NAFLD and autoimmune hepatitis: Do not judge a book by its cover

Helicobacter mastomyrinus infection induces autoimmune hepatitis in mice

Background

Autoimmune hepatitis (AIH) is a chronic progressive liver disease caused by the immune system mistakenly attacking its own hepatocytes. The role of the gut microbiome in the pathogenesis and progression of AIH is of considerable significance. However, the dearth of suitable animal models has significantly constrained advancements in the pathogenesis and the development of therapeutic strategies for AIH. Helicobacter mastomyrinus (H. mastomyrinus, Hm) is a potentially zoonotic pathogenic microorganism capable of causing diseases of the enterohepatic system in rodent laboratory animals. Nevertheless, research on its role and mechanisms in causing liver disease is severely limited.

Methods

In this study, male BALB/c mice were infected with Hm isolate Hm-17, and were sacrificed at 4 w, 8 w, 14 w and 22 w after infection, respectively. The serum was collected for detecting a number of AIH indicators, including the aminotransferases level, IgG content and autoantibody level. Additionally, the liver tissue was examined for pathological analysis, fibrosis, bacterial content, and the distribution of immune cells.

Results

It was observed that the infection initially caused focal necrotizing hepatitis and subsequently progressed to interface hepatitis with lymphocyte/plasma cell infiltration, as well as hypergammaglobulinemia and autoantibody reactions, predominantly to Anti-nuclear and anti-smooth muscle antibodies. Furthermore, as the infection persisted, the mice exhibited a progressive increase in liver fibrosis and mild steatosis. Despite the maintenance of a low level of Hm colonization in the liver, there was a notable infiltrate of macrophages, T and B lymphocytes. In particular, the inflammatory foci in the Hm-infected liver were highly enriched for IL17+ cells.

Conclusion

The present study provides an animal model of immunological liver injury induced by Hm infection that exhibits main characteristics similar to those observed in AIH-1 patients. This model may serve as a novel animal model for the study of the pathogenesis and potential therapeutic strategies for human AIH.

Activated Immune and Complement C3 Are Potential Contributors in MASH via Stimulating Neutrophil Extracellular Traps

The number of metabolic dysfunction-associated steatotic liver disease (MASLD) patients is increasing rapidly. More attention has been paid to the relationship between immunity and MASLD. This study explored the roles of serum autoantibodies, immunoglobulins, and complements in MASLD. A total of 182 MASLD patients were investigated and grouped by autoantibody or NAS scores. Correlation between immunology and clinical features was assessed. In addition, metabolic dysfunction-associated steatohepatitis (MASH) models were constructed to verify the findings. Neutrophils were isolated from mice and treated with complement C3 to investigate the association between C3 and neutrophil extracellular traps (NETs). IgG, IgM, and NAS scores in the autoantibody positive group were significantly higher than those in the autoantibody negative group. Antinuclear antibodies (ANA), IgA, IgE, IgG, C3, C4, ALT, and AST were related to MASH. Meanwhile, IgA and C3 correlated with the severity of MASLD. The ROC curve showed that IgA > 2.990 g/L or C3 > 1.115 g/L predicted the presence of MASH. More importantly, IgG, activated C3, and NETs were increased in MASH. C3 stimulation directly induced NET formation in the neutrophils. Immunity systems were activated in MASH and elevated IgG activated C3 to stimulate the production of NETs, thus exacerbating MASH.

EASL Clinical Practice Guidelines on the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic liver disease of unknown aetiology which may affect any patient irrespective of age, sex, and ethnicity. At baseline, the clinical spectrum of the disease varies largely from asymptomatic cases to acute liver failure with massive hepatocyte necrosis. The aim of these EASL guidelines is to provide updated guidance on the diagnosis and management of AIH both in adults and children. Updated guidance on the management of patients with variants and specific forms of AIH is also provided, as is detailed guidance on the management of AIH-associated cirrhosis, including surveillance for portal hypertension and hepatocellular carcinoma, as well as liver transplantation in decompensated cirrhosis.

Histopathology of Autoimmune Hepatitis: An Update

Autoimmune hepatitis (AIH) is a rare immune-mediated chronic liver disease that is diagnosed based on a combination of biochemical, immunologic, and histologic features and the exclusion of other causes of liver disease. According to the new consensus criteria of the International Autoimmune Hepatitis Pathology Group (IAIHPG), the likely histologic features include a chronic hepatitis pattern of injury with a lymphoplasmacytic portal infiltrate, interface activity, and portal-based fibrosis. More than mild lobular hepatitis with any of the above features can also be diagnosed as likely AIH in the absence of features of another liver disease. Centrilobular injury with prominent hepatocellular necrosis and mononuclear inflammation may represent an acute-onset disease and indicate possible AIH in the absence of concurrent liver disease. Kupffer cell hyaline bodies and portal lymphocyte apoptosis are significantly associated with AIH, whereas emperipolesis and hepatocellular rosette formation are nonspecific features indicative of disease severity. Liver histology is an integral part of the clinical diagnostic scoring system and is required to confirm or support AIH diagnosis. Substitution of the histologic component of the simplified AIH scoring system with the consensus IAIHPG criteria has been proposed to optimize clinical diagnosis. This review explores the significant role of histopathology in AIH by analyzing its main features and current histologic diagnostic criteria, different AIH presentations, differential diagnosis, assessment of concurrent liver disease, and identification of AIH variants with primary cholangiopathy.

