Steatohepatitic hepatocellular Carcinoma:A new approach to classifying morphological subtypes of hepatocellular carcinoma.

Histological subtyping of hepatocellular carcinoma (HCC) is challenging in the presence of histological heterogeneity, where distinctly different morphological patterns are present within the same tumor. Current approaches rely on percent cut-offs. We hypothesized that morphologic intratumor heterogeneity is a non-random biological feature and that incorporating recurrent patterns would improve histological subtyping of HCC. Resected HCC were studied and the overall frequency of morphologic intratumor heterogeneity was 45% in 242 specimens. Steatohepatitic HCC (SH-HCC) had the highest frequency of morphologic intratumor heterogeneity (91%); this was confirmed in additional cohorts of SH-HCC from different medical centers (overall frequency of 78% in SH-HCC). Morphologic intratumor heterogeneity in SH-HCC showed distinct and recurrent patterns that could be classified as early, intermediate, and advanced. Incorporating these patterns into the definition of SH-HCC allowed successful resolution of several persistent challenges: the problem of the best cut-off for subtyping SH-HCC, the problem of the relationship between SH-HCC and scirrhous HCC, and the classification for HCC with abundant microvesicular steatosis. This approach also clarified the relationship between SH-HCC and CTNNB1 mutations, showing that CTNNB1 mutations occur late in a subset of SH-HCC. In summary, there is a high frequency of morphologic intratumor heterogeneity in HCC. Incorporating this finding into histological subtyping resolved several persistent problems with the SH-HCC subtype.

Spatial Deconvolution of Cell Types and Cell States at Scale Utilizing TACIT.

Identifying cell types and states remains a time-consuming and error-prone challenge for spatial biology. While deep learning is increasingly used, it is difficult to generalize due to variability at the level of cells, neighborhoods, and niches in health and disease. To address this, we developed TACIT, an unsupervised algorithm for cell annotation using predefined signatures that operates without training data, using unbiased thresholding to distinguish positive cells from background, focusing on relevant markers to identify ambiguous cells in multiomic assays. Using five datasets (5,000,000-cells; 51-cell types) from three niches (brain, intestine, gland), TACIT outperformed existing unsupervised methods in accuracy and scalability. Integration of TACIT-identified cell with a novel Shiny app revealed new phenotypes in two inflammatory gland diseases. Finally, using combined spatial transcriptomics and proteomics, we discover under- and overrepresented immune cell types and states in regions of interest, suggesting multimodality is essential for translating spatial biology to clinical applications.

Increases and decreases in liver stiffness measurement are independently associated with the risk of liver-related events in NAFLD.

BACKGROUND & AIMS: The clinical significance of change in liver stiffness measurement (LSM) by vibration-controlled transient elastography (VCTE) in patients with non-alcoholic fatty liver disease (NAFLD) is not well-understood. We prospectively defined rates of progression to and regression from LSM-defined compensated advanced chronic liver disease (cACLD) and their associations with liver-related events (LREs). METHODS: Participants in the NASH Clinical Research Network-led NAFLD Database 2 and 3 studies were included. Progression to cACLD was defined as reaching LSM ≥10 kPa in participants with LSM <10 kPa on initial VCTE; regression from cACLD was defined as reaching LSM <10 kPa in participants with baseline LSM ≥10 kPa. LREs were defined as liver-related death, liver transplant, hepatocellular carcinoma, MELD >15, development of varices, or hepatic decompensation. Univariate and multivariable interval-censored Cox regression analyses were used to compare the cumulative LRE probability by LSM progression and regression status. RESULTS: In 1,403 participants, 89 LREs developed over a mean follow-up of 4.4 years, with an annual incidence rate for LREs of 1.5 (95% CI 1.2-1.8). In participants at risk, progression to LSM ≥10 or ≥15 kPa occurred in 29% and 17%, respectively, whereas regression to LSM <10 or <15 kPa occurred in 44% and 49%, respectively. Progressors to cACLD (≥10 kPa) experienced a higher cumulative LRE rate vs. non-progressors (16% vs. 4%, adjusted hazard ratio 4.0; 95% (1.8-8.9); p <0.01). Regressors from cACLD (to LSM <10 kPa) experienced a lower LRE rate than non-regressors (7% vs. 32%, adjusted hazard ratio 0.25; 95% CI 0.10-0.61; p <0.01). CONCLUSIONS: Change in LSM over time is independently and bi-directionally associated with risk of LRE and is a non-invasive surrogate for clinical outcomes in patients with NAFLD. IMPACT AND IMPLICATIONS: The prognostic value of change in LSM in patients with NAFLD is not well understood. In this large prospective study of patients with NAFLD and serial vibration-controlled transient elastography exams, baseline and dynamic changes in LSM were associated with the risk of developing liver-related events. LSM is a useful non-invasive surrogate of clinical outcomes in patients with NAFLD.

