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Cholangiocarcinoma represents the second most frequent type of primary liver cancer that develops through a multistep histopathologic sequence. Dysplasia in the biliary tract epithelium is a precursor lesion of cholangiocarcinoma. This review provides a practical overview of bile duct dysplasia in relation to invasive carcinoma, covering clinicopathological features, diagnostic criteria, differential diagnosis, useful testing modalities, and challenges in daily practice. The key features of biliary intraepithelial neoplasia, intraductal papillary neoplasm, intraductal tubulopapillary neoplasm, and mucinous cystic neoplasm are described. Important differential diagnoses are included. Common pitfalls in histopathologic interpretation of bile duct biopsies and frozen sections are discussed.

Objectives Primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) can be difficult to distinguish in end-stage liver disease. Previous studies have shown that immunoglobulin G (IgG) and immunoglobulin M (IgM) immunostaining can differentiate AIH from PBC in needle core biopsy specimens, and we seek to extend these data to cirrhotic liver explants, in which the histology of AIH or PBC may be indiscernible. Methods Clinical data were reviewed for 20 patients with PBC cirrhosis and 16 with AIH cirrhosis. Immunohistochemistry for IgM and IgG was performed on representative blocks of explanted livers. Three high-power fields with the highest concentration of IgG- and IgM-positive plasma cells were counted and compared. Results The average number of IgM-positive plasma cells was significantly higher in PBC explants (7.3) than in AIH (1.8) (P = .001). There was no significant difference in the average number of IgG-positive plasma cells in PBC (2.5) and AIH (2.8) (P = .8). The IgG/IgM ratio was more likely to be less than 1.0 in PBC (17/20, 85%) compared with AIH (7/16, 44%) (P = .01). Conclusions Our study demonstrates that the absolute number of IgM plasma cells is greater in explants of cirrhotic PBC compared with AIH. These findings may be helpful in the evaluation of cryptogenic cirrhosis.

Subtyping of hepatocellular adenoma (HCA) is an important task in practice as different subtypes may have different clinical outcomes and management algorithms. Definitive subtyping is currently dependent on immunohistochemical and molecular testing. The association between some morphologic/clinical features and HCA subtypes has been reported; however, the predictive performance of these features has been controversial. In this study, we attempted machine learning based methods to select an efficient and parsimonious set of morphologic/clinical features for differentiating a HCA subtype from the others, and then assessed the performance of the selected features in identifying the correct subtypes. We first examined 50 liver HCA resection specimens collected at the University of Washington and Kobe University/Kings College London, including HNF1α-mutated HCA (H-HCA) (n = 16), inflammatory HCA (I-HCA) (n = 20), beta-catenin activated HCA (β-HCA) (n = 8), and unclassified HCA (U-HCA) (n = 6). Twenty-six morphologic/clinical features were assessed. We used LASSO (least absolute shrinkage and selection operator) to select key features that could differentiate a subtype from the others. We further performed SVM (support vector machine) analysis to assess the performance (sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy) of the selected features in HCA subtyping in an independent cohort of liver resection samples (n = 20) collected at the University of Wisconsin-Madison. With some overlap, different combinations of morphologic/clinical features were selected for each subtype. Based on SVM analysis, the selected features classified HCA into correct subtypes with an overall accuracy of at least 80%. Our findings are useful for initial diagnosis and subtyping of HCA, especially in clinical settings without access to immunohistochemical and molecular assays.

Dysregulation of expression of functional genes and pathways plays critical roles in the etiology and progression of hepatocellular carcinoma (HCC). Next generation-based RNA sequencing (RNA-seq) offers unparalleled power to comprehensively characterize HCC at the whole transcriptome level. In this study, 17 fresh-frozen HCC samples with paired non-neoplastic liver tissue from Caucasian patients undergoing liver resection or transplantation were used for RNA-seq analysis. Pairwise differential expression analysis of the RNA-seq data was performed to identify genes, pathways, and functional terms differentially regulated in HCC versus normal tissues. At a false discovery rate (FDR) of 0.10, 13% (n = 4335) of transcripts were up-regulated and 19% (n = 6454) of transcripts were down-regulated in HCC versus non-neoplastic tissue. Eighty-five Kyoto Encyclopedia of Genes and Genomes pathways were differentially regulated (FDR,0.10), with almost all pathways (n = 83) being up-regulated in HCC versus non-neoplastic tissue. Among the top up-regulated pathways was oxidative phosphorylation (hsa00190; FDR, 1.12E-15), which was confirmed by Database for Annotation, Visualization, and Integrated Discovery (DAVID) gene set enrichment analysis. Consistent with potential oxidative stress due to activated oxidative phosphorylation, DNA damage-related signals (e.g., the up-regulated hsa03420 nucleotide excision repair [FDR, 1.14E-04] and hsa03410 base excision repair [FDR, 2.71E-04] pathways) were observed. Among down-regulated genes (FDR,0.10), functional terms related to cellular structures (e.g., cell membrane [FDR, 3.05E-21] and cell junction [FDR, 2.41E-07], were highly enriched, suggesting compromised formation of cellular structure in HCC at the transcriptome level. Interestingly, the olfactory transduction (hsa04740; FDR, 1.53E-07) pathway was observed to be down-regulated in HCC versus non-neoplastic tissue, suggesting impaired liver chemosensory functions in HCC. Our findings suggest oxidative phosphorylation and the associated DNA damage may be the major driving pathologic feature in HCC.

The prevalence of non-alcoholic fatty liver disease (NAFLD) and its progression to non-alcoholic steatohepatitis (NASH) is higher in postmenopausal women than men. The aim of this study was to determine the molecular mechanisms underlying this sexual dimorphism in NAFLD.A total of 24 frozen liver samples of both sexes (normal and NAFLD/NASH) were used in this study. Total RNAseq was first used to identify differentially expressed genes (DEGs) between samples. Enrichment analysis of Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome were used to analyze biological pathways. RTWe identified 4362 genes that are differentially expressed between NAFLD/NASH and normal samples; of those 745 genes were characterized as sex specific in NAFLD/NASH. Multiple pathway analysis platforms showed that Wnt-signaling is a candidate shared for a common biological pathway-associated with NAFLD/NASH. Using Wnt pathway focused PCR array we identified many genes involved in canonical pathway (Wnt/β-catenin activation) such as CTNNB1, c-Myc and CCND2 are overexpressed in female cases, whereas these genes are either not detected or downregulated in male cases. Immunoblot analysis validated the expression of CTNNB1 in female cases but not in male protein samples.Our study suggests, for the first time, that the activation of canonical Wnt signaling could be one of the main pathways associated with sexual dimorphism in NAFLD and NASH.

