Non-invasive liver fibrosis tests in non-alcoholic fatty liver disease

In the last two decades, several non-invasive liver fibrosis tests have been introduced in clinical practice and transformed the investigation of patients with non-alcoholic fatty liver disease. In this editorial, we summarize the role of such tests in the management of patients with non-alcoholic fatty liver disease, focusing on their strengths and pitfalls in different clinical settings and scenarios

Ursodeoxycholic acid improves bilirubin but not albumin in primary biliary cirrhosis: further evidence for nonefficacy.

BACKGROUND/AIM: In randomised controlled trials (RCTs) of ursodeoxycholic acid (UDCA), although serum bilirubin is frequently reduced, its effect on disease progression and mortality is unclear. As serum albumin is an established independent prognostic marker, one might expect less deterioration of serum albumin values in a UDCA-treated group. We therefore modelled the typical evolution of serum bilirubin and albumin levels over time in UDCA-untreated patients and compared it with the observed levels in UDCA RCTs. METHODS: Multilevel modelling was used to relate the evolution of serum albumin to serum bilirubin and time since patient referral. For each considered RCT, the derived model was used to predict the relationship between final mean serum albumin and bilirubin concentration, adjusted for mean serum albumin at referral and followup duration. RESULTS: Five RCTs were eligible in terms of available data, of which two had long followup. In all trials, serum albumin did not significantly differ between UDCA- and placebo-treated patients, despite the UDCA effect on serum bilirubin. Therefore, there is no evidence over time for changes or maintenance of albumin levels for UDCA-treated patients above the levels predicted for placebo-treated patients. CONCLUSIONS: Our findings suggest that UDCA does not alter serum albumin in a way that is consistent with its effect on serum bilirubin. Therefore, reductions in serum bilirubin of UDCA-treated PBC do not parallel another validated and independent prognostic marker, further questioning the validity of serum bilirubin reduction with UDCA as a surrogate therapeutic marker

Adipokines in Nonalcoholic Steatohepatitis: From Pathogenesis to Implications in Diagnosis and Therapy

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome and can vary from benign steatosis to end-stage liver disease. The pathogenesis of non-alcoholic steatohepatitis (NASH) is currently thought to involve a multiple-hit process with the first hit being the accumulation of liver fat which is followed by the development of necroinflammation and fibrosis. There is mounting evidence that cytokines secreted from adipose tissue, namely, adipokines, are implicated in the pathogenesis and progression of NAFLD. In the current review, we explore the role of these adipokines, particularly leptin, adiponectin, resistin, tumor necrosis factor-a, and interleukin-6 in NASH, as elucidated in experimental models and clinical practice. We also comment on their potential use as noninvasive markers for differentiating simple fatty liver from NASH as well as on their potential future therapeutic role in patients with NASH

Portal hypertension in patients with nonalcoholic fatty liver disease: Current knowledge and challenges

Portal hypertension (PH) has traditionally been observed as a consequence of significant fibrosis and cirrhosis in advanced non-alcoholic fatty liver disease (NAFLD). However, recent studies have provided evidence that PH may develop in earlier stages of NAFLD, suggesting that there are additional pathogenetic mechanisms at work in addition to liver fibrosis. The early development of PH in NAFLD is associated with hepatocellular lipid accumulation and ballooning, leading to the compression of liver sinusoids. External compression and intra-luminal obstacles cause mechanical forces such as strain, shear stress and elevated hydrostatic pressure that in turn activate mechanotransduction pathways, resulting in endothelial dysfunction and the development of fibrosis. The spatial distribution of histological and functional changes in the periportal and perisinusoidal areas of the liver lobule are considered responsible for the pre-sinusoidal component of PH in patients with NAFLD. Thus, current diagnostic methods such as hepatic venous pressure gradient (HVPG) measurement tend to underestimate portal pressure (PP) in NAFLD patients, who might decompensate below the HVPG threshold of 10 mmHg, which is traditionally considered the most relevant indicator of clinically significant portal hypertension (CSPH). This creates further challenges in finding a reliable diagnostic method to stratify the prognostic risk in this population of patients. In theory, the measurement of the portal pressure gradient guided by endoscopic ultrasound might overcome the limitations of HVPG measurement by avoiding the influence of the pre-sinusoidal component, but more investigations are needed to test its clinical utility for this indication. Liver and spleen stiffness measurement in combination with platelet count is currently the best-validated non-invasive approach for diagnosing CSPH and varices needing treatment. Lifestyle change remains the cornerstone of the treatment of PH in NAFLD, together with correcting the components of metabolic syndrome, using nonselective beta blockers, whereas emerging candidate drugs require more robust confirmation from clinical trials

