Indeterminate etiology of acute liver failure in North America: Less common, still grave prognosis.

BACKGROUND: The etiology of acute liver failure (ALF) remains one of the most important factors in determining prognosis and predicting outcomes. In a significant proportion of ALF cases, however, the etiology remains unknown and is categorized as indeterminate ALF (IND-ALF). In this study, we summarize findings from patients with IND-ALF from 32 transplant centers across the United States, and we compare laboratory, prognostic, and outcome data for patients with IND-ALF. METHODS: Between 1998 and 2019, 3364 adult patients with ALF or acute liver injury (ALI) from 32 liver transplant centers were enrolled in the ALFSG registry. The primary clinical outcome of interest was 21-day transplant-free survival (TFS). RESULTS: Of the 3364 patients enrolled in the ALFSG registry, 3.4 % (n = 114) were adjudicated as true indeterminate. On multivariate analysis, patients with a lower bilirubin, lower INR, lack of use of mechanical ventilation and no clinical features of coma at baseline had a higher odds ratio of transplant free survival. The number of deaths were similar between patients with true-IND ALF versus patients with indeterminable ALF (29.8% vs. 27.2%), with almost half of the patients requiring liver transplant (42.1% vs. 45.7%). CONCLUSION: We illustrate the poor prognoses that true-IND-ALF and indeterminable ALF carry and the need for emergency liver transplantation in most cases.

Autoimmune hepatitis presenting as acute liver failure: A 20-year retrospective review of North America.

Autoimmune hepatitis is a common cause of acute liver failure. Treatment includes steroids for acute liver injury and liver transplantation in those who fail to respond or develop acute liver failure. The aim of this study is to further characterize acute liver failure secondary to autoimmune hepatitis and identify variables that predict 21-day transplant-free survival. This study included adults hospitalized with acute liver failure enrolled in the Acute Liver Failure Study Group Registry between 1998 and 2019 from 32 centers within the US. The etiology of all cases was reviewed by the Adjudication Committee, and all cases identified as autoimmune hepatitis were included. Acute liver injury was defined as an INR ≥2.0 without encephalopathy and acute liver failure as INR ≥ 1.5 with encephalopathy. Laboratory and clinical data were reviewed. Variables significantly associated with 21-day transplant-free survival were used to develop a multivariable logistic regression model.  A total of 193 cases of acute liver failure secondary to autoimmune hepatitis were identified and reviewed. There were 161 patients (83.4%) diagnosed with acute liver failure on enrollment, and 32 (16.6%) developed acute liver failure during hospitalization. At 21 days, 115 (59.6%) underwent liver transplantation, 28 (14.5%) had transplant-free survival, and 46 (23.8%) died before liver transplantation. Higher admission values of bilirubin, INR, and coma grade were associated with worse outcomes. A prognostic index incorporating bilirubin, INR, coma grade, and platelet count had a concordance statistic of 0.84. Acute liver failure secondary to autoimmune hepatitis is associated with a high short-term mortality. We developed a model specifically for autoimmune hepatitis that may be helpful in predicting 21-day transplant-free survival and early identification of patients in need of expedited liver transplant evaluation.

Preliminary observations on the movement ecology of a crested horn shark (Heterodontus galeatus).

The residency and movements of a single acoustically tagged female crested horn shark (Heterodontus galeatus) were monitored in Jervis Bay, Australia. The individual was intermittently detected by receivers throughout the 8-year study period and showed preference for particular rocky reefs in terms of its residency indices and duration of residency events. This individual exhibited lower residency and dissimilar movement patterns to that of the well-studied and sympatric Port Jackson shark (Heterodontus portusjacksoni), highlighting the need for research into the basic life history and movement ecology of H. galeatus.

A Brief History of Hepatic Encephalopathy.

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Residency and movement patterns of adult Port Jackson sharks (Heterodontus portusjacksoni) at a breeding aggregation site.