Proprotein convertase subtilisin/kexin type 9 (Pcsk9) binds to hepatic low-density lipoprotein receptor (LDLR) and induces its internalization and degradation. Pcsk9 inhibition increases LDLR expression by hepatocytes, which causes increased uptake of circulating LDL, thereby reducing plasma LDL-cholesterol. However, by increasing the uptake of LDL by the liver, Pcsk9 inhibition increases the exposure of the liver to cholesterol, which may result in higher risk of steatohepatitis and ever carcinogenesis. We compared Pcsk9-/- knockout (KO) mice and appropriate wild-type (WT) controls of the same strain assigned to a high-fat (15%, wt/wt) diet for 9 months supplemented with 0.25%, 0.5%, or 0.75% dietary cholesterol. Pcsk9 KO mice on a high-fat, high-cholesterol diet exhibited higher levels of hepatic free cholesterol loading and hepatic cholesterol crystallization than their WT counterparts. Pcsk9 KO mice developed crown-like structures of macrophages surrounding cholesterol crystal-containing lipid droplets and hepatocytes, exhibited higher levels of apoptosis, and developed significantly more hepatic inflammation and fibrosis consistent with fibrosing steatohepatitis, including 5-fold and 11-fold more fibrosis at 0.5% and 0.75% dietary cholesterol, respectively. When injected with diethylnitrosamine, a hepatic carcinogen, early-in-life Pcsk9 KO mice were more likely to develop liver cancer than WT mice. Conclusion: Pcsk9 KO mice on high-cholesterol diets developed increased hepatic free cholesterol and cholesterol crystals and fibrosing steatohepatitis with a higher predisposition to liver cancer compared with WT mice. Future studies should evaluate whether patients on long-term treatment with anti-PSCK9 monoclonal antibodies are at increased risk of hepatic steatosis, steatohepatitis or liver cancer, while accounting for concurrent use of statins.

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are biliary tract pathologies with increased risk of HCC, although HCC is more commonly associated with viral hepatitis and steatohepatitis. HCC risk stratification in PBC/PSC populations may help select patients for surveillance. We hypothesized that metabolic syndrome associated diagnoses and co-morbid nonalcoholic fatty liver disease (NAFLD) may be risk factors for HCC in patients with PBC and PSC. We undertook a multi-institutional case control study of PSC (19 cases, 38 controls) and PBC (39 cases and controls) patients with advanced fibrosis, matched for known HCC risk factors of age and sex, who had native liver explant or resection specimens. In the PSC population, HCC risk was significantly associated with multiple metabolic syndrome associated diagnoses (OR 13, p = 0.02), hyperlipidemia (OR 29, p = 0.03), and obesity (OR 6.8, p = 0.01). In the PBC cohort, only type 2 diabetes was a risk factor for HCC (OR 4.7, p = 0.03). In the PSC cohort, thick fibrous septae were associated with HCC risk (OR 3.4, p = 0.04). No other pathologic features of the nonneoplastic liver were significantly associated with HCC, including features of NAFLD such as macrovesicular steatosis, pericellular fibrosis, and steatohepatitis. Metabolic syndrome associated diagnoses, specifically type 2 diabetes among PBC patients, is associated with HCC risk in patients with biliary type cirrhosis. However, we found no evidence that HCC risk is related to co-morbid NAFLD, indicating a likely distinct mechanism of metabolic syndrome-associated carcinogenesis in these populations.

Mismatch repair (MMR) immunohistochemistry (IHC) is frequently used to inform prognosis, select (immuno-)therapy, and identify patients for heritable cancer syndrome testing. However, false-negative and false-positive MMR IHC interpretations have been described.Following identification of discordant MMR IHC and DNA-based microsatellite instability testing in a patient with colorectal carcinoma, we retrospectively reviewed institutional archives to identify patient samples with similar discrepancies.We report a patient with metastatic colorectal carcinoma who initially received immunotherapy on the basis of apparent isolated loss of MLH1 by IHC; notably,This study confirms that rare germline polymorphisms can result in incorrect IHC results, potentially affecting selection of optimal therapy and the decision to pursue germline testing. This case further highlights the need for expert molecular pathologic review and communication between clinical and molecular oncology teams.

PURPOSE Mismatch repair (MMR) immunohistochemistry (IHC) is frequently used to inform prognosis, select (immuno-)therapy, and identify patients for heritable cancer syndrome testing. However, false-negative and false-positive MMR IHC interpretations have been described. MATERIALS AND METHODS Following identification of discordant MMR IHC and DNA-based microsatellite instability testing in a patient with colorectal carcinoma, we retrospectively reviewed institutional archives to identify patient samples with similar discrepancies. RESULTS We report a patient with metastatic colorectal carcinoma who initially received immunotherapy on the basis of apparent isolated loss of MLH1 by IHC; notably, MLH1 promoter hypermethylation was negative. Subsequent evaluation of neoplastic tissue on a DNA-based targeted next-generation sequencing panel demonstrated microsatellite stability, low tumor mutational burden, and a benign MLH1 variant, MLH1 p.V384D, accompanied by loss of heterozygosity. The constellation of findings and repeat MLH1 IHC demonstrating retained expression using a different antibody-clone, supported reclassification of the neoplasm as MMR-proficient. Immunotherapy was discontinued, and cytotoxic chemotherapy was initiated. This index case of apparent discordance between MMR IHC and DNA-based microsatellite instability prompted a retrospective review of institutional archives to identify patient samples with similar discrepancies. Further evaluation of neoplasms harboring MLH1 p.V384D with loss of heterozygosity revealed systematic antibody-dependent interference. The review also identified a second IHC-interference candidate, MLH1 p.A441T. CONCLUSION This study confirms that rare germline polymorphisms can result in incorrect IHC results, potentially affecting selection of optimal therapy and the decision to pursue germline testing. This case further highlights the need for expert molecular pathologic review and communication between clinical and molecular oncology teams.

Hepatocellular neoplasms can develop in multiple genetic metabolic disorders. While there have been rare case reports, clinical and pathological characterizations have not been systematically performed. We conducted a retrospective study in 9 patients with these rare genetic metabolic disorders, including glycogen storage disease type 1, ornithine carbamyl transferase deficiency, hereditary tyrosinemia type 1, and Navajo neurohepatopathy, who developed hepatocellular neoplasms. Our results show that steatosis is a common finding in both tumor (6/9 cases, 67%) and background liver parenchyma (8/9 cases, 89%), underlying a possible role for steatosis in tumorigenesis in these genetic metabolic disorders. Our findings also raise a consideration of underlying genetic metabolic disorder when young patients with hepatocellular neoplasm show steatosis in both the tumor and background liver.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in North America and Europe, with increasing prevalence in other regions of the world. Its spectrum encompass steatosis, non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. It is considered as the manifestation of metabolic syndrome in liver, and its development and progression is influenced by complex interaction of environmental and genetic factors. In this review we discuss the histopathological features, differential diagnoses, and the commonly used grading and staging systems of NAFLD. NAFLD associated with other diseases, histological changes after therapeutic intervention and recurrence or occurrence of NAFLD after liver transplantation are also addressed.