Diagnostic performance of FibroTest-ActiTest, transient elastography, and the fibrosis-4 index in patients with autoimmune hepatitis using histological reference

BACKGROUND

Noninvasive tests are crucial for the management and follow-up of patients with autoimmune hepatitis, but their validation is limited because of insufficient data.

AIM

To investigate the diagnostic performance of three fibrosis noninvasive tests [FibroTest, vibration-controlled transient elastography (VCTE), and the fibrosis-4 index (FIB-4) and two activity biomarkers (alanine aminotransferase (ALT) and ActiTest].

METHODS

This study enrolled 103 patients for whom liver biopsy, hepatic elastography results, and laboratory markers were available. Diagnostic performance was assessed with receiver operating characteristic (ROC) curves, the Obuchowski measure (OM), and the Bayesian latent class model.

RESULTS

FibroTest and VCTE outperformed FIB-4 in cases of significant fibrosis (≥ F2), with areas under the ROC curve of 0.83 [95% confidence interval (CI): 0.73-0.90], 0.86 (95%CI: 0.77-0.92), and 0.71 (95%CI: 0.60-0.80), respectively. The mean (standard error) OM values were 0.92 (0.01), 0.93 (0.01), and 0.88 (0.02) for FibroTest, VCTE, and FIB-4, respectively; FibroTest and VCTE performed comparably, and both were superior to FIB-4 (P = 0.03 and P = 0.005). The areas under the ROC curve values for activity biomarkers were 0.86 (95%CI: 0.76-0.92) for ActiTest and 0.84 (95%CI: 0.73-0.90) for ALT (P = 0.06). The OM values for ActiTest and ALT were 0.92 (0.02) and 0.90 (0.02), respectively (P = 0.005).

CONCLUSION

FibroTest and VCTE outperformed FIB-4 according to the OM. FibroTest-ActiTest facilitated the evaluation of both fibrosis and activity.

PNPLA3 I148 M genetic variant in autoimmune hepatitis characterises advanced disease at diagnosis and reduced survival free of cirrhotic events and liver-related mortality

Background

Autoimmune hepatitis (AIH) is a relatively rare autoimmune disease with a strong genetic background. The patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148 M (rs738409 C/G) variant has been associated with hepatic inflammation and fibrosis in chronic hepatic diseases beyond metabolic dysfunction-associated steatotic liver disease (MASLD).

Aim

Our aim was to investigate the significance of PNPLA3 I148 M variant in AIH.

Method

Two hundred AIH patients, followed in our centre, were evaluated while 100 healthy subjects served as controls. Genotyping was performed with allelic discrimination end-point polymerase chain reaction (PCR).

Results

The I148 M variant was present in 95/200 (47.5 %) AIH patients compared to 47/100 (47 %) healthy controls (p = 1.000). Patients with GG/CG genotypes were more likely to present with decompensated cirrhosis at diagnosis (GG/CG 6.3 % vs. CC 1 %, p = 0.039). Comorbidity with cardiometabolic risk factors and concurrence of MASLD was similar across genotypes. Simple steatosis was present in 37/186 (19.9 %) and steatohepatitis in 14/186 (7.5 %) patients with available liver biopsy without correlation with PNPLA3 genotype. Fibrosis stage and grade of inflammation were not correlated with any genotype. Response to treatment was also independent of the presence of the I148 M variant, even though a longer time was needed to achieve complete biochemical response in those carrying the GG/CG genotypes (p = 0.07). On Kaplan Meier analysis homozygosity for the G allele corelated with reduced survival free of decompensation (p = 0.006), cirrhotic events (decompensation, liver transplantation, hepatocellular carcinoma; p = 0.001) and liver-related death or liver transplantation (p = 0.011) in treated patients.

Conclusions

The PNPLA3 I148 M variant in AIH patients is associated with increased risk of advanced disease at diagnosis and reduced survival free of cirrhotic events and liver-related death or liver transplantation, regardless of the presence of MASLD. This signifies a potential role for the PNPLA3 I148 M variant as a new AIH biomarker allowing to identify patients at increased risk of disease progression.

Waitlist and transplant outcomes in patients with metabolic dysfunction‐associated steatotic liver disease and autoimmune hepatitis

Background and Aims

Metabolic dysfunction‐associated steatotic liver disease (MASLD), in the context of autoimmune hepatitis (AIH) among liver transplantation (LT) candidates or recipients remains poorly understood. This study compares waitlist and post‐LT outcomes in patients with MASLD/AIH to MASLD and AIH alone.

Methods

Using the united network organ sharing database (2002–2022), we compared waitlist outcomes and post‐LT survival among patients with MASLD/AIH (n = 282), AIH (n = 5812), and MASLD (n = 33 331). Competing risk, Kaplan Meier estimates and Cox proportional hazard analyses were performed.

