections and/or NSBB may be used to prevent rebleeding. TIPS or Balloon-occluded retrograde transvenous obliteration when TIPS is contraindicated may be used as a rescue therapy.

Decolourisation of textile wastewater in a submerged anaerobic membrane bioreactor.

Azo dye decolourisation can be easily achieved by biological reduction under anaerobic conditions. The aim of this study was to evaluate the applicability of submerged anaerobic membrane bioreactors (SAMBRs) for the decolourisation of dyeing wastewater containing azo dyes. The reactive orange 16 was used as model of an azo dye. The results demonstrated that very high decolourisation (higher than 99%) can be achieved by SAMBRs. Although decolourisation was not significantly influenced by the azo dye concentrations up to 3.2 g L(-1), methane production was greatly inhibited (up to 80-85%). Since volatile fatty acids accumulated in the treatment system with the azo dye concentration increase, methanogenes seem to be the most sensitive microbial populations of the anaerobic ecological community. The results demonstrated that anaerobic process combined with membrane filtration can deal with highly concentrated wastewaters that result from stream separation of industrial discharges.

Wastewater treatment in a submerged anaerobic membrane bioreactor.

Although most membrane bioreactors are used under aerobic conditions, over the last few years there has been increased interest in their application for anaerobic processes. This paper presents the results obtained when a bench-scale submerged anaerobic membrane bioreactor was used for the treatment of wastewaters generated in the agro-food industry. The reactor was fed with synthetic wastewater consisting of cheese whey and sucrose, and volumetric organic loading rates (OLRs) ranging from 1.5 to 13 kgCOD/(m(3)*d) were applied. Under the operating conditions studied, the maximum applicable OLR was between 6 and 10 gCOD/(g*L), which fell within the ranges of the high-rate anaerobic wastewater treatment systems, while high concentrations of volatile fatty acids were produced at higher OLR rates. With an OLR of 1.5-10 gCOD/(g*L), the reactor showed 94% COD removal, whereas this value dropped to 33% with the highest applied OLR of 13 gCOD/(g*L). The study therefore confirms that membrane bioreactors can be used for anaerobic wastewater treatment.

Textile wastewater treatment in a bench-scale anaerobic-biofilm anoxic-aerobic membrane bioreactor combined with nanofiltration.

This study evaluated the treatability of textile wastewaters in a bench-scale experimental system, comprising an anaerobic biofilter, an anoxic reactor and an aerobic membrane bioreactor (MBR). The MBR effluent was thereafter treated by a nanofiltration (NF) membrane. The proposed system was demonstrated to be effective in the treatment of the textile wastewater under the operating conditions applied in the study. The MBR system achieved a good COD (90-95%) removal; due to the presence of the anaerobic biofilter, also effective color removal was obtained (70%). The addition of the NF membrane allowed the further improvement in COD (50-80%), color (70-90%) and salt removal (60-70% as conductivity). In particular the NF treatment allowed the almost complete removal of the residual color and a reduction of the conductivity such as to achieve water quality suitable for reuse.

Effect of the organic loading rate on biogas composition in continuous fermentative hydrogen production.

Some systems did not select for hydrogen-producing microorganisms and an unexpected growth of hydrogenotrophic methanogens was observed, although the reactors were operated under well-defined operating conditions that could result in biohydrogen production. The aim of this study was to evaluate the effect of the organic loading rate (OLR) on the hydrogen and methane composition of the biogas produced in dark fermentative processes. The study was carried out using an upflow anaerobic sludge blanket (UASB) reactor in order to evaluate the OLR effect in systems with sludge retention. During continuous operation, the UASB reactor showed the slow development of methanogenic activity, related to the applied OLR. The results demonstrate that operating an UASB reactor at pH 5.5 is not enough to prevent the acclimation of methanogens to the acidic pH and therefore long-term biohydrogen production cannot be achieved. Moreover, this study demonstrates that OLR also has an effect on the biogas composition, where the higher the OLR the greater the biogas H2 content.