Summary Intraductal biopsy is commonly used for preoperative evaluation of the etiology of biliary strictures. Interpretation of intraductal biopsies is frequently challenging. The diagnosis often suffers from interobserver disagreement, which has not been studied in the literature. We sought to assess interobserver concordance in the interpretation of intraductal biopsies. Eighty-five biopsies were retrieved, falling into five diagnostic categories: negative for dysplasia (NED), indefinite for dysplasia (IND), low-grade dysplasia (LGD), high-grade dysplasia (HGD), and carcinoma (CA). Eight gastrointestinal pathologists blindly reviewed all the slides. Agreement among pathologists was analyzed using Fleiss κ and weighted concordance coefficient S∗. A face-to-face consensus/training session was held to discuss the classification criteria, followed by a second round review. The overall interobserver agreement was fair in the first round review (κ = 0.39; S∗ = 0.56) and improved to moderate in the second round review (κ = 0.48; S∗ = 0.69). The agreement before and after consensus meeting was substantial to nearly perfect for CA (κ = 0.65, S∗ = 0.83; and κ = 0.80, S∗ = 0.91), fair for HGD (κ = 0.28, S∗ = 0.69; and κ = 0.40, S∗ = 0.63), and moderate for NED (κ = 0.47, S∗ = 0.50; and κ = 0.47, S∗ = 0.53). Agreement improved from fair to moderate for LGD (κ = 0.36, S∗ = 0.61; and κ = 0.49, S∗ = 0.71) and slight to fair for IND (κ = 0.16, S∗ = 0.51; and κ = 0.33, S∗ = 0.50). Compared with Hollande's fixed specimens, the agreement was higher in almost all diagnostic categories in formalin-fixed biopsies. Overall, interobserver concordance was improved after a consensus/training session. Interobserver reproducibility was high at the end of the diagnostic spectrum (CA) but fair to moderate for other diagnostic categories.

Hepatic adenomas occur most commonly in women between the ages of 20 and 40 years, but rarely they occur in older aged persons, including those 60 years of age or older. This group of adenomas, however, has not been systemically examined. Twenty-six hepatic adenomas in persons 60 years of age or older were studied, along with a control group of 50 hepatic adenomas in persons aged 30 to 39. Hepatic adenomas in persons 60 or more years of age were found in 21 women and 5 men, while the control group had 44 women and 6 men. Subtyping the adenomas in persons 60 years or older showed the following results: 18 HNF1A-inactivated adenomas (69%), 4 inflammatory adenomas (15%), and 4 unclassified adenomas (15%). In contrast, the control group showed a significantly different pattern (P=0.003), with a greater percentage of inflammatory adenomas (28, 56%), fewer HNF1A-inactivated adenomas (8, 16%), and more unclassified adenomas (14, 28%). Atypia and malignant transformation within the hepatic adenomas was studied next. Of the hepatic adenomas in persons age 60 or greater, 3 (12%) showed atypical histologic features, and 6 (23%) had a malignant transformation. In contrast, for hepatic adenomas in the control group, only 4 (8%) adenomas showed atypical histologic features, and 3 (6%) had undergone malignant transformation. In addition, the hepatic adenomas that were atypical or showed early malignant transformation were less likely to have beta-catenin activation in patients over 60 (2/9 cases) compared with those between 30 and 39 years (5/7 cases). Myxoid change and heavy lipofuscin deposition were also more common in adenomas in older aged persons. In conclusion, hepatic adenomas in persons 60 years of age or older are enriched for HNF1A-inactivated adenomas and have a higher frequency of malignant transformation. Malignant transformation, however, is less likely to develop through activation of the beta-catenin pathway.

Our aims were to assess performance of duodenal intraepithelial lymphocyte counting for diagnosis of Helicobacter pylori (H. pylori) gastritis, and effects of eradication therapy on intraepithelial lymphocytosis. Paired duodenal and gastric biopsies from subjects with a pathologic diagnosis of H. pylori gastritis were reviewed. Higher duodenal intraepithelial lymphocyte counts were observed in 40 subjects with H. pylori gastritis (26 ± 5 per villus) than 52 subjects negative for H. pylori (12 ± 2 per villus). After successful eradication therapy, duodenal lymphocytes were indistinguishable from H. pylori–negative subjects, whereas they remained elevated after failed eradication therapy. This study confirms previous reports of increased duodenal intraepithelial lymphocytes in patients with concurrent Helicobacter pylori gastritis. Intraepithelial lymphocyte counts of > 15 per villus or > 10 per 100 enterocytes were predictive of infection. Duodenal lymphocytosis decreases significantly after successful eradication therapy but remains elevated when treatment fails.

Obesity and type 2 diabetes increase hepatocellular carcinoma (HCC) incidence in humans and accelerate diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. We investigated whether exercise reduces HCC development in obese/diabetic Alms1 mutant (foz/foz) mice and studied protective mechanisms.We measured HCC development in DEN-injected male foz/foz and wild-type (WT) littermates housed with or without an exercise wheel from week 4 until 12 or 24 weeks, and in foz/foz mice pair-fed to WT littermates. We also studied HCC development in DEN-injected Jnk1Exercising foz/foz mice maintained similar weight as WT mice up to 10 weeks, but then gained weight and were obese by 24 weeks; a similar body weight profile was obtained by pair-feeding foz/foz mice to WT. At 12 weeks, livers of exercising foz/foz mice exhibited fewer GST-pi positive hepatocytes than sedentary counterparts; by 24 weeks, fewer exercising foz/foz mice developed HCC (15% vs. 64%, p0.05). Conversely, pair-feeding foz/foz mice failed to reduce HCC incidence. In these insulin-resistant foz/foz mice, exercise failed to activate hepatic AMPK or Akt/mTORC1. Instead, it improved insulin sensitivity, ameliorated steatosis and liver injury, activated p53 to increase p27 expression, and prevented JNK activation. This was associated with suppression of hepatocellular proliferation. DEN-injected Jnk1Direct effects of exercise dampen proliferation of dysplastic hepatocytes to reduce 3-month dysplastic foci and 6-month incidence of DEN-induced HCC in obese, insulin-resistant mice. The effects of exercise that potentially slow hepatocarcinogenesis include p53-mediated induction of p27 and prevention of JNK activation.Fatty liver disease commonly occurs alongside obesity and diabetes, contributing to rapidly increasing rates of liver cancer throughout the world. Herein, we show that exercise reduces the incidence and progression of hepatocellular carcinoma in mouse models. The effect of exercise on cancer risk was shown to be independent of changes in weight. Exercise could be a protective mechanism against liver cancer in at-risk individuals.

The etiology and incidence of cirrhosis in adults has been well studied, however there is scant data in younger patients. The aim of this study was to determine causes of cirrhosis in patients ≤40 years old. In this multi-institutional retrospective study, pathology databases were searched for patients ≤40-year-old with a diagnosis of cirrhosis from 1995 to 2018. Clinical charts and pathology reports were reviewed to identify etiologies of cirrhosis in each case. The patients were divided into 4 age groups (1, 1- 5, 5- 18, and 18-40 years old) for further analysis. We identified 594 patients (264 female, 330 male). Among18-year-old patients, congenital cholestatic diseases and developmental disorders were the most common causes of cirrhosis (50.2%, 172/342). Metabolic and genetic diseases were also seen more commonly in this age group (16.6%, 57/342). In contrast, viral hepatitides were the most common cause of cirrhosis in 18-40-year-old patients (39.6%, 100/252) followed by autoimmune and fatty liver disease (22.2%, 56/252 and 15.07%, 38/252, respectively). Cryptogenic cirrhosis (overall 7.2%, 42/594) was seen in 3% (4/133), 1.4% (1/69), 10.7% (15/140) and 8.7% (22/252) of patients aged1, 1- 5, 5- 18, and 18-40 years, respectively. Developmental and metabolic disorders are the most common causes of cirrhosis in children (18), while viral hepatitides are leading causes in adolescents and young adults (18-40) similar to adults. The incidence of cryptogenic cirrhosis also varies depending on the age, being lowest in 1- 5 year and highest in 5- 18 year age group children.