Results

MASLD/AIH group had the highest rates of encephalopathy and ascites, and highest MELD scores. MASLD/AIH patients had higher transplantation incidence (adjusted subdistribution hazard ratio [aSHR] 1.64, 95% CI 1.44–1.85; p < .001) and lower waitlist removal risk (aSHR .30, 95% CI .20–.44; p < .001) compared to MASLD alone. One‐year post‐LT survival favoured MASLD compared to AIH (patient: 92% vs. 91%, p < .001; graft: 89% vs. 88%, p < .001) and MASLD/AIH (patient: 92% vs. 90%, p = .008; graft: 89% vs. 88%, p = .023). Recipients with MASLD/AIH showed no significant difference in survival at 10‐year post‐LT compared to MASLD (patient: 63% vs. 61%, p = .68; graft 60% vs. 59%, p = .83) and AIH (patient: 63% vs. 70%, p = .07; graft: 60% vs. 64%, p = .42).

Conclusions

Our study showed that MASLD/AIH patients demonstrate higher LT incidence and lower dropout rates. Long‐term post‐LT outcomes did not significantly differ between groups. Further prospective multicenter studies are needed to validate these findings.

Patients With Autoimmune Hepatitis and Nonalcoholic Fatty Liver Disease: Characteristics, Treatment, and Outcomes

GOAL

The objective of this study was to characterize an autoimmune hepatitis (AIH)/nonalcoholic fatty liver disease (NAFLD) overlap cohort, determine if they received standard of care treatment, and delineate their outcomes in comparison with patients with AIH or NAFLD alone.

BACKGROUND

AIH is a relatively rare and heterogeneously presenting liver disease of unknown etiology. NAFLD is a leading cause of liver disease worldwide. AIH treatment includes steroids, which have adverse metabolic effects that can worsen NAFLD. No treatment guidelines are available to mitigate this side on AIH/NAFLD overlap patients. Few studies to date have examined these patients' characteristics, management practices, and outcomes.

MATERIALS AND METHODS

A single-center, retrospective chart review study examining biopsy-proven AIH/NAFLD, AIH, and NAFLD patients. Characteristics, treatment, and 1- and 3-year outcomes (all-cause mortality, need for liver transplantation, or decompensated cirrhosis) were evaluated.

RESULTS

A total of 72 patients (36.1% AIH/NAFLD, 34.7% AIH, and 29.2% NAFLD) were included. AIH/NAFLD patients were found to be more often Hispanic/Latino, female, and with lower liver aminotransaminases, immunoglobulin G, and anti-smooth muscle antibody positivity. AIH/NAFLD patients were less likely to receive standard of care treatment. No significant differences in outcomes were seen between AIH/NAFLD and either AIH or NAFLD.

CONCLUSIONS

Our study demonstrated that AIH/NAFLD patients have unique characteristics and are less likely to receive standard of care treatment compared with patients with AIH alone. Despite this, no difference in outcomes (all-cause mortality, need for liver transplantation, or decompensated cirrhosis) was seen. Given NAFLD's rising prevalence, AIH/NAFLD cases will likely increase, and may benefit from alternative treatment guidelines to prevent worsening of NAFLD.

Prognostic models and autoimmune liver diseases

Autoimmune liver diseases (AILDs) are complex diseases with unknown causes and immune-mediated pathophysiology. In primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) disease modifying drugs are available which improve patient quality and quantity of life. In primary sclerosing cholangitis (PSC) no medical therapy is available and the only accepted treatment is liver transplantation (LT). PBC, PSC and AIH possess features that describe the archetype of patients within each disorder. On the other hand, the classical disorders are not homogeneous, and patients within each diagnosis may present with a range of clinical, biochemical, serological, and histological findings. Singularly, they are considered rare diseases, but together, they account for approximately 20% of LTs in Europe and USA. Management of these patients is complex, as AILDs are relatively uncommon in clinical practice with challenges in developing expertise, disease presentation can be sneaky, clinical phenotypes and disease course are heterogeneous. Prognostic models are key tools for clinicians to assess patients' risk and to provide personalized care to patients. Aim of this review is to discuss challenges of the management of AILDs and how the available prognostic models can help. We will discuss the prognostic models developed in AILDs, with a special focus on the prognostic models that can support the clinical management of patients with AILDs: in PBC models based on ursodeoxycholic acid (UDCA) response and markers of liver fibrosis; in PSC several markers including biochemistry, disease stage and radiological semiquantitative markers; and finally in AIH, markers of disease stage and disease activity.

Accuracy of controlled attenuation parameter measurement for the detection of steatosis in autoimmune liver diseases

Background & Aims

Concurrent fatty liver disease represents an emerging challenge in the care of individuals with autoimmune liver diseases (AILD). Therefore, we aimed to validate the ultrasound-based method of controlled-attenuation parameter (CAP) as a non-invasive tool to detect hepatic steatosis in individuals with AILD.

Methods

The diagnostic performance of CAP to determine biopsy-proven hepatic steatosis (>5%) was assessed in individuals with AILD (autoimmune hepatitis [AIH], primary biliary cholangitis [PBC], primary biliary cholangitis [PSC], or variant syndromes) who underwent liver biopsy at the University Medical Center Hamburg-Eppendorf between 2015-2020 by calculating the area under the receiver operating characteristic (AUROC) curves. In AIH, the impact of disease activity was evaluated by assessment of CAP upon resolution of hepatic inflammation during follow-up.

