Leptin gene Polymorphism and Leptin protein levels in Pediatric Autoimmune Hepatitis.

BACKGROUND: Leptin plays a role in regulating energy balance, immunity, and inflammation. Studies suggest higher leptin levels might be associated with various autoimmune diseases. Most of them were in adult. To our knowledge, our study is one of the few that describe serum leptin level and leptin gene polymorphism in children with autoimmune hepatitis (AIH). OBJECTIVE: Our study aims to explore the association between serum leptin level and genetic variations in leptin gene with the likelihood of AIH in children. PATIENTS AND METHODS: Thirty-one children with AIH and 29 healthy children serving as a control group were included. Serum leptin levels were measured by ELISA assays. Leptin rs2167270 genotyping was done using the real time-PCR. The relationship of serum leptin level and leptin gene polymorphism with patients' data was studied. Patients follow up to assess treatment response. RESULTS: Children with AIH had significantly higher levels of leptin compared to healthy controls. GG genotype was significantly more prevalent in the AIH group compared to controls. CONCLUSION: High serum leptin levels and leptin gene polymorphism may play a role in AIH development. It is worthy to recognize if leptin can serve as diagnostic and/or therapeutic target in AIH in children.

Autoimmune hepatitis displays distinctively high multi-antennary sialylation on plasma N-glycans compared to other liver diseases.

BACKGROUND: Changes in plasma protein glycosylation are known to functionally affect proteins and to associate with liver diseases, including cirrhosis and hepatocellular carcinoma. Autoimmune hepatitis (AIH) is a liver disease characterized by liver inflammation and raised serum levels of IgG, and is difficult to distinguish from other liver diseases. The aim of this study was to examine plasma and IgG-specific N-glycosylation in AIH and compare it with healthy controls and other liver diseases. METHODS: In this cross-sectional cohort study, total plasma N-glycosylation and IgG Fc glycosylation analysis was performed by mass spectrometry for 66 AIH patients, 60 age- and sex-matched healthy controls, 31 primary biliary cholangitis patients, 10 primary sclerosing cholangitis patients, 30 non-alcoholic fatty liver disease patients and 74 patients with viral or alcoholic hepatitis. A total of 121 glycans were quantified per individual. Associations between glycosylation traits and AIH were investigated as compared to healthy controls and other liver diseases. RESULTS: Glycan traits bisection (OR: 3.78 [1.88-9.35], p-value: 5.88 × 10- 3), tetraantennary sialylation per galactose (A4GS) (OR: 2.88 [1.75-5.16], p-value: 1.63 × 10- 3), IgG1 galactosylation (OR: 0.35 [0.2-0.58], p-value: 3.47 × 10- 5) and hybrid type glycans (OR: 2.73 [1.67-4.89], p-value: 2.31 × 10- 3) were found as discriminators between AIH and healthy controls. High A4GS differentiated AIH from other liver diseases, while bisection associated with cirrhosis severity. CONCLUSIONS: Compared to other liver diseases, AIH shows distinctively high A4GS levels in plasma, with potential implications on glycoprotein function and clearance. Plasma-derived glycosylation has potential to be used as a diagnostic marker for AIH in the future. This may alleviate the need for a liver biopsy at diagnosis. Glycosidic changes should be investigated further in longitudinal studies and may be used for diagnostic and monitoring purposes in the future.

Increased IgD and CD27 Double Negative (DN) B cell population in pediatric onset autoimmune hepatitis.