Centrizonal hepatocyte dropout has been described in diverse liver pathologies, including viral hepatitis, venous outflow obstruction, and allograft cellular rejection. However, its clinical significance remains uncertain.We designed a clinicopathological study of 206 allograft liver biopsies with centrizonal hepatocyte dropout. Centrizonal hepatocyte dropout was associated most frequently with cellular rejection (n = 62), asymptomatic/protocol biopsies (n = 56), immediate post-transplantation biopsies (n = 21), biliary obstruction (n = 14), and viral hepatitis (n = 13). The differential diagnosis is informed by timing post-transplantation, biliary imaging and laboratory test results. 'Cholestatic' and 'hepatocytic' laboratory patterns were associated with biliary obstruction and cellular rejection, respectively. A mixed pattern peaking after biopsy was observed in viral hepatitis cases. In the context of cellular rejection, dropout was not associated with the time interval to normalisation of serum alanine aminotransferase (ALT), but was associated with shorter transplant-free survival (hazard ratio 4, P = 0.01) than that of histological severity-matched controls. In time zero allograft biopsies, time to ALT normalisation was prolonged (median, 15 versus 11 days, P = 0.002) in allografts with centrizonal dropout, with no effect on retransplant-free survival.Centrizonal hepatocyte dropout has low clinicopathological diagnostic specificity. However, it correlates with adverse clinical outcomes in allograft cellular rejection and time zero biopsies.

Gallbladder carcinoma is an uncommon malignancy with an overall 5-year survival of less than 5%. Gallbladder carcinoma has been strongly linked with cholelithiasis and chronic inflammation. Case reports and series have described cholecystitis with acute (neutrophilic) inflammation in association with gallbladder carcinoma, although a clear relationship to patient outcome has not been established. Our series included 8 cases of gallbladder carcinoma with high tumor-associated neutrophils (>25 per high power field) that were associated with shorter patient survival (Cox regression coefficient 6.2, p = 0.004) than age- and stage-matched controls. High tumor-associated neutrophils were not associated with gallbladder rupture/perforation or increased bacterial load measured by 16S PCR. Neutrophilic inflammation with gallbladder carcinoma correlates to shorter survival, independent of patient age and stage of carcinoma. The findings suggest that the degree of neutrophilic inflammation may have prognostic significance in specimens from patients with gallbladder carcinoma after cholecystectomy. Further studies with larger case numbers are needed to confirm and generalize these findings.

Immune checkpoint inhibitors (ICIs) represent a promising therapy for many types of cancer. However, only a portion of patients respond to this therapy and some patients develop clinically significant immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI), an immune-related adverse event (irAE) that may require the interruption or termination of treatment and administration of systemic corticosteroids or other immunosuppressive agents. Although the incidence of ILICI is lower with monotherapy, the surge in combining ICIs with chemotherapy, targeted therapy, and combination of different ICIs has led to an increase in the incidence and severity of ILICI - a major challenge for development of effective and safe ICI therapy. In this review, we highlight the importance and contribution of the liver microenvironment to ILICI by focusing on the emerging roles of resident liver cells in modulating immune homeostasis and hepatocyte regeneration, two important decisive factors that dictate the initiation, progression, and recovery from ILICI. Based on the proposed contribution of the liver microenvironment on ICILI, we discuss the clinical characteristics of ILICI in patients with preexisting liver diseases, as well as the challenges of identifying prognostic biomarkers to guide the clinical management of severe ILICI. A better understanding of the liver microenvironment may lead to novel strategies and identification of novel biomarkers for effective management of ILICI.

Gastric intestinal metaplasia (GIM) is a known premalignant condition of the human stomach along the pathway to gastric cancer (GC). Histologically, GIM represents the replacement of normal gastric mucosa by mucin-secreting intestinal mucosa. Helicobacter pylori infection is the most common etiologic agent of GIM development worldwide. The prevalence of GIM is heterogeneous among different regions of the world and correlates with the population endemicity of H. pylori carriage, among other environmental factors. GC remains the third leading cause of cancer-related mortality globally. GIM is usually diagnosed by upper endoscopy with biopsy, and histologic scoring systems have been developed to risk-stratify patients at highest risk for progression to GC. Several recent endoscopic imaging modalities may improve the optical detection of GIM and early GC. Appropriate surveillance of GIM may be cost effective and represents an opportunity for the early diagnosis and therapy of GC. Certain East Asian nations have established population-level programs for the screening and surveillance of GIM; guidelines regarding GIM surveillance have also recently been published in Europe. By contrast, few data exist regarding the appropriateness of surveillance of GIM in the United States. In this review, we discuss the pathogenesis, epidemiology, diagnosis, and management of GIM with an emphasis on the role of appropriate endoscopic surveillance.

Copper is an indispensable trace element. It serves as a cofactor for enzymes involved in cellular energy metabolism, antioxidant defense, iron transport, and fibrogenesis. Although these processes are central in the pathogenesis of liver disorders, few studies have attributed them to copper deficiency. We herein describe in detail a case series of liver disease patients (n = 12) who presented with signs of copper deficiency based on serum and liver copper measurements. Median age of the group at the time of presentation was 39 (range 18‐64 years). Six patients were female. The median serum copper was 46 μg/dL (normal range: 80‐155 μg/dL for women and 70‐140 μg/dL for men). Seven of the 12 patients had hepatic copper concentration less than 10 μg/g dry weight (normal range: 10‐35 μg/g). Most cases presented with acute‐on‐chronic liver failure (n = 4) and decompensated cirrhosis (n = 5). Only 3 patients had a condition known to be associated with copper deficiency (ileocolonic Crohn’s disease following resection n = 1, Roux‐en‐Y gastric bypass n = 2) before presenting with hepatic dysfunction. Notable clinical features included steatohepatitis, iron overload, malnutrition, and recurrent infections. In 2 of the 3 patients who received copper supplementation, there was an improvement in serum copper, ceruloplasmin, and liver function parameters. Conclusion: Copper deficiency in the serum or liver occurs in a wide range of liver diseases. Given the biological essentiality of copper, the mechanism and clinical significance of this association require systematic study., This case series describes copper deficiency in the serum and liver tissue in patients presenting with advanced liver diseases. We discuss the clinical implication of this phenomenon based on existing basic and translational studies. We also describe the effect of supplementation in three subjects.