Persistent GDNF Expression 45 Months after Putaminal Infusion of AAV2-GDNF in a Patient with Parkinson's Disease.

OBJECTIVE: Gene therapy by convection-enhanced delivery of type 2 adeno-associated virus-glial cell derived neurotrophic factor (AAV2-GDNF) to the bilateral putamina seeks to increase GDNF gene expression and treat Parkinson's disease (PD). METHODS: A 63-year-old man with advanced PD received AAV2-GDNF in a clinical trial. He died from pneumonia after anterior cervical discectomy and fusion 45 months later. An autopsy included brain examination for GDNF transgene expression. Putaminal catecholamine concentrations were compared to in vivo 18F-Fluorodopa (18F-FDOPA) positron emission tomography (PET) scanning results before and 18 months after AAV2-GDNF infusion. RESULTS: Parkinsonian progression stabilized clinically. Postmortem neuropathology confirmed PD. Bilateral putaminal regions previously infused with AAV2-GDNF expressed the GDNF gene. Total putaminal dopamine was 1% of control, confirming the striatal dopaminergic deficiency suggested by baseline 18F-DOPA-PET scanning. Putaminal regions responded as expected to AAV2-GDNF. CONCLUSION: After AAV2-GDNF infusion, infused putaminal regions showed increased GDNF gene expression, tyrosine hydroxylase immunoreactive sprouting, catechol levels, and 18F-FDOPA-PET signal, suggesting the regenerative potential of AAV2-GDNF in PD. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Effects of Metreleptin in Patients with Generalized Lipodystrophy Before vs After the Onset of Severe Metabolic Disease.

CONTEXT: Leptin replacement therapy with metreleptin improves metabolic abnormalities in patients with generalized lipodystrophy (GLD). OBJECTIVE: Determine how timing of metreleptin initiation in the clinical course of GLD affects long-term metabolic health. METHODS: Retrospective analysis of patients ≥ 6 months old with congenital (n=47) or acquired (n=16) GLD treated with metreleptin at the National Institutes of Health since 2001. Least squares means (LSM) for HbA1c, insulin area under the curve (AUC) from oral glucose tolerance tests, triglycerides, urine protein excretion, platelets, transaminases, and aspartate aminotransferase (AST) to Platelet Ratio Index (APRI) for early and late treatment groups, defined by baseline metabolic health, were analyzed during median 72 (24, 108) months follow-up. RESULTS: Compared to late groups, early groups based on metabolic status had higher mean±SEM insulin AUC (20831±1 vs 11948±1), lower HbA1c (5.3±0.3 vs 6.8±0.3%), triglycerides (101±1 vs 193±1 mg/dL), urine protein excretion (85±1.5 vs 404±1.4 mg/24 hr), ALT (30±1 vs 53±1 U/L), AST (23±1 vs 40±1 U/L), and APRI (0.22±1.3 vs 0.78±1.3), and higher platelets (257±24 vs 152±28 K/µL) during follow-up (P<0.05). Compared to patients ≥6 years old at baseline, patients <6 years had lower HbA1c (4.5±0.5 vs 6.4±0.2%) and higher AST (40±1vs 23±1 U/L) during follow (P<0.05). CONCLUSION: Patients with GLD who initiated metreleptin before the onset of severe metabolic complications had better long-term control of diabetes, proteinuria, and hypertriglyceridemia. Early treatment may also result is less severe progression of liver fibrosis, but further histological studies are needed to determine the effects of metreleptin therapy on liver disease.

The Role of Interferon-γ in Autoimmune Polyendocrine Syndrome Type 1.