Autoimmune hepatitis (AIH) is a chronic, inflammatory liver disease of unknown aetiology which requires lifelong immunosuppression. Most therapeutic and outcome studies of AIH have been conducted predominantly in Caucasian (European Ancestry, EA) cohorts, with the exclusion of African American (AA) patients due to inadequate sample size. It is known that AA patients have a severe phenotype of autoimmune diseases and demonstrate a poor response to conventional medical therapy. Understanding cellular and molecular pathways which determine AIH severity and progression in AA patients is likely to lead to the discovery of novel, personalised and better tolerated therapies. The aim of the study is to determine the distinct effector B cell phenotypes which contribute to disease severity and progression of AIH in AA children as compared to their EA cohorts. PBMCs were isolated from blood samples collected from patients visiting Children's Healthcare of Atlanta (CHOA) and were grouped into AA, (n = 12), EA, (n = 11) and controls (n = 12) and were processed for flow cytometry. Markers of B cell development, maturation and activation were assessed namely CD19, CD21, IgD, CD27, CD38, CD11c, CD24, CD138. AA children with AIH demonstrated an expansion of CD19 + ve, Activated Naïve (aN), (CD19+ IgD-/CD27- Double Negative (DN2) ([CD19+/IgD-/CD27++CD38++) cells. Plasmablasts were significantly higher along with Signalling Lymphocytic activation molecule F7 (SLAMF7). Unswitched memory [CD19+] IgD+CD27+ (USM) B cells were significantly contracted in AA patients with AIH. B cell phenotyping reveals a distinct profile in AA AIH patients with a major skewing towards the expansion of effector pathways which have been previously characterised in severe SLE in AA patients. These results suggest that the quantification and therapeutic target of B cell pathway could contribute substantially to the clinical approach to AIH especially in the AA population.

Quantitative measurements of M2BPGi depend on liver fibrosis and inflammation.

BACKGROUND: The relationship between liver fibrosis and inflammation and Mac-2-binding protein glycosylation isomer (M2BPGi) in patients with chronic liver disease (CLD) other than hepatitis C remains uncertain, owing to the limitations of qualitative methods. Here, we evaluated the influence of liver fibrosis and inflammation on quantitative M2BPGi (M2BPGi-Qt) in CLD, considering each etiology. METHODS: We recruited 1373 patients with CLD. To evaluate the influence of liver fibrosis and inflammation on M2BPGi-Qt levels, we assessed M2BPGi-Qt levels at each fibrosis and activity stage within different etiologies of CLD based on pathological findings. Subsequently, we evaluated if the accuracy of fibrosis staging based on M2BPGi-Qt could be improved by considering the influence of liver inflammation. RESULTS: In patients with viral hepatitis, non-alcoholic fatty liver disease, and primary biliary cholangitis, the median M2BPGi-Qt levels increased liver fibrosis progression. Median M2BPGi-Qt levels were not associated with the degree of fibrosis in patients with autoimmune hepatitis (AIH). Median M2BPGi-Qt levels increased with the progression of liver activity in all etiologies. A significant difference was found at each stage in AIH. Considering the liver inflammation, we established an algorithm, M2BPGi-Qt, to determine the alanine aminotransferase-to-platelet ratio (MAP-R) in liver cirrhosis (LC). The area under the receiver operating characteristic curve (AUC) of MAP-R was higher than that of the M2BPGi-Qt for detecting LC (AUC MAP-R = 0.759 and M2BPGi-Qt = 0.700, p < 0.001). CONCLUSIONS: The quantitative measurement system for M2BPGi depends on liver fibrosis and inflammation, regardless of etiology. Liver inflammation complicates the interpretation of M2BPGi-Qt results when assessing the fibrosis stage.

Patients with autoimmune liver disease have glucose disturbances that mechanistically differ from steatotic liver disease.

Autoimmune liver diseases are associated with an increased risk of diabetes, yet the underlying mechanisms remain unknown. In this cross-sectional study, we investigated the glucose-regulatory disturbances in patients with autoimmune hepatitis (AIH, n = 19), primary biliary cholangitis (PBC, n = 15), and primary sclerosing cholangitis (PSC, n = 6). Healthy individuals (n = 24) and patients with metabolic dysfunction-associated steatotic liver disease (MASLD, n = 18) were included as controls. Blood samples were collected during a 120-min oral glucose tolerance test. We measured the concentrations of glucose, C-peptide, insulin, glucagon, and the two incretin hormones, glucose insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). We calculated the homeostasis model assessment of insulin resistance (HOMA-IR), whole body insulin resistance (Matsuda index), insulin clearance, and insulinogenic index. All patient groups had increased fasting plasma glucose and impaired glucose responses compared with healthy controls. Beta-cell secretion was increased in AIH, PBC, and MASLD but not in PSC. Patients with AIH and MASLD had hyperglucagonemia and hepatic, as well as peripheral, insulin resistance and decreased insulin clearance, resulting in hyperinsulinemia. Patients with autoimmune liver disease had an increased GIP response, and those with AIH or PBC had an increased GLP-1 response. Our data demonstrate that the mechanism underlying glucose disturbances in patients with autoimmune liver disease differs from that underlying MASLD, including compensatory incretin responses in patients with autoimmune liver disease. Our results suggest that glucose disturbances are present at an early stage of the disease.NEW & NOTEWORTHY Patients with autoimmune liver disease but without overt diabetes display glucose disturbances early on in their disease course. We identified pathophysiological traits specific to these patients including altered incretin responses.