Congestive hepatopathy is a complication of right heart failure and chronically elevated right heart pressure. Histologic findings include sinusoidal dilatation, centrilobular hepatocellular plate atrophy, and fibrosis. We performed a validation study of a recently proposed scoring system (0 to 4 scale) for congestive hepatic fibrosis on 38 liver biopsies. Glutamine synthetase immunohistochemistry was also performed, and loss of centrizonal immunoreactivity correlated with increasing fibrosis score (P

Immune checkpoint inhibitors (ICIs) represent a promising therapy for many types of cancer. However, only a portion of patients respond to this therapy and some patients develop clinically significant immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI), an immune-related adverse event (irAE) that may require the interruption or termination of treatment and administration of systemic corticosteroids or other immunosuppressive agents. Although the incidence of ILICI is lower with monotherapy, the surge in combining ICIs with chemotherapy, targeted therapy, and combination of different ICIs has led to an increase in the incidence and severity of ILICI - a major challenge for development of effective and safe ICI therapy. In this review, we highlight the importance and contribution of the liver microenvironment to ILICI by focusing on the emerging roles of resident liver cells in modulating immune homeostasis and hepatocyte regeneration, two important decisive factors that dictate the initiation, progression, and recovery from ILICI. Based on the proposed contribution of the liver microenvironment on ICILI, we discuss the clinical characteristics of ILICI in patients with preexisting liver diseases, as well as the challenges of identifying prognostic biomarkers to guide the clinical management of severe ILICI. A better understanding of the liver microenvironment may lead to novel strategies and identification of novel biomarkers for effective management of ILICI.

Objectives Histopathologic evaluation of bile biopsies for biliary strictures is frequently challenging and is affected by interobserver disagreement. Reliable ancillary tests that can help differentiate benign from malignant are not available. This study aimed to evaluate whether DNA content abnormalities detected by flow cytometry on formalin-fixed, paraffin-embedded (FFPE) tissue can help differentiate benign/reactive, dysplastic from malignant cell populations in bile duct biopsies. Methods We performed DNA flow cytometry on 30 FFPE bile duct biopsies in 5 well-defined diagnostic categories: (1) negative for dysplasia (NED), (2) low-grade dysplasia (LGD), (3) high-grade dysplasia (HGD), (4) carcinoma (CA), and (5) indefinite for dysplasia (IND). Results Abnormal DNA content was detected in 0 NED, 5 LGD (62.5%), 2 HGD (33.3%), 3 CA (60%), and 4 IND (80%) samples. As a diagnostic marker, the estimated sensitivity, specificity, positive predictive value, and negative predictive value were 63%, 100%, 100%, and 50%, respectively, for diagnosing HGD or CA. Conclusions DNA flow cytometry analysis is a useful ancillary test for the interpretation of bile duct biopsies. DNA content abnormalities, when correlated with histologic findings, will not only help confirm the morphologic impression but also identify patients who are at a higher risk of developing malignancy.

Hepatocellular adenomas are rare in children. A large study focused on pediatric patients has not been undertaken. A natural language search was performed at 5 institutions for hepatocellular adenomas in patients less than 21 years old. Clinical characteristics as well as immunohistochemical staining profile was reviewed and adenomas subtyped per standard classification. Patients were divided into pre- and post-pubescent age group. Thirty-one patients were included. 11 (35%) were male and 10 (32%) were pre-pubescent. 15 (54%) of 28 patients with known clinical histories had adenomas associated with a syndrome. The percentage of the different adenoma subtypes was: 23% β-catenin activated, 3% combined inflammatory and β-catenin activated, 29% HFN1α-inactivated, 35% inflammatory, and 10% unclassified subtype by immunohistochemical staining. Interestingly 47% of patients with syndromes were male, while 85% of patients in the non-syndromic group were female. The total number of β-catenin activated tumors was greater in the syndromic group (5 of 15, 33%) and pre-pubescent group (5 of 10, 50%) than in the non-syndromic group (2 of 13, 16%) and post-pubescent group (3 of 21, 14%), p=0.4 and p=0.07 respectively. Inflammatory type adenoma was more frequent in the post-pubescent (10 of 21, 48%) than in the pre-pubescent group (1 of 10, 10%), p=0.06, trending towards significance. Pediatric patients with hepatocellular adenomas frequently have syndromes, especially in the pre-pubescent group. In patients with syndromes a greater percentage of adenomas were β-catenin activated. In patients without a known syndrome the distribution of hepatocellular adenoma sub-types appears similar to adults.

Hepatitis B infection can cause a wide range of histopathological changes in the liver with different presentations during the acute and chronic infection phases. These findings can often overlap with other viral and nonviral causes of hepatitis. Therefore, clinical information and serological findings are important in confirming the diagnosis of hepatitis B. Acute hepatitis B is not routinely biopsied as its histological findings are often nonspecific with hepatocyte injury, regeneration, inflammation, and necrosis. However, when acute hepatitis B progresses to chronic hepatitis B, histological examination of the liver biopsies plays a key role in guiding treatment decisions and surveillance for sequelae. Liver biopsy is currently the gold standard for evaluating the degree of fibrosis (stage) and necroinflammatory activity (grade) in chronic hepatitis B. In addition, monitoring for sequelae of chronic hepatitis B is important as chronic infection can lead to the development of cirrhosis and liver malignancies. The hepatitis B virus has been found to be causally linked to the development of hepatocellular carcinoma (HCC) and possibly associated with the development of cholangiocarcinoma. Active surveillance with imaging and liver biopsies can help with early detection of liver cancer to improve outcomes.

Our aims were to assess performance of duodenal intraepithelial lymphocyte counting for diagnosis of Helicobacter pylori (H. pylori) gastritis, and effects of eradication therapy on intraepithelial lymphocytosis. Paired duodenal and gastric biopsies from subjects with a pathologic diagnosis of H. pylori gastritis were reviewed. Higher duodenal intraepithelial lymphocyte counts were observed in 40 subjects with H. pylori gastritis (26 ± 5 per villus) than 52 subjects negative for H. pylori (12 ± 2 per villus). After successful eradication therapy, duodenal lymphocytes were indistinguishable from H. pylori-negative subjects, whereas they remained elevated after failed eradication therapy. This study confirms previous reports of increased duodenal intraepithelial lymphocytes in patients with concurrent Helicobacter pylori gastritis. Intraepithelial lymphocyte counts of 15 per villus or 10 per 100 enterocytes were predictive of infection. Duodenal lymphocytosis decreases significantly after successful eradication therapy but remains elevated when treatment fails.

