Lisa Yerian

In vivo assessment of liver cell apoptosis as a novel biomarker of disease severity in nonalcoholic fatty liver disease

In patients with nonalcoholic fatty liver disease (NAFLD), a liver biopsy remains the only reliable way to differentiate simple steatosis from nonalcoholic steatohepatitis (NASH). Noninvasive methods are urgently needed. Increasing evidence suggests hepatocyte apoptosis is a key mediator of liver injury in NAFLD. The aim of this study was to quantify hepatocyte apoptosis in plasma from patients with NAFLD and correlate it with histological severity. Plasma was obtained from 44 consecutive patients with suspected NAFLD at the time of liver biopsy. Histology was assessed blindly. Caspase‐3–generated cytokeratin‐18 fragments were measured in situ via immunohistochemistry and in vivo using a novel enzyme‐linked immunosorbent assay. Plasma cytokeratin‐18 fragments were markedly increased in patients with NASH compared with patients with simple steatosis or normal biopsies (median [interquartile range]: 765.7 U/L [479.6–991.1], 202.4 U/L [160.4–258.2], 215.5 U/L [150.2–296.2], respectively; P < .001). Cytokeratin‐18 fragment levels independently predicted NASH (OR 1.95; 95% CI 1.18–3.22; P = .009 for every 50 U/L increase). A cutoff value of 395 U/L calculated using the receiver operating characteristic curve approach showed a specificity of 99.9%, a sensitivity of 85.7%, and positive and negative predictive values of 99.9% and 85.7%, respectively, for the diagnosis of NASH. In conclusion, these findings strongly suggest that determination of hepatocyte caspase activation in the blood is a strong and independent predictor of NASH in human subjects. These data highlight the potential usefulness of this test as a noninvasive diagnostic means of determining histological disease severity in patients with NAFLD. (HEPATOLOGY 2006;44:27–33.)

Severe NAFLD with hepatic necroinflammatory changes in mice fed trans fats and a high-fructose corn syrup equivalent

The aims of this study were to determine whether combining features of a western lifestyle in mice with trans fats in a high-fat diet, high-fructose corn syrup in the water, and interventions designed to promote sedentary behavior would cause the hepatic histopathological and metabolic abnormalities that characterize nonalcoholic steatohepatitis (NASH). Male C57BL/6 mice fed ad libitum high-fat chow containing trans fats (partially hydrogenated vegetable oil) and relevant amounts of a high-fructose corn syrup (HFCS) equivalent for 1-16 wk were compared with mice fed standard chow or mice with trans fats or HFCS omitted. Cage racks were removed from western diet mice to promote sedentary behavior. By 16 wk, trans fat-fed mice became obese and developed severe hepatic steatosis with associated necroinflammatory changes. Plasma alanine aminotransferase levels increased, as did liver TNF-alpha and procollagen mRNA, indicating an inflammatory and profibrogenic response to injury. Glucose intolerance and impaired fasting glucose developed within 2 and 4 wk, respectively. Plasma insulin, resistin, and leptin levels increased in a profile similar to that seen in patients with NASH. The individual components of this diet contributed to the phenotype independently; isocaloric replacement of trans fats with lard established that trans fats played a major role in promoting hepatic steatosis and injury, whereas inclusion of HFCS promoted food consumption, obesity, and impaired insulin sensitivity. Combining risk factors for the metabolic syndrome by feeding mice trans fats and HFCS induced histological features of NASH in the context of a metabolic profile similar to patients with this disease. Because dietary trans fats promoted liver steatosis and injury, their role in the epidemic of NASH needs further evaluation.