Results

Overall, 433 individuals with AILD (AIH: 218, PBC: 51, PSC: 85, PBC/AIH: 63, PSC/AIH: 16) were included. Histologically proven steatosis was present in 90 individuals (20.8%). Steatosis was less frequently observed in people with PSC (14%) than in other AILD. CAP values correlated positively with grade of steatosis (ρ = 0.39) and the BMI (ρ = 0.53). In PBC and PSC, the ROC curves defined an AUROC of 0.81 and 0.93 for detecting steatosis at an optimal cut-off of 276 dB/m (sensitivity: 0.71; specificity: 0.82) and 254 dB/m (sensitivity: 0.91, specificity: 0.85), respectively. In AIH, the diagnostic performance of CAP was significantly lower (AUROC = 0.72, p = 0.009). However, resolution of hepatic inflammation under treatment was associated with a significant increase in CAP levels (median [IQR]: +38.0 [6-81] dB/m) and considerably improved diagnostic accuracy (AUROC = 0.85; cut-off: 288 dB/m; sensitivity: 0.67, specificity: 0.90).

Conclusions

In PBC and PSC, hepatic steatosis can be reliably detected by applying disease-specific thresholds of CAP. In AIH, the diagnostic accuracy of CAP is moderate at diagnosis, but improves after acute hepatitis has resolved.

Impact and implications

Non-invasive estimation of fat content in the liver can be performed with the ultrasound-based method of controlled-attenuation parameter (CAP). Here, we showed that the presence of a concomitant fatty liver is frequent in people with autoimmune liver diseases and we determined disease-specific thresholds of CAP to best predict the presence of a fatty liver. CAP measurement was shown to be a valid tool to detect fatty liver in individuals with PSC and PBC; however, in AIH, CAP had limited accuracy especially when significant inflammatory activity was present in the liver. In the context of substantial liver inflammation, therefore, CAP values should be interpreted with caution, and measurements should be repeated after acute hepatitis has resolved.

Autoimmune liver diseases and diabetes

Autoimmune liver diseases include autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. They are chronic, heterogenous diseases affecting the liver which is a key metabolic organ that ensures glucose homeostasis. It is well known that patients with other chronic liver diseases such as cirrhosis and nonalcoholic fatty liver disease (NAFLD) display glucose disturbances like insulin resistance and have an increased risk of diabetes. Previous evidence on glucose disturbances in patients with autoimmune liver disease is scarce but does point towards a potentially increased risk of type 1 diabetes and type 2 diabetes. The underlying mechanisms are unknown but may reflect genetic predisposition, concurrent NAFLD and or cirrhosis development, and treatment (steroid) related impairment of glucose homeostasis. Therefore, increased awareness and surveillance of diabetes development in patients with autoimmune liver disease may be important. Overall, detection and treatment of diabetes generally follow the usual diabetes guidelines; however, in patients with advanced liver cirrhosis, HbA1c may not be a reliable marker of average glucose levels, and treatment with insulin is generally recommended. In addition, it has recently been suggested that sodium-glucose cotransporter 2 inhibitors may be beneficial in treating refractory ascites. Further research on diabetes risk in autoimmune liver disease is warranted.

Treatment responses and outcomes in patients with autoimmune hepatitis and concomitant features of non-alcoholic fatty liver disease

Background & Aims

Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) affect 17-46% of Western countries, making coexistence with other liver diseases inevitable. We investigated the prevalence and clinical significance of NAFLD/NASH or the components of metabolic syndrome (MetS) in a large multicentric cohort of patients with autoimmune hepatitis (AIH).

Methods

Data from six academic centres (Greece, Canada, Japan, Germany, The Netherlands, and Spain) were evaluated. The presence of NAFLD/NASH in liver biopsy, MetS components, and clinical and laboratory parameters were recorded.

Results

A total of 640 patients (474 females, age 49 [4-87] years; follow-up 78 [1-521] months) were included. NAFLD was present in 146 (22.8%) patients (AIH/non-alcoholic fatty liver [NAFL] 115 [18%], AIH/NASH 31 [4.8%]). AIH/NAFL patients were older (p = 0.017), more frequently overweight or obese (p = 0.002), had hypertension (p = 0.001), and had diabetes (p = 0.016), whereas they less frequently had acute presentation (p = 0.002) and soluble liver antigen/liver pancreas positivity (p <0.05), lower transaminases (p <0.001), ALP (p = 0.028) and IgG (p = 0.004) and higher albumin (p <0.001) than patients with AIH only. Patients with AIH/NASH more frequently had cirrhosis at diagnosis (p = 0.036) and higher IgG (p = 0.009). Response to treatment did not differ between groups. Patients with cirrhosis with AIH/NAFL had higher frequency of decompensation compared with patients with AIH only (p <0.05). Patients with type 2 diabetes mellitus and dyslipidaemia had increased hazard of disease progression (p <0.05 for each).

Conclusions

The prevalence of NAFLD in AIH is similar to the general population. Concurrence of NASH in patients with AIH signifies a more severe disease, whereas that of NAFL may indicate a worse prognosis in patients with cirrhosis. T2DM and dyslipidaemia in AIH patients are associated with dismal parameters of outcome. Our findings suggest that NAFLD presence or even components of MetS in patients with AIH may affect prognosis, so closer follow-up of such patients is warranted.

Impact and implications

Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) affect many people, making coexistence with other liver diseases inevitable. We investigated the prevalence and clinical significance of NAFLD/NASH or the components of metabolic syndrome (MetS) in patients with autoimmune hepatitis (AIH). NAFLD and NASH presence in patients with AIH is as frequent as in the general population. The concurrence of NASH in patients with AIH seems to signify a more severe disease, whereas that of non-alcoholic fatty liver may indicate a worse prognosis in a specific subgroup of patients who already have cirrhosis at diagnosis. Diabetes or dyslipidaemia in patients with AIH were associated with worse prognosis. Therefore, it seems that closer follow-up of patients with concurrent AIH and NAFLD or AIH and components of MetS is needed.