Elevated serum HE4 levels as a novel biomarker of disease severity and hepatic fibrosis in autoimmune hepatitis.

BACKGROUND: Human epididymis protein 4 (HE4) has been identified as a biomarker for renal fibrosis. This study aimed to evaluate the role of HE4 in the diagnosis and determination of disease severity and hepatic fibrosis in autoimmune hepatitis (AIH). METHODS: Serum HE4 levels were determined via electrochemiluminescence immunoassays in 60 healthy controls and 109 AIH patients (43 without liver cirrhosis and 66 with liver cirrhosis). Liver biopsy was performed on 56 of 109 enrolled patients. We conducted a 5-year follow-up survey of 53 enrolled patients. All continuous variables were reported as median (25th-75th percentile). RESULTS: Serum HE4 levels were significantly elevated in autoimmune hepatitis with liver cirrhosis (AIH-LC) patients compared with AIH patients and healthy controls [98.60 (74.15-139.08) vs 73.50 (59.88-82.00) vs 48.75 (43.38-52.93) pmol/L, p = 0.004]. The serum HE4 levels showed a positive correlation with the METAVIR scoring system in patients with liver biopsy (r = 0.711, p < 0.001). Serum HE4 levels were significantly elevated in Child-Pugh class C patients compared with Child-Pugh class B patients and Child-Pugh class A patients [106.50 (83.46-151.25) vs 110.00 (73.83-166.75) vs 77.03 (72.35-83.33) pmol/L, p = 0.006]. The diagnostic sensitivity and specificity of serum HE4 for evaluating liver cirrhosis were 69.7 % and 79.07 %, respectively, with a cutoff value of 82.34 pmol/L in enrolled patients. The logistic regression analysis showed that high levels of HE4 (≥82.34 pmol/L) were associated with AIH-LC (OR = 8.751, 95 % CI = 1.412-54.225, p = 0.020). The Kaplan-Meier curves demonstrated that high levels of serum HE4 (≥82.34 pmol/L) were associated with poor outcome (log-rank p = 0.037, HR = 0.372, 95 % CI = 0.146-0.946). CONCLUSIONS: Serum HE4 levels were found to be elevated in AIH-LC patients and exhibited a strong correlation with the severity of hepatic fibrosis, thus supporting their potential clinical value as a novel biomarker of disease severity and hepatic fibrosis in AIH.

Serum vitamins and homocysteine levels in autoimmune liver disease: A systematic review and meta-analysis.

OBJECTIVE: Vitamins and homocysteine (Hcy) are involved in liver metabolism and related to the pathogenesis of autoimmune liver disease (AILD), but consensus is lacking. This study aims to systematically summarize relevant evidence to clarify the association of serum vitamins and Hcy levels with AILD. METHODS: The English and Chinese literature was searched until August 29, 2023. Studies were included if they were observational studies of investigating serum vitamins and Hcy levels in patients with AILD and their healthy comparisons. Quality assessment was performed by using the Newcastle-Ottawa Scale, and a meta-analysis was conducted using ReviewManager 5.3. The protocol was registered in the international prospective register of systematic reviews (PROSPERO), with registration number CRD42023455367. RESULTS: A total of 25 case-control studies comprising 3487 patients (1673 patients and 1814 healthy controls) were included for analysis. There were 548 autoimmune hepatitis (AIH) cases, 1106 primary biliary cholangitis (PBC) cases, and 19 primary sclerosing cholangitis (PSC) cases. We found that serum A and E were decreased in both AIH and PBC/PSC; but vitamin C was reduced only in patients with PBC, not AIH. In addition, decreased content of 25(OH)D3 was found in both AIH and PBC. However, levels of 25(OH)D did not differ between the patients and controls, and were independent of disease types and the country. Only one study that met the inclusion criteria reported vitamin B6, B9, B12, and Hcy changes, and found that vitamin B6 and B9 were significantly decreased in patients with PBC, while serum vitamin B12 and Hcy levels were significantly elevated in them. One eligible study each confirmed a reduction in plasma vitamin K1 and 1,25(OH)2D3 in patients with PBC. CONCLUSION: Most vitamins are deficient in AILD, so appropriate vitamin supplementation should be necessary. Further studies with larger sample sizes are needed to validate these findings.