ObjectivesOur aim was to investigate the frequency of steatohepatitic morphology in hepatocellular adenoma (HCA) and correlate with its clinical parameters and risk factors underlying nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH).MethodsWe examined a series of 41 liver resection specimens diagnosed with HCA for steatohepatitic changes. Background nonneoplastic liver was also evaluated. Clinical records were reviewed for risk factors of NAFLD/NASH.ResultsSix steatohepatitic HCAs (SH-HCAs) were identified, with an overall prevalence of six (14.6%) of 41, of which three were HNF1α inactivated and three were inflammatory, but none were β-catenin mutated. Five of the six patients with SH-HCA had at least one known risk factor for NAFLD/NASH, including obesity (n = 4; 66.7%), diabetes (n = 5; 83.3%), hypertension (n = 3; 50%), and dyslipidemia (n = 1; 16.7%). Compared with the patients without SH-HCA, the patients with SH-HCA had a higher frequency of type 2 diabetes, obesity, and hypertension. Of the six SH-HCAs, background nonneoplastic liver showed significant steatosis in three (50%) cases and steatohepatitic changes in one (16.7%) case.ConclusionsApproximately 15% of HCAs in our series demonstrated steatohepatitic changes. Lack of such morphology in β-catenin–mutated subtype suggests reassurance in this morphologic variant of HCA.

ObjectivesTo assess the concordance and performance characteristics of Helicobacter pylori laboratory tests compared with histopathology and to propose algorithms for the diagnosis of H pylori that minimize diagnostic error.MethodsH pylori diagnostics were reviewed from a 12-year period within a health system (2,560 cases). Analyses were performed to adjust diagnostic performance based on treatment and consensus histopathologic diagnoses among pathologists. Markers of access to care, including test cancellation frequency and turnaround time, were assessed. Costs and performance of candidate noninvasive testing algorithms were modeled as a function of disease prevalence.ResultsSerum H pylori IgG demonstrated a higher sensitivity (0.94) than urea breath and stool antigen tests (0.64 and 0.61, respectively). Evidence of an advantage in access to care for serology included a lower cancellation rate. Interobserver variability was higher (κ = 0.34) among pathologists for cases with a discordant laboratory test than concordant cases (κ = 0.56). A model testing algorithm utilizing serology for first-time diagnoses minimizes diagnostic error.ConclusionsAlthough H pylori serology has modestly lower specificity than other noninvasive tests, the superior sensitivity and negative predictive value in our population support its use as a noninvasive test to rule out H pylori infection. Reflexive testing with positive serology followed by either stool antigen or urea breath test may optimize diagnostic accuracy in low-prevalence populations.

Background The tumor microenvironment (TME) is critical to every aspect of cancer biology. Organotypic tumor slice cultures (TSCs) preserve the original TME and have demonstrated utility in predicting drug sensitivity, but the association between clinicopathologic parameters and in vitro TSC behavior has not been well-defined. Methods One hundred and eight fresh tumor specimens from liver resections at a tertiary academic center were procured and precisely cut with a Vibratome to create 250 μm × 6 mm slices. These fixed-dimension TSCs were grown on polytetrafluoroethylene inserts, and their metabolic activities were determined by a colorimetric assay. Correlation between baseline activities and clinicopathologic parameters was assessed. Tissue CEA mRNA expression was determined by RNAseq. Results By standardizing the dimensions of a slice, we found that adjacent tumor slices have equivalent metabolic activities, while those derived from different tumors exhibit >30-fold range in baseline MTS absorbances, which correlated significantly with the percentage of tumor necrosis based on histologic assessment. Extending this to individual cancers, we were able to detect intra-tumoral heterogeneity over a span of a few millimeters, which reflects differences in tumor cell density and Ki-67 positivity. For colorectal cancers, tissue CEA expression based on RNAseq of tumor slices was found to correlate with clinical response to chemotherapies. Conclusions We report a standardized method to assess and compare human cancer growth ex vivo across a wide spectrum of tumor samples. TSC reflects the state of tumor behavior and heterogeneity, thus providing a simple approach to study of human cancers with an intact TME.

The underlining mechanisms of dietary cholesterol and nonalcoholic steatohepatitis (NASH) in contributing to hepatocellular carcinoma (HCC) remain undefined. Here we demonstrated that high-fat-non-cholesterol-fed mice developed simple steatosis, whilst high-fat-high-cholesterol-fed mice developed NASH. Moreover, dietary cholesterol induced larger and more numerous NASH-HCCs than non-cholesterol-induced steatosis-HCCs in diethylnitrosamine-treated mice. NASH-HCCs displayed significantly more aberrant gene expression-enriched signaling pathways and more non-synonymous somatic mutations than steatosis-HCCs (335 ± 84/sample vs 43 ± 13/sample). Integrated genetic and expressional alterations in NASH-HCCs affected distinct genes pertinent to five pathways: calcium, insulin, cell adhesion, axon guidance and metabolism. Some of the novel aberrant gene expression, mutations and core oncogenic pathways identified in cholesterol-associated NASH-HCCs in mice were confirmed in human NASH-HCCs, which included metabolism-related genes (ALDH18A1, CAD, CHKA, POLD4, PSPH and SQLE) and recurrently mutated genes (RYR1, MTOR, SDK1, CACNA1H and RYR2). These findings add insights into the link of cholesterol to NASH and NASH-HCC and provide potential therapeutic targets., Nonalcoholic steatohepatitis (NASH) and dietary cholesterol are risk factors for hepatocellular carcinoma (HCC). Here, the authors utilise mouse models to show that dietary cholesterol induces NASH by deregulating genes involved in metabolism, inflammation and calcium signaling to induce NASH-HCC.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver tumor with neoplastic components of both hepatocytic and cholangiocytic differentiation. This unique neoplasm is gaining increasing recognition due to the intriguing pathology, tumor biology, and clinical behavior. It also poses challenges in diagnosis, treatment, and research, largely because of its histological and phenotypic diversity that lead to confusion in terminology and classification. There have been efforts attempting to unify the terminology of this neoplasm recently. Advances in investigation in various aspects have also been made. This review aims to update the terminology, classification, and clinical and pathological characteristics of cHCC-CCA.

Author(s): Brunt, Elizabeth; Aishima, Shinichi; Clavien, Pierre-Alain; Fowler, Kathryn; Goodman, Zachary; Gores, Gregory; Gouw, Annette; Kagen, Alex; Klimstra, David; Komuta, Mina; Kondo, Fukuo; Miksad, Rebecca; Nakano, Masayuki; Nakanuma, Yasuni; Ng, Irene; Paradis, Valerie; Nyun Park, Young; Quaglia, Alberto; Roncalli, Massimo; Roskams, Tania; Sakamoto, Michiie; Saxena, Romil; Sempoux, Christine; Sirlin, Claude; Stueck, Ashley; Thung, Swan; Tsui, WMS; Wang, Xin-Wei; Wee, Aileen; Yano, Hirohisa; Yeh, Matthew; Zen, Yoh; Zucman-Rossi, Jessica; Theise, Neil | Abstract: Primary liver carcinomas with both hepatocytic and cholangiocytic differentiation have been referred to as "combined (or mixed) hepatocellular-cholangiocarcinoma." These tumors, although described over 100 years ago, have attracted greater attention recently because of interest in possible stem cell origin and perhaps because of greater frequency and clinical recognition. Currently, because of a lack of common terminology in the literature, effective treatment and predictable outcome data have been challenging to accrue. This article represents a consensus document from an international community of pathologists, radiologists, and clinicians who have studied and reported on these tumors and recommends a working terminology for diagnostic and research approaches for further study and evaluation.ConclusionIt is recommended that diagnosis is based on routine histopathology with hematoxylin and eosin (HaE); immunostains are supportive, but not essential for diagnosis. (Hepatology 2018;68:113-126).