Consensus Statements for Management of Barrett's Dysplasia and Early-Stage Esophageal Adenocarcinoma, Based on a Delphi Process

BACKGROUND & AIMS Esophageal adenocarcinoma (EA) is increasingly common among patients with Barretts esophagus (BE). We aimed to provide consensus recommendations based on the medical literature that clinicians could use to manage patients with BE and low-grade dysplasia, high-grade dysplasia (HGD), or early-stage EA. METHODS We performed an international, multidisciplinary, systematic, evidence-based review of different management strategies for patients with BE and dysplasia or early-stage EA. We used a Delphi process to develop consensus statements. The results of literature searches were screened using a unique, interactive, Web-based data-sifting platform; we used 11,904 papers to inform the choice of statements selected. An a priori threshold of 80% agreement was used to establish consensus for each statement. RESULTS Eighty-one of the 91 statements achieved consensus despite generally low quality of evidence, including 8 clinical statements: (1) specimens from endoscopic resection are better than biopsies for staging lesions, (2) it is important to carefully map the size of the dysplastic areas, (3) patients that receive ablative or surgical therapy require endoscopic follow-up, (4) high-resolution endoscopy is necessary for accurate diagnosis, (5) endoscopic therapy for HGD is preferred to surveillance, (6) endoscopic therapy for HGD is preferred to surgery, (7) the combination of endoscopic resection and radiofrequency ablation is the most effective therapy, and (8) after endoscopic removal of lesions from patients with HGD, all areas of BE should be ablated. CONCLUSIONS We developed a data-sifting platform and used the Delphi process to create evidence-based consensus statements for the management of patients with BE and early-stage EA. This approach identified important clinical features of the diseases and areas for future studies.

Pentoxifylline improves nonalcoholic steatohepatitis: A randomized placebo‐controlled trial

The primary aim of this study was to compare the effects of pentoxifylline (PTX) versus placebo on the histological features of nonalcoholic steatohepatitis (NASH). In all, 55 adults with biopsy‐confirmed NASH were randomized to receive PTX at a dose of 400 mg three times a day (n = 26) or placebo (n = 29) over 1 year. The primary efficacy endpoint was defined as improvement in histological features of NASH through reduction in steatosis, lobular inflammation, and/or hepatocellular ballooning as reflected by a decrease of ≥2 points in the nonalcoholic fatty liver disease (NAFLD) activity score (NAS). After 1 year, intention‐to‐treat analysis showed a decrease of ≥2 points in the NAS in 38.5% of patients on PTX versus 13.8% of those on placebo (P = 0.036). Per protocol analysis, a decrease of ≥2 points in the NAS from baseline was observed in 50% of the patients on PTX versus 15.4% of those on placebo (P = 0.01). The mean change in NAS score from baseline was −1.6 in the PTX group, versus −0.1 in the placebo group (P < 0.001). PTX significantly improved steatosis (mean change in score −0.9 versus −0.04 with placebo, P < 0.001) and lobular inflammation (median change −1 versus 0 with placebo, P = 0.02). No significant effects in hepatocellular ballooning were observed. PTX also improved liver fibrosis (mean change in fibrosis score was −0.2 among those on PTX versus +0.4 among those on placebo, P = 0.038). Although not statistically significant (P = 0.17), improvement in fibrosis was observed in a greater proportion (35%) of patients in the PTX group compared to placebo (15%). Adverse effects were similar in both groups. Conclusion: PTX improved histological features of NASH compared to placebo. PTX was well tolerated in patients with NASH (ClinicalTrials.gov number NCT00590161). (HEPATOLOGY 2011)

Local expression of B7-H1 promotes organ-specific autoimmunity and transplant rejection

A number of studies have suggested B7-H1, a B7 family member, inhibits T cell responses. Therefore, its expression on nonlymphoid tissues has been proposed to prevent T cell-mediated tissue destruction. To test this hypothesis, we generated transgenic mice that expressed B7-H1 on pancreatic islet beta cells. Surprisingly, we observed accelerated rejection of transplanted allogeneic B7-H1-expressing islet beta cells. Furthermore, transgenic B7-H1 expression broke immune tolerance, as some of the mice spontaneously developed T cell-dependent autoimmune diabetes. In addition, B7-H1 expression increased CD8+ T cell proliferation and promoted autoimmunity induction in a T cell adoptive transfer model of diabetes. Consistent with these findings, B7-H1.Ig fusion protein augmented naive T cell priming both in vitro and in vivo. Our results demonstrate that B7-H1 can provide positive costimulation for naive T cells to promote allograft rejection and autoimmune disease pathogenesis.