BACKGROUND: Autoimmune polyendocrine syndrome type 1 (APS-1) is a life-threatening, autosomal recessive syndrome caused by autoimmune regulator (AIRE) deficiency. In APS-1, self-reactive T cells escape thymic negative selection, infiltrate organs, and drive autoimmune injury. The effector mechanisms governing T-cell-mediated damage in APS-1 remain poorly understood. METHODS: We examined whether APS-1 could be classified as a disease mediated by interferon-γ. We first assessed patients with APS-1 who were participating in a prospective natural history study and evaluated mRNA and protein expression in blood and tissues. We then examined the pathogenic role of interferon-γ using Aire-/-Ifng-/- mice and Aire-/- mice treated with the Janus kinase (JAK) inhibitor ruxolitinib. On the basis of our findings, we used ruxolitinib to treat five patients with APS-1 and assessed clinical, immunologic, histologic, transcriptional, and autoantibody responses. RESULTS: Patients with APS-1 had enhanced interferon-γ responses in blood and in all examined autoimmunity-affected tissues. Aire-/- mice had selectively increased interferon-γ production by T cells and enhanced interferon-γ, phosphorylated signal transducer and activator of transcription 1 (pSTAT1), and CXCL9 signals in multiple organs. Ifng ablation or ruxolitinib-induced JAK-STAT blockade in Aire-/- mice normalized interferon-γ responses and averted T-cell infiltration and damage in organs. Ruxolitinib treatment of five patients with APS-1 led to decreased levels of T-cell-derived interferon-γ, normalized interferon-γ and CXCL9 levels, and remission of alopecia, oral candidiasis, nail dystrophy, gastritis, enteritis, arthritis, Sjögren's-like syndrome, urticaria, and thyroiditis. No serious adverse effects from ruxolitinib were identified in these patients. CONCLUSIONS: Our findings indicate that APS-1, which is caused by AIRE deficiency, is characterized by excessive, multiorgan interferon-γ-mediated responses. JAK inhibition with ruxolitinib in five patients showed promising results. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

Severe acute liver disease in adults: Contemporary role of histopathology.

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

Prospective evaluation of patients with non-cirrhotic portal hypertension: A single centre study.

BACKGROUND: Non-cirrhotic portal hypertension (NCPH) is a spectrum of liver diseases, including porto-sinusoidal vascular disorder, with portal hypertension (PH) in the absence of cirrhosis. The natural history and diagnostic approach to NCPH are not well understood. AIM: We aimed to evaluate disease progression and outcomes in NCPH. METHODS: Patients with or at risk for NCPH were enrolled in a single centre prospective study; two groups were formed based on the presence of specific features of PH, such as varices, collaterals, portal hypertensive gastropathy or portal hypertensive bleeding. All participants underwent a baseline liver biopsy. Liver stiffness measurement (LSM), and imaging were repeated every 6-12 months. RESULTS: Fifteen patients without specific features of PH (Group I), and 35 patients with specific features (Group II) were enrolled. The median follow-up time was 50 months. Group II had higher hepatic venous pressure gradients, non-invasive measures of PH and a lower platelet count (PLT) when compared to Group I. Rates of survival and decompensation were similar in both groups. Patients with PLT ≤100 K/mcL had lower survival compared to those with PLT >100 K/mcL. Patients with LSM ≥10 kPa had lower survival and survival without decompensation when compared to patients with LSM <10 kPa. CONCLUSIONS: Patients irrespective of specific features of PH had similar survival or survival without decompensation. Patients without specific features are at risk for disease progression and should be monitored closely. Thrombocytopenia and increased LSM are associated with severe forms of liver disease, which are strongly associated with outcomes.

Porto-Sinusoidal Vascular Disease in Congenital Erythropoietic Porphyria Needing Liver Transplantation.

Porphyria caused by inherited disorders in heme biosynthesis can lead to accumulation of porphyrins in various organs. Liver involvement due to porphyria mostly results in cholestasis leading to liver cirrhosis or hepatocellular carcinoma. Congenital erythropoietic porphyria (CEP), a rare porphyria due to deficiency of uroporphyrinogen III synthase, mostly results in cutaneous manifestations. There are reports of liver involvement including varying degree of fibrosis in patients with CEP. We report a unique case of a patient with CEP who developed porto-sinusoidal vascular disease with complications of portal hypertension that necessitated liver transplantation.