The adverse effects of immune checkpoint inhibitors in various organs may be attributed to immune-mediated processes triggered by disrupted self-tolerance; however, it remains unclear whether they are similar or dissimilar to classic organ-specific autoimmune diseases. The present study aimed to compare clinicopathologic features between checkpoint inhibitor-induced liver injury and acutely presenting autoimmune hepatitis or idiosyncratic drug-induced liver injury. Seven patients treated with nivolumab (n = 5) or ipilimumab (n = 2) presented with liver dysfunction a median of 41 days (range 21–120) after the initiation of immunotherapy. All patients had elevated liver enzymes, whereas hyper-bilirubinemia was less common. None of the patients had antinuclear antibodies or IgG elevations. Stopping the immunotherapy and additional immunosuppression with corticosteroids normalized or decreased liver enzymes in all patients treated. Histologically, all biopsies showed predominantly lobular hepatitis with milder portal inflammation. Centrilobular confluent necrosis and plasmacytosis were observed in a single case, and were markedly less common and milder than those in autoimmune hepatitis (p = 0.017 and p

Non-alcoholic steatohepatitis (NASH) is strongly associated with overnutrition, insulin resistance, and predisposition to type 2 diabetes. To critically analyze the translational significance of currently used animal models of NASH, we reviewed articles published during the last 3 years that studied NASH pathogenesis using mouse models. Among 146 articles, 34 (23%) used models in which overnutrition was reported, and 36 (25%) demonstrated insulin resistance, with or without glucose intolerance. Half the articles contained no information on whether mice exhibited overnutrition or insulin resistance. While 75 papers (52%) reported > 2-fold increase of serum/plasma alanine aminotransferase (ALT) compared with controls, ALT levels were near normal or not reported in 48%. Liver pathology was assessed by a pathologist with an interest in liver pathology in 53% of articles published in gastroenterology/hepatology journals, versus 43-44% in other journals. While there appears to be a trend to use models that are potentially relevant to the pathogenesis of human NASH, journals currently publish data on mouse models in which overnutrition and insulin resistance do not occur, without ALT increase or appropriate analysis of NASH pathology. We recommend that investigators, reviewers, and journal editors carefully consider the validity of NASH models in current use and that moves are made to reach a consensus on what the minimal criteria should be.

AIMS Cellular senescence plays a role in tumour suppression and in the pathogenesis of various non-neoplastic diseases, including primary biliary cholangitis and other adult cholangiopathies. Less is known about the role of cellular senescence in cholangiopathies in children. With that in mind, we examined the expression of senescence-associated cell cycle regulators in biliary atresia, the most common form of paediatric obliterative cholangiopathy. METHODS AND RESULTS The expression of senescence-associated cell cycle regulators (p16Ink4a and p21WAF1/Cip1 ) and a ductular reaction related marker (neural cell adhesion molecule: NCAM) was examined in bile ducts and bile ductules in liver samples taken from the patients with biliary atresia [n = 80; including 23 samples at the time of the Kasai procedure (KP) and 63 obtained from the explanted liver (LT) (six cases with samples at both surgical stages of disease)] and from appropriate controls (n = 17). The degree of ductular reaction and cholestasis was significantly more extensive in LT than KP (P < 0.01). The expression of p16INK4a and NCAM was significantly more extensive in bile ducts and bile ductules in ductular reaction in both KP and LT compared to controls and in LT compared to KP (P < 0.05). The expression of p21WAF1/Cip1 was significantly more extensive in bile ducts and bile ductules in KP compared to both LT and controls (P < 0.01). CONCLUSIONS Cellular senescence may play a role in the progression of bile duct loss in biliary atresia in a manner similar to that of adult cholangiopathies.

Aims Gallbladder carcinomas usually present in advanced stages and has a dismal prognosis despite modern imaging techniques and aggressive surgical intervention. Identification of biologic markers for early diagnosis and improved therapeutic strategies is thus of paramount importance. S100P has been identified in a variety of malignant neoplasms of the gastrointestinal and pancreaticobiliary systems, but it is not yet known if S100P expression is associated with clinically-relevant characteristics of gall bladder carcinoma. The aims of the present study were: 1) to investigate the relationship between S100P expression and histological type, grade, tumor-node-metastasis stage, presence of vascular invasion, perineural invasion and necrosis; and 2) to evaluate for any S100P-defined difference in the risk for tumor recurrence or death. Method Immunostains for S100P were performed on 4 tissue microarray blocks containing 91 cases of gall bladder carcinoma. Result The intensity of S100P staining was significantly associated with pathological T stage 4 (p = 0. 0238). Staining intensity ≥3 in ≥25% tumor cells was associated with pathological T stage 4 (p = 0.0005). A higher S100P immunoreactivity score (IRS) was significantly associated with higher TNM stage (p = 0.0341). Age (p = 0.0485), presence of vascular invasion (p = 0.0359), pathological T stage (p = 0.0291) and TNM stage (p = 0.0153) were significantly associated with tumor recurrence. Intense S100P reactivity was associated with decreased overall survival [hazard ratio = 9.614; 95% confidence interval (CI), 1.873–49.338; p = 0.0067]. Conclusion Our findings indicate that S100P over-expression is a potential prognostic marker for gall bladder carcinoma and is significantly associated with advanced tumor stage and poorer survival.

Orthotopic liver transplantation is the best option for patients with carefully selected unresectable disease because of underlying liver dysfunction. The 5-year survival rate after orthotopic liver transplantation for early detected hepatocellular carcinoma (HCC) is high, and a similar or even higher rate is reported in those with radiologically undetected HCC. This study evaluated and compared the histologic features of pretransplant radiologically undetected (14 patients, 25 tumors) versus detected (36 patients, 45 tumors) HCCs. Tumor size, tumor differentiation, number of unpaired arteries, mitotic count per 10 high-power fields, CD34 immunostain to assess microvessel density, and Ki67 immunostain were compared with the Liver Imaging Reporting and Data System score, which was retrospectively assigned to each tumor in both groups. The Liver Imaging Reporting and Data System score was significantly higher in the HCC detected group (P

Nonalcoholic fatty liver disease (NAFLD) occurs with higher prevalence in patients with inflammatory bowel disease (IBD) relative to the general population, and susceptibility is related to the metabolic syndrome, as well as higher prevalence of bowel resection and gut microbiotal factors. Liver complications, including NAFLD and primary sclerosing cholangitis (PSC), contribute to treatment and prognosis of patients with IBD. However, the potential interplay of NAFLD and PSC is not well understood. We retrospectively assessed severity of steatosis and steatohepatitis in liver specimens from 49 patients with IBD only, 44 with IBD and comorbid PSC, and 30 with IBD and PSC after liver transplantation. Patients with IBD had higher prevalence of at least grade 1 steatosis (59%) than IBD and PSC (11%), or IBD and PSC posttransplant (3%) (P < .001). The average severity of steatosis was 25% ± 8% (95% confidence interval) for IBD only, 3% ± 1% for comorbid IBD and PSC, and 1% ± 1% for IBD and PSC posttransplant (P < .001). Steatohepatitis was significantly higher in IBD only (12%) than in IBD and PSC ± transplant (0%) (P = .01). Despite these differences in susceptibility to NAFLD, the 3 populations had statistically indistinguishable average body mass index and total cholesterol and prevalence of hypertension, diabetes, and alcohol use. Multivariate regression modeling revealed body mass index, hypertension, and diabetes as significant correlates to NAFLD severity in all studied populations. In conclusion, patients with comorbid IBD and PSC have significantly less susceptibility to NAFLD than those with IBD alone, despite similar prevalence of major NAFLD risk factors.