Distinguishing Autoimmune Hepatitis From Steatohepatitis in Adolescents With Obesity and Positive Screening Alanine Aminotransferase

Screening children with obesity for nonalcoholic fatty liver disease leads to identification of elevated alanine aminotransferase (ALT) and is a common cause for referral to pediatric gastroenterology. Guidelines recommend that children with positive screening ALT be evaluated for causes of ALT elevation beyond nonalcoholic fatty liver disease. One clinical challenge is that autoantibodies can be present in patients with obesity and thus may or may not represent autoimmune hepatitis. This case series highlights the importance of a comprehensive evaluation to reach an accurate diagnosis.

Autoimmune serology testing in clinical practice: An updated roadmap for the diagnosis of autoimmune hepatitis

Diagnosis of autoimmune hepatitis (AIH) is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the disease. The clinical spectrum of AIH varies from completely asymptomatic to acute-severe or even rarely fulminant hepatic failure, while everybody can be affected irrespective of age, gender, and ethnicity. The old revised and the newer simplified diagnostic scores have been established by the International Autoimmune Hepatitis Group (IAIHG) in 1999 and 2008, respectively, which are based on several clinical, laboratory and histological parameters. Additionally, a thorough differential diagnosis from other diseases mimicking AIH is absolutely indicated. In this context, autoantibodies detection in patients with suspected AIH is mandatory -even though not pathognomonic- not only for AIH diagnosis but furthermore, for AIH classification (AIH-type 1 and AIH-type 2). Although autoimmune serology can be supportive of AIH diagnosis in ≥95% of cases if testing has been performed according to the IAIHG guidelines, this is not the case under real-life circumstances in routine clinical laboratories. Clinicians should be careful both for the importance of the required testing and how to interpret the results and therefore, they should communicate and discuss with the laboratory personnel to achieve the maximum benefit for the patient. Herein, a detailed and updated review of the diagnostic work-up for AIH diagnosis under real-life conditions is given to minimize the underestimation and misdiagnosis of AIH which can result in progression of the disease and unfavourable outcomes.

Impact of hepatic steatosis on treatment response of autoimmune hepatitis: A retrospective multicentre analysis

Background

There is a paucity of data on whether steatosis impacts autoimmune hepatitis (AIH) treatment response. We aimed to evaluate the influence of baseline steatosis on the biochemical response, fibrosis progression, and adverse longterm outcomes of AIH.

Methods

Steatosis was diagnosed by a controlled attenuation parameter (CAP) ≥ 248 dB / m. Only patients who underwent immunosuppressive therapy with available liver histological material at diagnosis and qualified CAP within seven days of the liver biopsy were included. Univariate and multivariate analyses were subsequently conducted.

Results

The multicentre and retrospective cohort enrolled 222 subjects (88.3% female, median age 54 years, median follow-up 48 months) in the final analysis, and 56 (25.2%) patients had hepatic steatosis. Diabetes, hypertension, and significant fibrosis at baseline were more common in the steatosis group than in the no steatosis group. After adjusting for confounding factors, hepatic steatosis was an independent predictor of insufficient biochemical response (OR: 8.07) and identified as an independent predictor of long-term adverse outcomes (HR: 4.07). By subgroup multivariate analysis (different degrees of steatosis, fibrosis, and prednisone dose), hepatic steatosis independently showed a relatively stable correlation with treatment response. Furthermore, in contrast to those without steatosis, a significant increase in liver stiffness (LS) was observed in patients with steatosis (4.1%/year vs. -16%/year, P < 0.001).

Conclusions

Concomitant hepatic steatosis was significantly associated with poor response to treatment in AIH patients. Routine CAP measurements are therefore essential to guide the management of AIH.

Role of B Lymphocytes in the Pathogenesis of NAFLD: A 2022 Update

Non-alcoholic fatty liver disease and its related complications are becoming one of the most important health problems globally. The liver functions as both a metabolic and an immune organ. The crosstalk between hepatocytes and intrahepatic immune cells plays a key role in coordinating a dual function of the liver in terms of the protection of the host from antigenic overload as a result of receiving nutrients and gut microbiota antigenic stimulation via facilitating immunologic tolerance. B cells are the most abundant lymphocytes in the liver. The crucial role of intrahepatic B cells in energy metabolism under different immune conditions is now emerging in the literature. The accumulating evidence has demonstrated that the antibodies and cytokines produced by B cells in the microenvironment play key and distinct roles in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Herein, we have aimed to consolidate and update the current knowledge about the pathophysiological roles of B cells as well as the underlying mechanisms in energy metabolism. Understanding how B cells can exacerbate and suppress liver damage by exploiting the antibodies and cytokines they produce will be of great importance for designing B-cell targeting therapies to treat various liver diseases.

Prevalence and Significance of Antinuclear Antibodies in Biopsy-Proven Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Aim

Associations between antinuclear antibodies (ANAs) and disease severity in nonalcoholic fatty liver disease (NAFLD) remain unclear. This study aimed to provide reliable estimates of ANA prevalence in subjects with biopsy-proven NAFLD and to investigate whether its associations with liver disease severity were established.