Risk Factors for Progression of Low-Grade Dysplasia in Patients With Barrett's Esophagus

BACKGROUND & AIMS Data vary on the progression of low-grade dysplasia (LGD) in patients with Barretts esophagus (BE); in patients with LGD, we investigated the incidence of high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) and compared progression in patients with different forms of LGD (prevalent vs incident and multifocal vs unifocal). We assessed the effects of consensus diagnosis of LGD on progression rates to HGD and EAC among expert pathologists. METHODS In a multicenter outcomes project, 210 patients with BE and LGD (classified as incident, prevalent, or persistent) were included. Patients were followed up for an average of 6.2 years (959.6 patient-years). Persistent LGD was defined as detection of LGD on ≥2 consecutive occasions during the follow-up period and extent as either unifocal (LGD at one level of BE segment) or multifocal (>1 level). Histology specimens were reviewed by 2 blinded pathologists. RESULTS Six patients developed EAC (incidence of 0.44%/year), and 21 developed HGD (incidence of 1.6%/year). The incidence of the combination of HGD and EAC was 1.83%/year. There were no associations between presence of prevalent, incident, or persistent LGD and the extent of LGD with progression rates. Based on consensus diagnosis of 88 reviewed specimens, there was no difference in the progression of LGD to either EAC (the incidence based on analyses by the local pathologist was 0.18%/year, the incidence when there was agreement between the local and one central pathologist was 0.21%/year, and the incidence when all 3 pathologists were in agreement was 0.39%/year) or combined HGD and EAC (0.94%/year, 0.87%/year, and 0.84%/year, respectively). CONCLUSIONS Overall, patients with BE and LGD have a low annual incidence of EAC, similar to nondysplastic BE. There are no risk factors for progression and there is significant interobserver variation in diagnosis, even among expert pathologists.

Nonalcoholic Steatohepatitis in Children: A Multicenter Clinicopathological Study

Nonalcoholic fatty liver disease (NAFLD) may have distinct histological features in children and adults, but to date limited data are available on the spectrum and significance of histological lesions in pediatric patients. We conducted a multicenter study of children with well‐characterized, biopsy‐proven NAFLD to (1) assess the presence and significance of a constellation of histological lesions and (2) identify clinical and laboratory predictors of disease severity. One hundred thirty children with NAFLD seen from 1995 to 2007 in five centers in the United States and Canada were studied. Clinical and laboratory data were collected. Slides stained with hematoxylin‐eosin and trichrome were evaluated by two liver pathologists. The NAFLD activity score (NAS) and the pattern of liver injury (type 1 or adult versus type 2 or pediatric nonalcoholic steatohepatitis [NASH]) were recorded. Fibrosis was staged using a published 7‐point scale. The median age was 12 years (range, 4‐18 years); 63% were boys, and 52% were Caucasian. Fibrosis was present in 87% of patients; of these, stage 3 (bridging fibrosis) was present in 20%. No patient had cirrhosis. The median NAS was 4. Overlapping features of both type 1 (adult pattern) and type 2 (pediatric pattern) NASH were found in 82% of patients. Compared with patients with no or mild fibrosis, those with significant fibrosis were more likely to have higher lobular and portal inflammation scores (P < 0.01), perisinusoidal fibrosis (P < 0.001), and NAS ≥5 (P < 0.005). Serum aspartate aminotransferase levels were the only clinical or laboratory data that independently predicted severity of fibrosis (P = 0.003). Conclusion: Our results highlight the limitations of published proposals to classify pediatric NAFLD, and identified histological lesions associated with progressive disease. (HEPATOLOGY 2009.)