// Matthew M. Yeh 1 , Sarag Boukhar 1 , Benjamin Roberts 2 , Nairanjana Dasgupta 3 and Sayed S. Daoud 4 1 Department of Pathology, University of Washington School of Medicine, Seattle, WA 98195, USA 2 The Liver Center, University of Kansas Medical Center, Kansas City, KS 66160, USA 3 Department of Mathematics and Statistics, Washington State University, Pullman, WA 99164, USA 4 Department of Pharmaceutical Sciences, Washington State University Health Sciences, Spokane, WA 99210, USA Correspondence to: Sayed S. Daoud, email: daoud@wsu.edu Keywords: hepatitis C, racial disparity, genomic variants, hepatocellular carcinoma, alternative splicing Received: November 30, 2016 Accepted: July 03, 2017 Published: August 01, 2017 ABSTRACT Chronic liver diseases are one of the major public health issues in United States, and there are substantial racial disparities in liver cancer-related mortality. We previously identified racially distinct alterations in the expression of transcripts and proteins of hepatitis C (HCV)-induced hepatocellular carcinoma (HCC) between Caucasian (CA) and African American (AA) subgroups. Here, we performed a comparative genome-wide analysis of normal vs . HCV+ (cirrhotic state), and normal adjacent tissues (HCCN) vs . HCV+HCC (tumor state) of CA at the gene and alternative splicing levels using Affymetrix Human Transcriptome Array (HTA2.0). Many genes and splice variants were abnormally expressed in HCV+ more than in HCV+HCC state compared with normal tissues. Known biological pathways related to cell cycle regulations were altered in HCV+HCC, whereas acute phase reactants were deregulated in HCV+ state. We confirmed by quantitative RT-PCR that SAA1 , PCNA-AS1 , DAB2 , and IFI30 are differentially deregulated, especially in AA compared with CA samples. Likewise, IHC staining analysis revealed altered expression patterns of SAA1 and HNF4α isoforms in HCV+ liver samples of AA compared with CA. These results demonstrate that several splice variants are primarily deregulated in normal vs . HCV+ stage, which is certainly in line with the recent observations showing that the pre-mRNA splicing machinery may be profoundly remodeled during disease progression, and may, therefore, play a major role in HCV racial disparity. The confirmation that certain genes are deregulated in AA compared to CA tissues also suggests that there is a biological basis for the observed racial disparities.

Background Rapid cooling at procurement after cross-clamping has been the cornerstone of organ preservation. NanoICE is a new form of ice that has emerged in the food industry and is providing more efficient cooling and preservation than regular ice. We hypothesize that the use of NanoICE will accelerate the cooling process of the allograft and will be able to maintain a steady low temperature without causing any significant histologic damage. Methods In this randomized pilot study, 14 pigs were used to study the liver core/surface cooling in a non-survival organ procurement operation. Animals were randomly assigned to 1 of 2 groups, each arm involving 7 pigs: (1) crushed-iced normal saline cooling method (control group) and (2) NanoICE cooling method (study group). Surface and core temperatures were measured with temperature probes, and liver biopsies were obtained before cross-clamping and 15 hours after preservation to assess for any evidence and degree of freezing injury. Results NanoICE was able to reduce and sustain lower core temperatures at 30 minutes, 60 minutes, and 15 hours, compared with crushed ice. The degree of histologic damage (reflecting cold injury) at 15 hours after flushing was not significantly different between the 2 methods. Conclusions NanoICE cools the deeper liver parenchyma more quickly and sustains a cooler temperature than regular crushed ice without causing significantly histologic damage. Future research should focus on whether the effect of NanoICE has any impact on graft function and survival.

While non-alcoholic steatohepatitis is a slowly progressive disease, patients may rarely present in acute liver failure. We describe six patients who developed severe hepatic dysfunction following rapid weight loss or malnutrition. Rapid weight loss (18 to 91 kg) occurred after Roux-en-Y gastric bypass in four patients and starvation-like dieting or hypoalbuminemia was noted in two patients. Four patients either died or received an urgent liver transplant. Pathologic findings were characterized by advanced alcoholic steatohepatitis-like features, including extensive/circumferential centrizonal pericellular fibrosis, central scar with perivenular sclerosis/veno-occlusion with superimposed hepatocellular dropout, abundant/prominent hepatocellular balloons, and numerous Mallory-Denk bodies, but there was no history of excess alcohol consumption. This study characterizes clinicopathologic features of aggressive non-alcoholic steatohepatitis following rapid weight loss or malnutrition, which should be included in the differential diagnosis with alcohol when a patient is considered for liver transplantation. The mechanism of liver injury in aggressive steatohepatitis is unknown, but rapid fat mobilization in obese patients may potentially cause oxidative stress to the liver and further study is needed to determine if there is a genetic predisposition to this form of injury and if antioxidants may protect the liver during rapid weight loss/malnutrition.

We recently reported that cholesterol crystals form in hepatocyte lipid droplets (LDs) in human and experimental nonalcoholic steatohepatitis. Herein, we assigned WT C57BL/6J mice to a high-fat (15%) diet for 6 months, supplemented with 0%, 0.25%, 0.5%, 0.75%, or 1% dietary cholesterol. Increasing dietary cholesterol led to cholesterol loading of the liver, but not of adipose tissue, resulting in fibrosing steatohepatitis at a dietary cholesterol concentration of ≥0.5%, whereas mice on lower-cholesterol diets developed only simple steatosis. Hepatic cholesterol crystals and crown-like structures also developed at a dietary cholesterol concentration ≥0.5%. Crown-like structures consisted of activated Kupffer cells (KCs) staining positive for NLRP3 and activated caspase 1, which surrounded and processed cholesterol crystal-containing remnant LDs of dead hepatocytes. The KCs processed LDs at the center of crown-like structures in the extracellular space by lysosomal enzymes, ultimately transforming into lipid-laden foam cells. When HepG2 cells were exposed to LDL cholesterol, they developed cholesterol crystals in LD membranes, which caused activation of THP1 cells (macrophages) grown in coculture; upregulation of TNF-alpha, NLRP3, and interleukin 1beta (IL1β) mRNA; and secretion of IL-1beta. In conclusion, cholesterol crystals form on the LD membrane of hepatocytes and cause activation and cholesterol loading of KCs that surround and process these LDs by lysosomal enzymes.