Methods

Observational studies measuring ANA in NAFLD patients were derived from the PubMed, Embase, and Web of Science databases from inception to March 30, 2022. The effect size was presented as the pooled risk difference, unstandardized mean differences (MDs), and odds ratio (OR) with a 95% confidence interval (CI).

Results

Thirteen articles involving 2331 patients were finally included. Among the subjects with biopsy-proven NAFLD, the overall prevalence of ANA positivity was high as 23% (95% CI: 19%-28%), but there were no statistically significant differences between ANA-positive and ANA-negative NAFLD patients in the levels of liver enzymes and blood lipids, grades of hepatocellular ballooning, lobular and portal inflammation, or risks of moderate-severe steatosis and significant fibrosis. However, the subgroup analysis showed that different geographic regions led to diverse results. ANA positivity was associated with a significantly elevated risk of significant fibrosis in the Eastern population (OR = 2.30, 95% CI: 1.30-4.06) but not in the Western population (OR = 1.00, 95% CI: 0.54-1.83).

Conclusions

Serum ANA was present in approximately one-quarter of subjects with biopsy-proven NAFLD, but it conferred a greater risk of significant fibrosis only in Eastern but not Western populations.

Explore the Mechanism of Astragalus mongholicus Bunge against Nonalcoholic Fatty Liver Disease Based on Network Pharmacology and Experimental Verification

Objective

Astragalus mongholicus Bunge [Fabaceae] (AMB), a traditional Chinese medicine (TCM), has been widely used to treat liver diseases in the clinic. However, the efficacy and mechanism of AMB in the treatment of nonalcoholic fatty liver disease (NAFLD) remain unclear. The purpose of this study was to systematically investigate the active components and mechanisms of AMB against NAFLD based on network pharmacology, molecular docking, and experimental verification.

Methods

First, the bioactive components and relevant targets of AMB were screened from the Traditional Chinese Medicine Systematic Pharmacology (TCMSP) database, and NAFLD-related targets were obtained from the GeneCards database. Then, the AMB-NAFLD protein target interaction network was built by the STRING database. GO and KEGG pathway enrichment analyses were performed using the DAVID database. The component targets were visualized using Cytoscape software. Finally, molecular docking and experiments were used to verify the results of network pharmacological prediction.

Results

Network pharmacology predicted that quercetin may be the main active component in AMB, and the TNF and MAPK signaling pathways may be the key targets of AMB against NAFLD. Molecular docking validation results demonstrated that quercetin, as the main active component of AMB, had the highest binding affinity with TNF. Furthermore, quercetin played a distinct role in alleviating NAFLD through in vitro experiments. Quercetin upregulated the phosphorylation levels of AMPK and inhibited the expression of p-MAPK and TNF-α. In addition, we further discovered that quercetin could increase ACC phosphorylation and CPT1α expression in PA-induced HepG2 cells.

Conclusions

Our results indicated that quercetin, as the main active component in AMB, exerts an anti-NAFLD effect by regulating the AMPK/MAPK/TNF-α and AMPK/ACC/CPT1α signaling pathways to inhibit inflammation and alleviate lipid accumulation.

Autoimmune Hepatitis: Serum Autoantibodies in Clinical Practice

Circulating autoantibodies are a key diagnostic tool in autoimmune hepatitis (AIH), being positive in 95% of the cases if tested according to dedicated guidelines issued by the International Autoimmune Hepatitis Group. They also allow the distinction between type 1 AIH, characterized by positive anti-nuclear and/or anti-smooth muscle antibody, and type 2 AIH, characterized by positive anti-liver kidney microsomal type 1 and/or anti-liver cytosol type 1 antibody. Anti-soluble liver antigen is the only AIH-specific autoantibody, and is found in 20-30% of both type 1 and type 2 AIH. Anti-neutrophil cytoplasmic antibody is frequently positive in type 1 AIH, being associated also with inflammatory bowel disease and with primary/autoimmune sclerosing cholangitis. The reference method for autoantibody testing remains indirect immunofluorescence on triple tissue (rodent liver, kidney and stomach), allowing both the detection of the majority of liver-relevant reactivities, including those autoantibodies whose molecular target antigens are unknown. Of note, the current knowledge of the clinical significance of autoantibodies relies on studies based on this technique. However, immunofluorescence requires trained laboratory personnel, is observer-dependent, and lacks standardization, leading to ongoing attempts at replacing this method with automated assays, the sensitivity, and specificity of which, however, require further studies before they can be used as a reliable alternative to immunofluorescence; currently, they may be used as complementary to immunofluorescence.