Inhibition of JAK-STAT pathway corrects salivary gland inflammation and interferon driven immune activation in Sjögren's disease.

OBJECTIVES: Inflammatory cytokines that signal through the Janus kinases-signal transducer and activator of transcription (JAK-STAT) pathway, especially interferons (IFNs), are implicated in Sjögren's disease (SjD). Although inhibition of JAKs is effective in other autoimmune diseases, a systematic investigation of IFN-JAK-STAT signalling and the effect of JAK inhibitor (JAKi) therapy in SjD-affected human tissues has not been fully investigated. METHODS: Human minor salivary glands (MSGs) and peripheral blood mononuclear cells (PBMCs) were investigated using bulk or single-cell (sc) RNA sequencing (RNAseq), immunofluorescence (IF) microscopy and flow cytometry. Ex vivo culture assays on PBMCs and primary salivary gland epithelial cell (pSGEC) lines were performed to model changes in target tissues before and after JAKi. RESULTS: RNAseq and IF showed activated JAK-STAT pathway in SjD MSGs. Elevated IFN-stimulated gene (ISGs) expression associated with clinical variables (eg, focus scores, anti-SSA positivity). scRNAseq of MSGs exhibited cell type-specific upregulation of JAK-STAT and ISGs; PBMCs showed similar trends, including markedly upregulated ISGs in monocytes. Ex vivo studies showed elevated basal pSTAT levels in SjD MSGs and PBMCs that were corrected with JAKi. SjD-derived pSGECs exhibited higher basal ISG expressions and exaggerated responses to IFN-ß, which were normalised by JAKi without cytotoxicity. CONCLUSIONS: SjD patients' tissues exhibit increased expression of ISGs and activation of the JAK-STAT pathway in a cell type-dependent manner. JAKi normalises this aberrant signalling at the tissue level and in PBMCs, suggesting a putative viable therapy for SjD, targeting both glandular and extraglandular symptoms. Predicated on these data, a phase Ib/IIa randomised controlled trial to treat SjD with tofacitinib was initiated.

Drug-induced liver injury (DILI) ascribed to non-steroidal anti-inflammatory drugs (NSAIDs) in the USA-Update with genetic correlations.

OBJECTIVE: To describe patients with NSAID-DILI, including genetic factors associated with idiosyncratic DILI. METHODS: In DILIN, subjects with presumed DILI are enrolled and followed for at least 6 months. Causality is adjudicated by a Delphic approach. HLA sequencing of multiethnic NSAID-DILI patients and HLA allele imputation of matching population controls were performed following overall, class and drug-based association analysis. Significant results were tested in a non-Hispanic White (NHW) case-control replication cohort. RESULTS: Between September 2004 and March 2022, causality was adjudicated in 2498, and 55 (41 [75%] women) were assessed as likely due to NSAIDs. Median age at onset was 55 y (range 22-83 y). Diclofenac was the causative drug in 29, celecoxib in 7, ibuprofen in 5, etodolac and meloxicam each in 4. Except for meloxicam and oxaprozin (n = 2), the liver injury was hepatocellular with median R 15-25. HLA-DRB1*04:03 and HLA-B*35:03 were significantly more frequent in NSAID-DILI patients than in non-NSAID DILI controls. Interestingly, 85% of the HLA-DRB1*04:03 carriers developed DILI due to the use of acetic acid derivative NSAIDs, supporting the hypothesis that HLA-DRB1*04:03 could be a drug and/or class risk factor. HLA-B*35:03 but not HLA-DRB1*04:03 association was confirmed in the independent NHW replication cohort, which was largely driven by diclofenac. CONCLUSIONS: Despite prevalent use, NSAID-DILI is infrequent in the United States. Diclofenac is the most commonly implicated, and adherence to warnings of risk and close observation are recommended. The increased frequency of HLA-B*35:03 and DRB1*04:03, driven by diclofenac, suggests the importance of immune-mediated responses.

Granulomatous liver diseases.