Examining the movement ecology of mesopredators is fundamental to developing an understanding of their biology, ecology and behaviour, as well as the communities and ecosystems they influence. The limited research on the residency and movements of benthic marine mesopredators has primarily used visual tags, which do not allow for the efficient and accurate monitoring of individual space use. In this study, the authors investigated the residency and movement patterns of Port Jackson sharks Heterodontus portusjacksoni (Meyer 1793) at a breeding aggregation site in Jervis Bay, south-eastern Australia, using passive acoustic telemetry to further our understanding of the movement ecology of these important mesopredators. Between 2012 and 2014, individuals were tagged with acoustic transmitters, and their residency and movements within the bay were monitored for up to 4 years. H. portusjacksoni showed strong preferences for particular reefs within and between breeding seasons. Males had significantly higher residency indices at their favoured sites relative to females, suggesting that males may be engaging in territorial behaviour. Conversely, female H. portusjacksoni exhibited higher roaming indices relative to males indicating that females may move between sites to assess males. Finally, H. portusjacksoni showed temporal variation in movements between reefs with individuals typically visiting more reefs at night relative to the day, dusk and dawn corresponding with their nocturnal habits.

Testosterone is Associated With Nonalcoholic Steatohepatitis and Fibrosis in Premenopausal Women With NAFLD.

BACKGROUND & AIMS: Higher testosterone contributes to imaging-confirmed nonalcoholic fatty liver disease (NAFLD) in women, but whether testosterone influences their disease severity is unknown. METHODS: The association of free testosterone (free T) with nonalcoholic steatohepatitis (NASH) was determined in pre-menopausal women with biopsy-confirmed NAFLD (n = 207). Interaction testing was performed for age and free T given decline in testosterone with age, and association of aging with NASH. Regression models adjusted for abdominal adiposity, diabetes, and dyslipidemia. RESULTS: Median age was 35 yrs (interquartile range, 29-41); 73% were white, 25% Hispanic; 32% had diabetes, 93% abdominal adiposity, and 95% dyslipidemia. 69% had NASH, 67% any fibrosis, and 15% advanced fibrosis. Higher free T levels were associated with NAFLD severity in younger women (interaction P value <.02). In the youngest age quartile, free T was independently associated with NASH (odds ratio [OR], 2.3; 95% CI, 1.2-4.4), NASH fibrosis (OR, 2.1; 95% CI, 1.1-3.8), and higher fibrosis stage (OR, 1.9; 95% CI, 1.1-3.4), P value .02. In these women, the proportion with NASH steadily rose from 27% to 88%, and with NASH fibrosis rose from 27% to 81%, with higher free T quartiles (P < .01). Free T was additionally associated with abdominal adiposity among all pre-menopausal women (OR, 2.2; 95% CI, 1.2-4.1: P = .02). CONCLUSIONS: In young women with NAFLD, higher testosterone levels conferred a 2-fold higher risk of NASH and NASH fibrosis, and increased risk of abdominal adiposity, supporting a potential mechanistic link of abdominal fat on testosterone-associated liver injury. Testosterone may represent an early risk factor for NASH progression in young women, prior to their onset of more dominant, age-related metabolic risk factors.

Acute Liver Failure of Indeterminate Etiology: A Comprehensive Systematic Approach by An Expert Committee to Establish Causality.