Mass spectrometric profiling of oxidized lipid products in human nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

Oxidative stress is a core abnormality responsible for disease progression in nonalcoholic fatty liver disease (NAFLD). However, the pathways that contribute to oxidative damage in vivo are poorly understood. Our aims were to define the circulating profile of lipid oxidation products in NAFLD patients, the source of these products, and assess whether their circulating levels reflect histological changes in the liver. The levels of multiple structurally specific oxidized fatty acids, including individual hydroxy-eicosatetraenoic acids (HETE), hydroxy-octadecadenoic acids (HODE), and oxo-octadecadenoic acids (oxoODE), were measured by mass spectrometry in plasma at time of liver biopsy in an initial cohort of 73 and a validation cohort of 49 consecutive patients. Of the markers monitored, 9- and 13-HODEs and 9- and 13-oxoODEs, products of free radical-mediated oxidation of linoleic acid (LA), were significantly elevated in patients with nonalcoholic steatohepatitis (NASH), compared with patients with steatosis. A strong correlation was revealed between these oxidation products and liver histopathology (inflammation, fibrosis, and steatosis). Further analyses of HODEs showed equivalent R and S chiral distribution. A risk score for NASH (oxNASH) was developed in the initial clinical cohort and shown to have high diagnostic accuracy for NASH versus steatosis in the independent validation cohort. Subjects with elevated oxNASH levels (top tertile) were 9.7-fold (P < 0.0001) more likely to have NASH than those with low levels (bottom tertile). Collectively, these findings support a key role for free radical-mediated linoleic acid oxidation in human NASH and define a risk score, oxNASH, for noninvasive detection of the presence of NASH.

Neutrophil to lymphocyte ratio: a new marker for predicting steatohepatitis and fibrosis in patients with nonalcoholic fatty liver disease.

Nonalcoholic steatohepatitis (NASH), the most severe form of nonalcoholic fatty liver disease (NAFLD), is associated with inflammation and increased oxidative stress. The neutrophil/lymphocyte ratio (N/L) integrates information on the inflammatory milieu and physiological stress.

Poor Interobserver Agreement in the Distinction of High-Grade Dysplasia and Adenocarcinoma in Pretreatment Barrett's Esophagus Biopsies

OBJECTIVE:Grading Barretts dysplasia at the lower end of the metaplasia-dysplasia spectrum (negative, indefinite, and low-grade dysplasia) suffers from poor interobserver agreement, even among gastrointestinal pathologists. Data evaluating interobserver agreement in Barretts mucosal biopsies with changes at the upper end of the dysplasia spectrum (high-grade dysplasia, intramucosal, and submucosal adenocarcinoma) have not been published. The accurate categorization of pretreatment biopsies drives therapeutic decision making, but if the diagnostic distinction between cancer and high-grade dysplasia in Barretts biopsies is inconsistent, then the use of these diagnoses to make management decisions is suspect. To this end, our aim was to assess interobserver reproducibility among a group of gastrointestinal pathologists in the interpretation of preresection biopsies.METHODS:All study pathologists agreed upon the histologic criteria distinguishing four diagnostic categories, including high-grade dysplasia; high-grade dysplasia with marked distortion of glandular architecture, cannot exclude intramucosal adenocarcinoma; intramucosal adenocarcinoma; and submucosally invasive adenocarcinoma. The histologic criteria were used to independently review preresection biopsies from 163 consecutive Barretts esophagus patients with at least high-grade dysplasia who ultimately underwent esophagectomy. Reviewers recorded the specific histologic criteria used to categorize each case and Kappa statistics were calculated to assess interobserver agreement.RESULTS:Using kappa statistics, the overall agreement was only fair (κ= 0.30). Agreement for high-grade dysplasia was moderate (κ= 0.47), while agreement for high-grade dysplasia with marked architectural distortion, cannot exclude intramucosal adenocarcinoma and intramucosal adenocarcinoma were only fair (κ= 0.21 and 0.30, respectively) and agreement for submucosal adenocarcinoma was poor (κ= 0.14).CONCLUSIONS:The overall poor interobserver reproducibility among gastrointestinal pathologists who see a high volume of Barretts cases calls into question treatment regimens based on the assumption that high-grade dysplasia, intramucosal adenocarcinoma, and submucosal adenocarcinoma can reliably be distinguished in biopsy specimens.