A granuloma is a discrete collection of activated macrophages and other inflammatory cells. Hepatic granulomas can be a manifestation of localized liver disease or be a part of a systemic process, usually infectious or autoimmune. A liver biopsy is required for the detection and evaluation of granulomatous liver diseases. The prevalence of granulomas on liver biopsy varies from 1% to 15%. They may be an incidental finding in an asymptomatic individual, or they may represent granulomatous hepatitis with potential to progress to liver failure, or in chronic disease, to cirrhosis. This review focuses on pathogenesis, histological features of granulomatous liver diseases, and most common etiologies, knowledge that is essential for timely diagnosis and intervention.

ERAP-1 and ERAP-2 Variants in Liver Injury After COVID-19 mRNA Vaccination: A US Multicenter Study.

INTRODUCTION: The aim of this study is to describe the presenting features, genetic factors, and outcomes of 23 adults who developed liver injury after coronavirus disease 2019 (COVID-19) mRNA vaccination. METHODS: Patients with suspected COVID-19 vaccine hepatitis were enrolled into the Drug-Induced Liver Injury Network. Causality was assessed using the Drug-Induced Liver Injury Network expert opinion score. High-resolution HLA sequencing was undertaken using Illumina platform. RESULTS: Amongst the 16 high causality cases, median time to onset was 16 days, median age was 63 years, and 75% were female. The injury was hepatocellular in 75% with a median alanine aminotransferase of 497 U/L, and 37% had jaundice. An antinuclear antibody and smooth muscle antibody were detectable in 27% and 36%, but only 12% had an elevated immunoglobulin G level. During follow-up, 37% received a short course of corticosteroids, and 88% fully recovered by 6 months with no deaths observed. HLA alleles associated with autoimmune hepatitis were not overrepresented compared with controls, but an ERAP-2 variant (rs1263907) and the ERAP-1 Hap6 haplotype were significantly overrepresented in the high causality cases vs controls ( P = 0.026 and 5 × 10 -5 , respectively). DISCUSSION: Acute liver injury may arise within 8 weeks of COVID-19 mRNA vaccination that is generally mild and self-limited in most patients. The absence of an association with the AIH HLA alleles combined with the significant ERAP-2 and ERAP-1 Hap6 haplotype associations implicates a unique but very rare host immune response to vaccine-derived antigens in the pathogenesis of COVID-19 vaccine hepatotoxicity.

Chronic Liver Disease in Patients with Prolidase Deficiency: A Case Series.

Introduction: Prolidase deficiency is a rare autosomal recessive disorder caused by variants in the PEPD gene. Patients usually have multi-organ involvement and a wide range of clinical features including recurrent skin ulcers, dysmorphic facial features, recurrent infections, intellectual disability, and splenomegaly. Studies have shown that patients with prolidase deficiency may have hepatic manifestations including hepatomegaly and abnormal liver enzymes. However, there is no detailed description of liver disease in this patient population. Case Presentation: Here, we present 3 patients with prolidase deficiency with varying extents of hepatic involvement. Conclusion: Prolidase deficiency patients with liver disease should be followed up long term to understand more about the pathophysiology and the impact of liver disease on long-term outcomes.

Combined immune checkpoint inhibition with durvalumab and tremelimumab with and without radiofrequency ablation in patients with advanced biliary tract carcinoma.

BACKGROUND: Current standard of care for advanced biliary tract cancer (BTC) is gemcitabine, cisplatin plus anti-PD1/PD-L1, but response rates are modest. The purpose of this study was to explore the efficacy and safety of durvalumab (anti-PD-L1) and tremelimumab (anti-CTLA-4), with and without an interventional radiology (IR) procedure in advanced BTC. METHODS: Eligible patients with advanced BTC who had received or refused at least one prior line of systemic therapy were treated with tremelimumab and durvalumab for four combined doses followed by monthly durvalumab alone with and without an IR procedure until the progression of disease or unacceptable toxicity. Objective response was assessed through CT or MRI by Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) every 8 weeks. Adverse events (AEs) were recorded and managed. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: Twenty-three patients with advanced BTC were enrolled; 17 patients were assigned to treatment with durvalumab and tremelimumab (Durva/Treme); and 6 patients were treated with the combination of durvalumab, tremelimumab plus IR procedure (Durva/Treme + IR). The best clinical responses in the Durva/Treme arm were partial response (n = 1), stable disease (n = 5), progressive disease (n = 5), and in the Durva/Treme + IR arm: partial response (n = 0), stable disease (n = 3), progressive disease (n = 3). The median PFS was 2.2 months (95% CI: 1.3-3.1 months) in the Durva/Treme arm and 2.9 months (95% CI: 1.9-4.7 months) in the Durva/Treme + IR arm (p = 0.27). The median OS was 5.1 months (95% CI: 2.5-6.9 months) in the Durva/Treme arm and 5.8 months (95% CI: 2.9-40.1 months) in the Durva/Treme + IR arm (p = 0.31). The majority of AEs were grades 1-2. CONCLUSION: Durva/Treme and Durva/Treme + IR showed similar efficacy. With a manageable safety profile. Larger studies are needed to fully characterize the efficacy of Durva/Treme ± IR in advanced BTC.