Previous hepatitis E virus infection is associated with increased liver stiffness in patients with autoimmune hepatitis.

INTRODUCTION: Autoimmune hepatitis (AIH) is a chronic, progressive liver disease that, in most cases, may require lifelong immunosuppression. Hepatitis E virus (HEV) is a leading cause of acute, typically self­limited hepatitis worldwide, although immunocompromised patients may develop chronic hepatitis. OBJECTIVES: We aimed to evaluate the impact of HEV seropositivity on the clinical course of AIH. PATIENTS AND METHODS: The study involved a group of 374 adult patients with AIH (68% women; median [interquartile range] age, 34 [18-83] years; 38% with liver cirrhosis). Serum HEV immunoglobulin (Ig) G and IgM antibodies were measured by enzyme­linked immunosorbent assay, liver fibrosis was assessed by liver stiffness measurement (LSM), and liver cirrhosis was confirmed with liver histology or LSM. RESULTS: Fifty­five patients (15%) with AIH were HEV IgG­positive. These patients were older (P <0.001), had higher body mass index, and higher value of LSM (both P <0.05). In a multivariable model including the levels of alanine aminotransferase and IgG, the HEV seropositive status was associated with an increased risk of advanced liver fibrosis with odds ratio of 3.69 (95% CI, 1.26-10.77; P = 0.02), as reflected by liver stiffness equal to or above 10.5 kPa. HEV IgG seropositivity was, however, not linked with the type of treatment or worse AIH outcome. Seroprevalence of HEV in the patients with AIH was lower than in the general population of Polish blood donors (43%). CONCLUSIONS: Patients with AIH and HEV IgG­positive status seem to be at risk of more advanced liver fibrosis. However, the overall seroprevalence of HEV IgG is lower in patients with AIH than in blood donors in Poland.

Clinical, biochemical and histological features related to treatment response and prognosis in autoimmune hepatitis.

INTRODUCTION AND OBJECTIVES: Autoimmune hepatitis (AIH) is a rare disease with a complex and not fully understood pathogenesis. Prognostic factors that might influence treatment response, relapse rates, and transplant-free survival are not well established. This study investigates clinical and biochemical markers associated with response to immunosuppression in patients with AIH. MATERIALS AND METHODS: This retrospective cohort study included 102 patients with AIH treated with immunosuppressants and followed at the Federal University of Minas Gerais, Brazil, from 1990 to 2018. Pretreatment data such as clinical profiles, laboratory, and histological exams were analyzed regarding biochemical response at one year, histological remission, relapse, and death/transplantation rates. RESULTS: Cirrhosis was present in 59 % of cases at diagnosis. One-year biochemical remission was observed in 55.7 % of the patients and was found to be a protective factor for liver transplant. Overall survival was 89 %. Patients with ascites at disease onset showed a higher aspartate aminotransferase (AST)/ alanine aminotransferase (ALT) ratio and elevated Model of end-stage liver disease (MELD) score. The presence of ascites was significantly associated with a 20-fold increase in mortality rate. CONCLUSIONS: AIH has a severe clinical phenotype in Brazilians, with high rates of cirrhosis and low remission rates. Early diagnosis and treatment are essential for achieving remission and reducing complications. The presence of ascites is significantly associated with mortality, emphasizing the importance of monitoring and prompt intervention. This study also stresses the need for further research on AIH in Latin America.

Characteristics of peripheral blood mononuclear cells and potential related molecular mechanisms in patients with autoimmune hepatitis: a single-cell RNA sequencing analysis.