OBJECTIVES: In the United States, the Acute Liver Failure Study Group (ALFSG) registry lists approximately 11% of cases as of indeterminate etiology (IND-ALF) as determined by the respective local site principal investigator (PI). Traditionally, IND-ALF has prompted concern that other viruses or toxins might be implicated. We hypothesized that many IND- ALF cases would have an identifiable etiology upon further investigation. Improving the identification process should reduce the number of truly indeterminate cases. METHODS: Specific definitions for each etiology ("etiology-specific algorithms") were developed by a Causality Adjudication Committee that included six reviewers (each with 20 or more years of experience). Of 2718 patients with ALF, 303 initially deemed IND-ALF by site PIs underwent committee review guided by the algorithms. Acetaminophen (APAP) protein adducts were measured in sera when available, additional HEV testing was performed, and viral sequences sought by microarray analysis and metagenomic next-generation sequencing (mNGS). Study sites were asked to provide liver biopsy and/or explant reports and to update serological findings not reported previously. RESULTS: Nearly half (142, 46.9%) of the 303 IND-ALF cases could be reassigned to a single, defined etiology and rated as highly likely or probable; 11 additional cases, upon review, did not meet ALF criteria. Amongst reassigned etiologies, 45 were previously unrecognized APAP, 34 autoimmune hepatitis (AIH), 24 drug-induced liver injury (DILI), 13 various viral causes, 12 ischemia, and 14 miscellaneous other etiologies. The remaining 150, deemed true IND-ALF, represented just 5.5%. CONCLUSIONS: The indeterminate etiology in ALF includes patients with a diagnosis that is discernible after closer examination. Revision of etiologic diagnoses of indeterminate cases using added testing and expert opinion is useful in understanding all aspects of ALF.

Association Between Cytokines and Liver Histology in Children with Nonalcoholic Fatty Liver Disease.

BACKGROUND: Reliable non-invasive markers to characterize inflammation, hepatocellular ballooning, and fibrosis in nonalcoholic fatty liver disease (NAFLD) are lacking. We investigated the relationship between plasma cytokine levels and features of NAFLD histology to gain insight into cellular pathways driving NASH and to identify potential non-invasive discriminators of NAFLD severity and pattern. METHODS: Cytokines were measured from plasma obtained at enrollment in pediatric participants in NASH Clinical Research Network studies with liver biopsy-proven NAFLD. Cytokines were chosen a priori as possible discriminators of NASH and its components. Minimization of Akaike Information Criterion (AIC) was used to determine cytokines retained in multivariable models. RESULTS: Of 235 subjects, 31% had "Definite NASH" on liver histology, 43% had "Borderline NASH", and 25% had NAFLD but not NASH. Total plasminogen activator inhibitor 1 (PAI1) and activated PAI1 levels were higher in pediatric participants with Definite NASH and with lobular inflammation. Interleukin-8 (IL-8) was higher in those with stage 3-4 fibrosis and lobular inflammation. sIL-2rα was higher in children with stage 3-4 fibrosis and portal inflammation. In multivariable analysis, PAI1 variables were discriminators of Borderline/Definite NASH, definite NASH, lobular inflammation and ballooning. IL-8 increased with steatosis and fibrosis severity; sIL-2rα increased with fibrosis severity and portal inflammation. IL-7 decreased with portal inflammation and fibrosis severity. CONCLUSIONS: Plasma cytokines associated with histology varied considerably among NASH features, suggesting promising avenues for investigation. Future, more targeted analysis is needed to identify the role of these markers in NAFLD and to evaluate their potential as non-invasive discriminators of disease severity.

Does detection range matter for inferring social networks in a benthic shark using acoustic telemetry?

Accurately estimating contacts between animals can be critical in ecological studies such as examining social structure, predator-prey interactions or transmission of information and disease. While biotelemetry has been used successfully for such studies in terrestrial systems, it is still under development in the aquatic environment. Acoustic telemetry represents an attractive tool to investigate spatio-temporal behaviour of marine fish and has recently been suggested for monitoring underwater animal interactions. To evaluate the effectiveness of acoustic telemetry in recording interindividual contacts, we compared co-occurrence matrices deduced from three types of acoustic receivers varying in detection range in a benthic shark species. Our results demonstrate that (i) associations produced by acoustic receivers with a large detection range (i.e. Vemco VR2W) were significantly different from those produced by receivers with smaller ranges (i.e. Sonotronics miniSUR receivers and proximity loggers) and (ii) the position of individuals within their network, or centrality, also differed. These findings suggest that acoustic receivers with a large detection range may not be the best option to represent true social networks in the case of a benthic marine animal. While acoustic receivers are increasingly used by marine ecologists, we recommend users first evaluate the influence of detection range to depict accurate individual interactions before using these receivers for social or predator-prey studies. We also advocate for combining multiple receiver types depending on the ecological question being asked and the development of multi-sensor tags or testing of new automated proximity loggers, such as the Encounternet system, to improve the precision and accuracy of social and predator-prey interaction studies.