Dynamic Elevation of Aromatic Amino Acids in Hepatitis C Virus-Induced Cirrhosis After a Standard Meal.

INTRODUCTION: Perturbations in aromatic (AAAs) and branched-chain amino acids (BCAAs) are seen in decompensated liver disease. The aim of this study was to evaluate the dynamic, postprandial relationship between hepatitis C virus-induced liver disease and amino acid concentrations in patients with compensated liver disease. METHODS: Patients infected with hepatitis C virus underwent a baseline liver biopsy to determine Ishak Fibrosis Score and evaluate the liver transcriptome. Patients ate a standard meal and underwent peripheral vein sampling at defined intervals. Quantitative analysis of amino acids was performed using liquid chromatography-tandem mass spectrometry. RESULTS: At baseline, there was no difference in AAA and BCAA concentrations between patients with cirrhosis and non-cirrhotic patients. After a standard meal, AAAs, but not BCAAs, were elevated in patients with cirrhosis compared with non-cirrhotic patients at every time point. The HepQuant SHUNT fraction was significantly higher in patients with cirrhosis and positively correlated with AAA concentration at all time points, but not BCAA. Analysis of the hepatic transcriptome demonstrated greater downregulation of the AAA degradation pathways than the BCAA degradation pathways. DISCUSSION: At baseline, cirrhotic patients with compensated liver disease have adequate reserve liver function to metabolize AAAs and BCAAs. When faced with a metabolic stressor, such as a standard meal, patients with cirrhosis are less able to metabolize the increased load of AAAs. This impairment correlates with portosystemic shunting. Further evaluation of AAA levels in compensated liver disease might further the understanding of the liver-muscle axis and the role it may play in the development of sarcopenia in liver disease.

Liver biopsy for assessment of suspected drug-induced liver injury in metabolic dysfunction-associated steatohepatitis clinical trials: Expert consensus from the Liver Forum.

BACKGROUND: Causality assessment of suspected drug-induced liver injury (DILI) during metabolic dysfunction-associated steatohepatitis (MASH) clinical trials can be challenging, and liver biopsies are not routinely performed as part of this evaluation. While the field is moving away from liver biopsy as a diagnostic and prognostic tool, information not identified by non-invasive testing may be provided on histology. AIM: To address the appropriate utilisation of liver biopsy as part of DILI causality assessment in this setting. METHODS: From 2020 to 2022, the Liver Forum convened a series of webinars on issues pertaining to liver biopsy during MASH trials. The Histology Working Group was formed to generate a series of consensus documents addressing these challenges. This manuscript focuses on liver biopsy as part of DILI causality assessment. RESULTS: Expert opinion, guidance and recommendations on the role of liver biopsy as part of causality assessment of suspected DILI occurring during clinical trials for a drug(s) being developed for MASH are provided. Lessons learned from prior MASH programs are reviewed and gaps identified. CONCLUSIONS: Although there are no pathognomonic features, histologic evaluation of suspected DILI during MASH clinical trials may alter patient management, define the pattern and severity of injury, detect findings that favour a diagnosis of DILI versus MASH progression, identify prognostic features, characterise the clinicopathological phenotype of DILI, and/or define lesions that influence decisions about trial discontinuation and further development of the drug.

Digital pathology for nonalcoholic steatohepatitis assessment.