Autoimmune hepatitis (AIH) is an immune disorder characterized by hypergammaglobulinemia, autoantibodies, and chronic active hepatitis on liver histology. However, immune cell population characteristics in AIH patients remain poorly understood. This study was designed to analyze peripheral blood mononuclear cell (PBMC) characteristics in AIH through single-cell RNA sequencing (scRNA-seq) and explore potential AIH-related molecular mechanisms. We generated 3690 and 3511 single-cell transcriptomes of PBMCs pooled from 4 healthy controls (HCs) and 4 AIH patients, respectively, by scRNA-seq. These pooled PBMC transcriptomes were used for cell cluster identification and differentially expressed gene (DEG) identification. GO functional enrichment analysis was performed on the DEGs to determine the most active AIH immune cell biological functions. Although the PCA-based uniform manifold approximation and projection (UMAP) algorithm was used to cluster cells with similar expression patterns in the two samples, 87 up- and 12 downregulated DEGs were retained in monocytes and 101 up- and 15 downregulated DEGs were retained in NK cells from AIH PBMCs. Moreover, enriched GO terms in the PBMC-derived monocyte and NK cell clusters were related mainly to antigen processing and presentation, IFN-γ-mediated signaling, and neutrophil degranulation and activation. These potential molecular mechanisms may be important targets for AIH treatment.

Development and validation of a noninvasive prediction model for significant hepatic liver fibrosis in Chinese patients with autoimmune hepatitis.

INTRODUCTION AND OBJECTIVES: Autoimmune hepatitis (AIH) is a prevalent noninfectious liver disease. However, there is currently a lack of noninvasive tests appropriate for evaluating liver fibrosis in AIH patients. The objective of this study was to develop and validate a predictive model for noninvasive assessment of significant liver fibrosis (S ≥ 2) in patients to provide a reliable method for evaluating liver fibrosis in individuals with AIH. MATERIALS AND METHODS: The clinical data of 374 AIH patients were analyzed. A prediction model was established through logistic regression in the training set, and bootstrap method was used to validate the models internally. In addition, the clinical data of 109 AIH patients were collected for external verification of the model.The model was expressed as a nomogram, and area under the curve (AUC) of the receiver operating characteristic (ROC), calibration curve, and decision curve analysis were used to evaluate the accuracy of the prediction model. RESULTS: Logistic regression analysis revealed that age, platelet count (PLT), and the A/G ratio were identified as independent risk factors for liver fibrosis in AIH patients (P < 0.05). The diagnostic model that was composed of age, PLT and A/G was superior to APRI and FIB-4 in both the internal validation (0.872, 95%CI: 0.819-0.924) and external validation (0.829, 95%CI: 0.753-0.904). CONCLUSIONS: Our predictive model can predict significant liver fibrosis in AIH patients more accurately, simply, and noninvasively.

[Utility of the detection of autoantibodies in autoinmune liver diseases using immunoblot]. / Evaluación del panel de enfermedades hepáticas autoinmunes (INMUNOBLOT) en el diagnóstico de enfermedades hepáticas.

INTRODUCTION: For the diagnosis of liver diseases, clinical criteria, biochemical, immunological and histological parameters are included. The autoimmune panel is an immunoblot that contemplates the detection of antibodies against 9 different hepatic antigens, which could guide the diagnosis of these pathologies. OBJECTIVE: To describe the usefulness of the autoimmune panel in the diagnosis of liver diseases. METHODS: Observational, descriptive study. All autoimmune panels performed between January 2020 and August 2021 (n = 279) were reviewed, and the ones with positive result selected (n = 101). Clinical records were reviewed, including: clinical, biochemical, immunological and histological characteristics. Diagnosis was determined by clinical suspicion (clinical, biochemical and immunological parameters), only through autoimmune panel, and according to liver biopsy in available cases. RESULTS: 45 patients with complete clinical history were included in the analysis; 82% women, median age 58 years (16-79). Clinical suspicions included autoimmune hepatitis (AIH) in 12 patients (27%), primary biliary cholangitis (PBC) in 10 patients (22%), overlap syndrome (AIH/PBC) in 17 (38%), and others in 6 (13%). The diagnosis of PBC was confirmed by autoimmune panel in 9/10 and 11/17 patients with clinical suspicion of PBC and HAI/PBC, respectively. Of the 27 patients with initial clinical suspicion of PBC, 14 had negative AMA and AMA-M2 (6 had Sp100 and 5 gp210 as the only markers and 3 had positive Sp100 and PML). In 10/14 patients, the diagnosis was confirmed by panel and/or compatible liver biopsy. CONCLUSION: The autoimmune panel turns out to be a useful diagnostic tool for liver diseases, especially PBC in isolation or in overlap syndrome.