Network Pharmacology-Based Analysis of Pogostemon cablin (Blanco) Benth Beneficial Effects to Alleviate Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and is associated with high morbidity and mortality. Pogostemon cablin (Blanco) Benth/Huo Xiang (HX) is a perennial herb with unique anti-oxidant and anti-inflammatory properties, and thus, can positively affect liver function. In this study, we used network pharmacology to predict the potential mechanism of HX on NAFLD. Pharmacological experiments were used to verify the effect of HX on the functions of NAFLD. Network pharmacology identified nine components that interacted with 82 NAFLD-related targets, revealing four target genes: TNF, IL6, TP53, and AKT1. HX prevents the development and progression of NAFLD through different pathways and targets with quercetin-regulated lipid metabolism, anti-inflammatory, and anti-oxidant pathways playing an essential role in the treatment of NAFLD. Compared with feeding HFD, HX significantly attenuated lipid accumulation in vivo with mice and also in vitro with mouse liver cells. A high dose of HX decreased hepatocyte lipid accumulation and the abundance of SREBF1 and FASN. Validation experiments revealed that HX inhibited the activation of NF-κB/IκB signaling and decreased the release and levels of pro-inflammatory factors (TNF-α and IL-6). These data suggest that HX can attenuate abnormal lipid metabolic responses and enhance antioxidant mechanisms. Thus, the pharmacological effects from plants used in traditional Chinese medicine are achievde through a multi-level response.

Metabolic-associated fatty liver disease and autoimmune hepatitis: an overlooked interaction

INTRODUCTION

Metabolic-associated fatty liver disease (MAFLD) is the most common liver disease globally, and affects about a quarter of the general population. Autoimmune hepatitis (AIH) is a severe (sometimes fatal) liver disease that affects children and adults, with a rising prevalence. Thus, not surprisingly, both conditions can frequently coexist, with potential synergistic impact on the course of the disease and response to therapy of both entities.

AREAS COVERED

In this work, the authors aimed to provide a narrative updated review on this interaction, diagnosis, and management of MAFLD/AIH and the current challenges.

EXPERT OPINION

Clarifying the nature of the complex interaction between the two diseases was hampered by a myriad of factors, particularly the previous diagnosis of exclusion for fatty liver disease associated with metabolic dysfunction. The recent redefinition of fatty liver disease that led to the development of positive diagnostic criteria for MAFLD has the premise to help in circumventing some of these challenges.

Programmed cell death-1 rs11568821 and interleukin-28B rs12979860 polymorphisms in autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis (AIH) is a relatively rare chronic liver disease of unknown etiology. The genetic background affects susceptibility, clinical phenotype, and prognosis. The programmed cell death-1 rs11568821 polymorphism (PD1.3) has been associated with susceptibility to autoimmune diseases. The interleukin-28B (IL28B) rs12979860 polymorphism has been associated with steatosis, inflammation, and fibrosis in liver diseases.

AIM

Our aim was to investigate for the first time the incidence and clinical significance of PD1.3 and IL28B rs12979860 in AIH.

METHODS

Two hundred patients with AIH were evaluated, while 100 healthy subjects were used as controls. Genotyping was performed with in-house allelic discrimination End-Point PCR.

RESULTS

The SNP PD1.3/A was present in 36/200 (18%) AIH patients compared to 28/100 (28%) healthy controls (p = 0.065). The AA/GA genotypes were not associated with the mode of presentation of AIH, the histological grade or stage, the presence of cirrhosis, risk of disease progression, response to treatment and survival. The IL28B rs12979860 genotype distribution was CC 79/200 (39.5%), TT 36/200 (18%) and CT 85/200 (42.5%), in similar rates with healthy controls (p = 0.878). Inflammatory activity and fibrosis stage did not differ between CC homozygotes and CT/TT carriers. LDL cholesterol was significantly higher in CC than CT/TT patients (P = 0.027), though no differences was found regarding the presence of steatosis or steatohepatitis. On-treatment response to immunosuppressive treatment was not affected by the IL28B rs12979860 polymorphism. However, CC homozygotes AIH patients achieved treatment withdrawal in significantly higher rates (OR 2.3, 95%CI: 1.1-4.7, P = 0.02) irrespective of the presence of steatosis or steatohepatitis.

CONCLUSIONS

The PD1.3 and IL28B rs12979860 variants are unlikely to contribute to AIH susceptibility, disease presentation and prognosis. The IL28B rs12979860 is not associated with the presence of concurrent steatosis or steatohepatitis. However, although on-treatment response rates to immunosuppression were not affected by the IL28B rs12979860 polymorphism, AIH patients with CC homozygosity were more likely to achieve complete treatment withdrawal. This novel finding needs validation and further clarification from larger multicenter studies.

Current management of NAFLD/NASH

NAFLD is the most common cause of liver disease worldwide, and its prevalence is significantly increasing. Studies have shown that it is associated with comorbidities such as diabetes, metabolic syndrome and obesity. Early diagnosis and management are highly important and could modify the prognosis of the disease. Evaluating the possibility of multiple aetiologies and recognizing the additional causes of liver disease should be a part of the patient's initial assessment. There are no approved drug treatments as yet, so the main management strategies should involve lifestyle changes such as physical activity and dietary re-education.

Current Trends and Characteristics of Hepatocellular Carcinoma in Patients with Autoimmune Liver Diseases

Hepatocellular carcinoma (HCC), the commonest among liver cancers, is one of the leading causes of mortality among malignancies worldwide. Several reports demonstrate autoimmune liver diseases (AILDs), including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) to confer increased risk of hepatobiliary malignancies, albeit at lower frequencies compared to other liver diseases. Several parameters have been recognized as risk factors for HCC development in AIH and PBC, including demographics such as older age and male sex, clinical features, the most decisive being cirrhosis and other co-existing factors, such as alcohol consumption. Moreover, biochemical activity and treatment response have been increasingly recognized as prognostic factors for HCC development in AIH and PBC. As available treatment modalities are effective only when HCC diagnosis is established early, surveillance has been proven essential for HCC prognosis. Considering that the risk for HCC is not uniform between and within disease groups, refinement of screening strategies according to prevailing demographic, clinical, and molecular risk factors is mandated in AILDs patients, as personalized HCC risk prediction will offer significant advantage in patients at high and/or medium risk. Furthermore, future investigations should draw attention to whether modification of immunosuppression could benefit AIH patients after HCC diagnosis.