Histological assessment of nonalcoholic fatty liver disease (NAFLD) has anchored knowledge development about the phenotypes of the condition, their natural history and their clinical course. This fact has led to the use of histological assessment as a reference standard for the evaluation of efficacy of drug interventions for nonalcoholic steatohepatitis (NASH) - the more histologically active form of NAFLD. However, certain limitations of conventional histological assessment systems pose challenges in drug development. These limitations have spurred intense scientific and commercial development of machine learning and digital approaches towards the assessment of liver histology in patients with NAFLD. This research field remains an area in rapid evolution. In this Perspective article, we summarize the current conventional assessment of NASH and its limitations, the use of specific digital approaches for histological assessment, and their application to the study of NASH and its response to therapy. Although this is not a comprehensive review, the leading tools currently used to assess therapeutic efficacy in drug development are specifically discussed. The potential translation of these approaches to support routine clinical assessment of NAFLD and an agenda for future research are also discussed.

Erythrophagocytosis is not a reproducible finding in liver biopsies, and is not associated with clinical diagnosis of hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease with high mortality. Liver involvement is common (based on elevated liver function tests) with most patients demonstrating acute hepatitis. Liver biopsies are frequently obtained in the setting of suspected HLH for the purpose of identification of erythrophagocytosis, and if present, this finding is thought to suggest or support the diagnosis of HLH. However, there are problems with this approach; in particular, we do not know whether this finding is reproducible or whether it is specific to HLH. Therefore, we conducted a multi-institutional study in which experienced liver pathologists reviewed images taken from liver biopsies from patients with normal liver, acute hepatitis, possible HLH, and clinical HLH to determine if there was agreement about the presence or absence of erythrophagocytosis, and to ascertain whether the finding corresponds to a clinical diagnosis of HLH. Twelve liver pathologists reviewed 141 images in isolation (i.e., no clinical information or diagnosis provided). These came from 32 patients (five normal, 17 acute hepatitis, six HLH, four possible HLH). The pathologists classified each image as negative, equivocal, or positive for erythrophagocytosis. Kappa was .08 (no agreement) for case-level and 0.1 for image-level (1.4% agreement, based on two images which were universally considered negative). There was no difference in the proportion of pathologists who diagnosed erythrophagocytosis among those with different diagnoses at case or image-level (p = 0.82 and p = 0.82, respectively). Thus, erythrophagocytosis is an entirely unreliable histologic parameter in liver, as it is irreproducible and not demonstrably associated with a clinical disease (namely, HLH). Unless and until more reliable guidelines can be established, pathologists should refrain from commenting on the presence or absence of erythrophagocytosis in liver biopsy.

Prognostic factors in resolution of nonalcoholic fatty liver disease post bariatric surgery in adolescents.

BACKGROUND: The long-term effect of bariatric surgery on adolescent non-alcoholic fatty liver disease is not clear. OBJECTIVES: To evaluate longitudinal change in serum alanine aminotransferase (ALT) levels and to determine the factors independently associated with this change over 2 years after bariatric surgery in adolescents with severe obesity. SETTING: An observational prospective cohort from the Teen-LABS Consortium. METHODS: We examined the relationship of longitudinal change in serum ALT (% change and normalization) to change in body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), high- (HDL) and low-density lipoprotein cholesterol, A1C and fasting glucose, accounting for age, sex, race-ethnicity, blood pressure, and baseline BMI in 219 adolescents during the first 2 years post-surgery. RESULTS: Mean BMI declined from a baseline of 52.6 to 37.2 kg/m2 at 2 years (P < .01). Alanine aminotransferase decreased significantly from baseline (36.5 [95% CI: 31.4, 41.7]) to 6 months (30.5 [95% CI: 25.4, 35.6]), and remained stable at 12 and 24 months, all P < .01 versus baseline. After adjustment, improvement in BMI, fasting glucose, HOMA-IR, triglycerides, TG/HDL ratio, and HDL were independently associated with reduced ALT at 6 months. These remained significantly associated with a decline in ALT after adjusting for BMI change. The %participants with elevated ALT decreased from 71% at baseline to 42% and 36% at 1 and 2 years post-surgery. CONCLUSIONS: Bariatric surgery resulted in significant and sustained improvement in ALT levels over 2 years. Although associated with weight loss, this decline was also associated with improved metabolic indices, independent of weight loss.