Increased serum anti-CYP2E1 IgG autoantibody levels may be involved in the pathogenesis of occupational trichloroethylene hypersensitivity syndrome: a case-control study.

Occupational exposure to trichloroethylene (TCE) causes a systemic skin disorder with hepatitis known as TCE hypersensitivity syndrome (TCE-HS). Human Leukocyte Antigen (HLA)-B*13:01 is its susceptibility factor; however, the immunological pathogenesis of TCE-HS remains unknown. We herein examined the hypothesis that autoantibodies to CYP2E1 are primarily involved in TCE-HS. A case-control study of 80 TCE-HS patients, 186 TCE-tolerant controls (TCE-TC), and 71 TCE-nonexposed controls (TCE-nonEC) was conducted to measure their serum anti-CYP2E1 antibody (IgG) levels. The effects of TCE exposure indices, such as 8-h time-weighted-average (TWA) airborne concentrations, urinary metabolite concentrations, and TCE usage duration; sex; smoking and drinking habits; and alanine aminotransferase (ALT) levels on the antibody levels were also analyzed in the two control groups. There were significant differences in anti-CYP2E1 antibody levels among the three groups: TCE-TC > TCE-HS patients > TCE-nonEC. Antibody levels were not different between HLA-B*13:01 carriers and noncarriers in TCE-HS patients and TCE-TC. The serum CYP2E1 measurement suggested increased immunocomplex levels only in patients with TCE-HS. Multiple regression analysis for the two control groups showed that the antibody levels were significantly higher by the TCE exposure. Women had higher antibody levels than men; however, smoking, drinking, and ALT levels did not affect the anti-CYP2E1 antibody levels. Anti-CYP2E1 antibodies were elevated at concentrations lower than the TWA concentration of 2.5 ppm for TCE exposure. Since HLA-B*13:01 polymorphism was not involved in the autoantibody levels, the possible mechanism underlying the pathogenesis of TCE-HS is that TCE exposure induces anti-CYP2E1 autoantibody production, and HLA-B*13:01 is involved in the development of TCE-HS.

E. coli and the etiology of human PBC: Antimitochondrial antibodies and spreading determinants.

BACKGROUND AND AIMS: The increased frequency of urinary tract infections in patients with primary biliary cholangitis (PBC) and the cross-reactivity between the lipoyl domains (LD) of human pyruvate dehydrogenase complex (hPDC-E2) and Escherichia coli PDC-E2 (ePDC-E2) have long suggested a role of E. coli in causality of PBC. This issue, however, has remained speculative. We hypothesized that by generating specific constructs of human and E. coli PDC-E2, we would be able to assess the specificity of autoantibody responses and define whether exposure to E. coli in susceptible hosts is the basis for the antimitochondrial antibody (AMA) response. APPROACH AND RESULTS: Importantly, the reactivity of hPDC-E2 LD (hPDC-E2LD) affinity-purified antibodies against hPDC-E2LD could only be removed by prior absorption with hPDC-E2LD and not ePDC-E2, suggesting the presence of unique human PDC-E2 epitopes distinct from E. coli PDC-E2. To identify the autoepitope(s) present in hPDC-E2LD, a more detailed study using a variety of PDC-E2 constructs was tested, including the effect of lipoic acid (LA) on ePDC-E2 conformation and AMA recognition. Individual recombinant ePDCE2 LD domains LD1, LD2 and LD3 did not react with either AMA or antibodies to LA (anti-LA), but in contrast, anti-LA was readily reactive against purified recombinant LD1, LD2, and LD3 expressed in tandem (LP); such reactivity increased when LP was precultured with LA. Moreover, when the three LD (LD1, LD2, LD3) domains were expressed in tandem in pET28a or when LD1 was expressed in another plasmid pGEX, they were lipoylated and reactive to PBC sera. CONCLUSIONS: In conclusion, our data are consistent with an exposure to E. coli that elicits specific antibody to ePDC-E2 resulting in determinant spreading and the classic autoantibody to hPDC-E2LD. We argue this is the first step to development of human PBC.