Alcoholic liver disease and autoimmune hepatitis: Sometimes a closer look under the surface is needed

AIMS

Differential diagnosis of autoimmune hepatitis (AIH) incorporates various liver diseases, including alcoholic liver disease (ALD). We report on clinical, laboratory and outcome characteristics of AIH patients who were initially referred as ALD based on increased alcohol consumption (AIH/ALD).

METHODS

From 2000-2019, we retrospectively identified 12 AIH/ALD patients [9 males, age: 61 (30-73) years] in our prospective data base of 317 AIH patients.

RESULTS

AIH diagnosis was based on aminotransferases elevation in 10 patients, high IgG in 8, compatible autoantibody profile in all and typical/compatible histology in all 9 with available biopsy. There were no significant differences of baseline demographics, presentation, cirrhosis at diagnosis, response to treatment and simplified score compared to 45 age- and sex-matched AIH patients without alcohol consumption and 44 age- and sex-matched ALD patients. However, the AIH/ALD cohort was characterized by more frequent progression to cirrhosis, higher liver-related deaths and overall mortality compared to AIH, though similar to the ALD group. AST/ALT ratio>1 seems to bear a good positive (0.84) and negative predictive value (0.88) for ALD and AIH diagnosis, respectively, but cannot help in discriminating the AIH/ALD variant.

CONCLUSIONS

AIH should not be forgotten in patients with alcohol use when clinical and laboratory features hint towards the diagnosis of AIH/ALD variant as this group seems to have worse outcome compared to those with AIH alone suggesting the need for closer follow-up and surveillance. Reliable autoantibody testing and cautious interpretation of liver histology appear mandatory for AIH diagnosis in these difficult to diagnose cases.

Src-mediated Tyr353 phosphorylation of IP3R1 promotes its stability and causes apoptosis in palmitic acid-treated hepatocytes

Palmitic acid (PA)-induced hepatocyte apoptosis is critical for the progression of nonalcoholic fatty liver disease (NAFLD). Inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) is an intracellular Ca²⁺-release channel and is involved in PA-induced hepatocyte apoptosis. While the expression of IP3R1 is elevated in patients with NAFLD and in hepatocytes treated with PA, it remains unclear how PA promotes the expression of IP3R1. In present study, our results showed that PA induced mitochondrial dysfunction and apoptosis, which is accompanied with the increase of the IP3R1 expression in hepatic cells. The inhibition of IP3R1 expression using siRNA ameliorated the PA-induced mitochondrial dysfunction. Furthermore, PA enhanced the stability of the IP3R1 protein instead of an increase in its mRNA levels. PA also promoted the phosphorylation of IP3R1 at the Tyr353 site and increased the phosphorylation of src in hepatic cells. Moreover, an inhibitor of src kinase (SU6656) significantly reduced the Tyr353 phosphorylation of IP3R1 and decreased its stability. In addition, SU6656 improved mitochondrial function and reduced apoptosis in hepatocytes. Conclusion: PA promotes the Tyr353 phosphorylation of IP3R1 by activating the src pathway and increasing the protein stability of IP3R1, which consequently results in mitochondrial Ca²⁺ overload and mitochondrial dysfunction in hepatic cells. Our results also suggested that inhibition of the src/IP3R1 pathway, such as by SU6656, may be a novel potential therapeutic approach for the treatment of NAFLD.

Non-alcoholic steatohepatitis or autoimmune hepatitis? Sometimes a closer look under the surface is needed

Non-alcoholic fatty liver disease (NAFLD) is nowadays the most common liver disease worldwide. Autoimmune hepatitis (AIH) is a relatively rare disease of the liver characterised by female predominance, circulating autoantibodies, polyclonal hypergammaglobulinaemia, interface hepatitis on histology and favourable response to immunosuppression. The possibility of an additional AIH diagnosis in patients with NAFLD (NAFLD/AIH concurrence) or the presence of AIH alone instead of a supposed NAFLD diagnosis represents a challenge for clinicians. We report herein two adult patients (a 33-year-old woman and a 59-year-old man) with a previous NAFLD diagnosis who proved finally to suffer from AIH alone. These two representative cases indicate how difficult and complicated could be sometimes the diagnosis of patients with AIH highlighting the range of disease manifestations and severity while they also underline that although NAFLD is by far the most frequent chronic liver disease this could not be always the case.

Non-alcoholic fatty liver disease to metabolic dysfunction-associated fatty liver disease: Conceptual changes for clinicians, researchers and patients

Non-alcoholic fatty liver disease (NAFLD) is now the most common etiology of chronic liver disease threatening global public health. However, the name "NAFLD" is no longer appropriate with the change of time. Recently, a new term, "metabolic dysfunction-associated fatty liver disease" has been proposed by an international panel of experts, which implies profound conceptual changes in terms of its metabolism-related etiology and disease heterogeneity. In this article we discuss the specific conceptual changes that clinicians, researchers and patients must absorb.