The role of gut barrier dysfunction in postoperative complications in liver transplantation: pathophysiological and therapeutic considerations

Purpose: Gut barrier dysfunction is a pivotal pathophysiological alteration in cirrhosis and end-stage liver disease, which is further aggravated during and after the operational procedures for liver transplantation (LT). In this review, we analyze the multifactorial disruption of all major levels of defense of the gut barrier (biological, mechanical, and immunological) and correlate with clinical implications. / Methods: A narrative review of the literature was performed using PubMed, PubMed Central and Google from inception until November 29th, 2023. / Results: Systemic translocation of indigenous bacteria through this dysfunctional barrier contributes to the early post-LT infectious complications, while endotoxin translocation, through activation of the systemic inflammatory response, is implicated in non-infectious complications including renal dysfunction and graft rejection. Bacterial infections are the main cause of early in-hospital mortality of LT patients and unraveling the pathophysiology of gut barrier failure is of outmost importance. / Conclusion: A pathophysiology-based approach to prophylactic or therapeutic interventions may lead to enhancement of gut barrier function eliminating its detrimental consequences and leading to better outcomes for LT patients

Donor-recipient HLA-A mismatching is associated with hepatic artery thrombosis, sepsis, graft loss and reduced survival after liver transplantation

HLA matching is not routinely performed for liver transplantation as there is no consistent evidence of benefit, however the impact of HLA mismatching remains uncertain. We explored the effect of class I and II HLA mismatching on graft failure and mortality. 1042 liver transplants performed at a single centre, between 1999 and 2016 with available HLA typing data were included. Median follow up period was 9.38 years (IQR 4.9-14) and 350/1042 (33.6%) transplants resulted in graft loss and 280/1042 (26.9%) in death. Graft loss and mortality were not associated with the overall number of mismatches at HLA-A, -B, -C, -DR and -DQ loci. However, graft failure and mortality were both increased in the presence of one (p = 0.004 and p = 0.01) and two (p = 0.01 and p = 0.04) HLA-A mismatches. Elevated hazard ratios for graft failure and death were observed with HLA-A mismatches in univariate and multivariate Cox proportional hazard models. Excess graft loss with HLA-A mismatch (138/940 (14.7%) of mismatched compared to 6/102 (5.9%) matched transplants) occurred within the first-year following transplantation (OR 2.75, p = 0.02). Strikingly, all grafts lost due to hepatic artery thrombosis were in HLA-A mismatched transplants (31/940 vs. 0/102), as were those lost due to sepsis (35/940 vs. 0/102). In conclusion, HLA-A mismatching was associated with increased graft loss and mortality. The poorer outcome for The HLA mismatched group was due to hepatic artery thrombosis and sepsis and these complications occurred exclusively with HLA-A mismatched transplants. This suggests that HLA-A mismatching is important for post-transplant outcomes and knowledge of HLA-A status may enable enhanced surveillance and interventions to reduce risk of complications or stratified HLA-A matching in high-risk recipients

Monocyte-macrophage activation is associated with nonalcoholic fatty liver disease and liver fibrosis in HIV monoinfection independently of the gut microbiome and bacterial translocation

Background: Nonalcoholic fatty liver disease (NAFLD) is common among people living with HIV. There are limited data available on the pathophysiology of NAFLD and the development of fibrosis in this population. Objectives: The aim of this study was to investigate the association of bacterial translocation, adipose tissue dysfunction, monocyte activation and gut dysbiosis in patients with HIV monoinfection and NAFLD. Methods: Cases with biopsy-proven NAFLD and HIV monoinfection were age and sexmatched to HIV-positive and HIV-negative controls. Markers of bacterial translocation [lipopolysaccharide-binding protein (LBP), bacterialDNAand lipopolysaccharide (LPS)], adipose tissue dysfunction (leptin, adiponectin) and monocyte activation (sCD14 and sCD163) were measured by ELISA. Hepatic patterns of macrophage activation were explored with immunohistochemistry. 16 s rRNA sequencing was performed with stool. Results: Thirty-three cases were included (F2 fibrosis n¼16), matched to HIV-positive (n¼29) and HIV-negative (n¼17) controls. Cases with NAFLD were more obese (BMI 31.04.4 vs. 24.12.8 kg/m2, P<0.001) and had significantly increased levels of sCD14, sCD163 and higher leptin to adiponectin ratio vs. HIV-positive controls. Cases with F2 verse