Quantification of polyreactive immunoglobulin G facilitates the diagnosis of autoimmune hepatitis.

BACKGROUND AND AIMS: Detection of autoantibodies is a mainstay of diagnosing autoimmune hepatitis (AIH). However, conventional autoantibodies for the workup of AIH lack either sensitivity or specificity, leading to substantial diagnostic uncertainty. We aimed to identify more accurate serological markers of AIH with a protein macroarray. APPROACH AND RESULTS: During the search for more-precise autoantibodies to distinguish AIH from non-AIH liver diseases (non-AIH-LD), IgG antibodies with binding capacities to many human and foreign proteins were identified with a protein macroarray and confirmed with solid-phase ELISAs in AIH patients. Subsequently, polyreactive IgG (pIgG) was exemplarily quantified by reactivity against human huntingtin-interacting protein 1-related protein in bovine serum albumin blocked ELISA (HIP1R/BSA). The diagnostic fidelity of HIP1R/BSA binding pIgG to diagnose AIH was assessed in a retrospective training, a retrospective multicenter validation, and a prospective validation cohort in cryoconserved samples from 1,568 adults from 10 centers from eight countries. Reactivity against HIP1R/BSA had a 25% and 14% higher specificity to diagnose AIH than conventional antinuclear and antismooth muscle antibodies, a significantly higher sensitivity than liver kidney microsomal antibodies and antisoluble liver antigen/liver pancreas antigen, and a 12%-20% higher accuracy than conventional autoantibodies. Importantly, HIP1R/BSA reactivity was present in up to 88% of patients with seronegative AIH and in up to 71% of AIH patients with normal IgG levels. Under therapy, pIgG returns to background levels of non-AIH-LD. CONCLUSIONS: pIgG could be used as a promising marker to improve the diagnostic workup of liver diseases with a higher specificity for AIH compared to conventional autoantibodies and a utility in autoantibody-negative AIH. Likewise, pIgG could be a major source of assay interference in untreated AIH.

Lymphocyte Profile and Immune Checkpoint Expression in Drug-Induced Liver Injury: An Immunophenotyping Study.

The identification of specific HLA risk alleles in drug-induced liver injury (DILI) points toward an important role of the adaptive immune system in DILI development. In this study, we aimed to corroborate the role of an adaptive immune response in DILI through immunophenotyping of leukocyte populations and immune checkpoint expressions. Blood samples were collected from adjudicated DILI (n = 12), acute viral hepatitis (VH; n = 13), acute autoimmune hepatitis (AIH; n = 9), and acute liver injury of unknown etiology (n = 15) at day 1 (recognition), day 7, and day >30. Blood samples from patients with nonalcoholic fatty liver disease (NAFLD; n = 20) and healthy liver controls (HLCs; n = 54) were extracted at one time point. Leukocyte populations and immune checkpoint expressions were determined based on cell surface receptors, except for CTLA-4 that was determined intracellularly, using flow cytometry. At recognition, DILI demonstrated significantly higher levels of activated helper T-cell (P < 0.0001), activated cytotoxic T-cells (P = 0.0003), Th1 (P = 0.0358), intracellular CTLA-4 level in helper T-cells (P = 0.0192), and PD-L1 presenting monocytes (P = 0.0452) than HLC. These levels approached those of HLC over time. No significant differences were found between DILI and VH. However, DILI presented higher level of activated helper T-cells and CTLA-4 than NAFLD and lower PD-L1 level than AIH. Our findings suggest that an adaptive immune response is involved in DILI in which activated CD4+ and CD8+ play an important role. Increased expression of negative immune checkpoints is likely the effect of peripheral tolerance regulation.

Diagnosis and Therapeutic Management of Liver Fibrosis by MicroRNA.

Remarkable progress has been made in the treatment and control of hepatitis B and C viral infections. However, fundamental treatments for diseases in which liver fibrosis is a key factor, such as cirrhosis, alcoholic/nonalcoholic steatohepatitis, autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, are still under development and remain an unmet medical need. To solve this problem, it is essential to elucidate the pathogenesis of liver fibrosis in detail from a molecular and cellular perspective and to develop targeted therapeutic agents based on this information. Recently, microRNAs (miRNAs), functional RNAs of 22 nucleotides, have been shown to be involved in the pathogenesis of liver fibrosis. In addition, extracellular vesicles called "exosomes" have been attracting attention, and research is being conducted to establish noninvasive and extremely sensitive biomarkers using miRNAs in exosomes. In this review, we summarize miRNAs directly involved in liver fibrosis, miRNAs associated with diseases leading to liver fibrosis, and miRNAs related to complications of cirrhosis. We will also discuss the efficacy of each miRNA as a biomarker of liver fibrosis and pathology, and its potential application as a therapeutic agent.

Prevalence and Clinical Significance of Autoantibodies in Children with Overweight and Obesity with Nonalcoholic Fatty Liver Disease.

OBJECTIVES: To evaluate the prevalence and clinical significance of autoantibodies in children with overweight and obesity with nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) compared with those with autoimmune liver disease (ALD). STUDY DESIGN: This was a retrospective, cross-sectional study of children with a biopsy-proven diagnosis of NAFL, NASH, autoimmune hepatitis (AIH), or primary sclerosing cholangitis (PSC) and a body mass index (BMI) >85th percentile treated between 2007 and 2016. RESULTS: A total of 181 patients were identified, including 31 (17%) with NAFL, 121 (67%) with NASH, 12 (6.6%) with ALD (AIH, PSC, or overlap), and 17 (9.4%) with combined ALD and NAFLD. Antinuclear antibody (ANA), anti-actin antibody, and anti-liver kidney microsomal (LKM) antibody were positive in 16.1%, 13.8%, and 0%, respectively, of the patients with NAFL and in 32.8%, 15.5%, and 0%, respectively, of those with NASH. Total immunoglobulin G (IgG) was elevated in 27.3% of the patients with NAFL and in 47.7% of those with NASH, but in 100% of those with ALD. The positive predictive value of LKM was 100% for ALD but only 29% for ANA and 46% for anti-actin antibody. CONCLUSIONS: False-positive rates of autoantibodies were higher in pediatric patients with overweight and obesity with NAFLD compared with the general adult population. Positive LKM had the highest specificity and positive predictive value, and elevated IgG level had the highest sensitivity for ALD. The presence of autoantibodies does not signal more severe NAFLD in children. BMI >98th percentile seems to be an important breakpoint above which ALD is less likely.

Quantitative multiparametric MRI as a non-invasive stratification tool in children and adolescents with autoimmune liver disease.

Autoimmune hepatitis (AIH) and autoimmune sclerosing cholangitis (ASC) are two very closely related autoimmune liver diseases with overlapping clinical features and similar management strategies. The purpose of this study was to assess the utility of quantitative imaging markers to distinguish ASC from AIH in paediatrics. 66 participants (N = 52 AIH, N = 14 ASC) aged 14.4 ± 3.3 years scheduled to undergo routine biopsy and baseline serum liver biochemistry testing were invited to undergo MRI (non-contrast abdominal MRI and 3D fast spin-echo MRCP). Multiparametric MRI was used to measure fibro-inflammation with corrected T1 (cT1), while the biliary tree was modelled   using quantitative MRCP (MRCP +). Mann-Whitney U tests were performed to compare liver function tests with imaging markers between patient groups (ASC vs AIH). Receiver operating characteristic curves and stepwise logistic regressions were used to identify the best combination of markers to discriminate between ASC and AIH. Correlations between liver function tests and imaging markers were performed using Spearman's rank correlation. cT1 was significantly correlated with liver function tests (range 0.33 ≤ R ≤ 56, p < 0.05), as well as with fibrosis, lobular and portal inflammation (range 0.31 ≤ R ≤ 42, p < 0.05). 19 MRCP + metrics correlated significantly with liver function tests (range 0.29 ≤ R ≤ 0.43, p < 0.05). GGT and MRCP + metrics were significantly higher in ASC compared to those with AIH. The best multivariable model for distinguishing ASC from AIH included total number of ducts and the sum of relative severity of both strictures and dilatations AUC: 0.91 (95% CI 0.78-1). Quantitative MRCP metrics are a good discriminator of ASC from AIH.