Novel plasma biomarkers associated with liver disease severity in adults with nonalcoholic fatty liver disease.

Despite the high prevalence of nonalcoholic fatty liver disease (NAFLD), therapeutic options and noninvasive markers of disease activity and severity remain limited. We investigated the association between plasma biomarkers and liver histology in order to identify markers of disease activity and severity in patients with biopsy-proven NAFLD. Thirty-two plasma biomarkers chosen a priori as possible discriminators of NAFLD were measured in participants enrolled in the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network. Dichotomized histologic outcomes were evaluated using centrally read biopsies. Biomarkers with statistically significant associations with NAFLD histology were evaluated in multivariable models adjusted for clinical factors. Of 648 participants (74.4% white, 61.7% female, mean age 47.7 years), 58.0% had definite NASH, 55.5% had mild/no fibrosis (stage 0-1), and 44.4% had significant fibrosis (stage 2-4). Increased activated plasminogen activator inhibitor 1 had a strong association with definite NASH compared to not NASH or borderline NASH in multivariable analysis (odds ratio = 1.20, 95% confidence interval 1.08-1.34, P < 0.001). Biomarkers associated with significant fibrosis (versus mild/no fibrosis) in multivariable analysis included higher levels of interleukin-8, monocyte chemoattractant protein-1, resistin, soluble interleukin-1 receptor I, soluble interleukin-2 receptor alpha, and tumor necrosis factor alpha and lower levels of insulin-like growth factor 2. CONCLUSIONS: Specific plasma biomarkers are significantly associated with disease activity and severity of fibrosis in NAFLD and are potentially valuable tools for noninvasive stratification of patients with NAFLD and identification of targets for therapeutic intervention. (Hepatology 2017;65:65-77).

Coffee consumption in NAFLD patients with lower insulin resistance is associated with lower risk of severe fibrosis.

BACKGROUND & AIMS: Coffee has inverse relationships with both type 2 diabetes and hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). Relationships were explored between coffee intake and insulin resistance (IR) with respect to NAFLD histologic severity. METHODS: We analyzed data from 782 adults (≥18 years) in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) from 2004 to 2008. IR was assessed using the HOMA-IR. We modeled associations between coffee intake and NAFLD histologic severity using multiple logistic regression; and interactions between coffee and IR on NAFLD histology were explored. RESULTS: Among 782 participants, 38% (n = 295) were men, 12% (n = 97) were Latino, mean age (± standard deviation) was 48 ± 12 years. Median BMI was 33.5 kg/m(2) [interquartile range, 29.7-38.3] and median HOMA-IR was 4.3 [2.7-7.2]. Diabetes was present in 24% (n = 189). NASH was present in 79% (n = 616), and 25% (n = 199) had advanced fibrosis. The frequency of coffee intake (cups/day, cpd) was as follows: 0 cpd, n = 230 (29%); <1 cpd, n = 219 (28%); 1 to <2 cpd, n = 116 (15%); ≥2 cpd, n = 217 (28%). The effect of coffee on fibrosis varied with degree of IR (interaction P = 0.001). Coffee consumers with less IR, defined as HOMA-IR<4.3, had a lower odds of advanced fibrosis [OR = 0.64; 95% CI, (0.46-0.88), P = 0.001]. There was no protective effect of coffee on advanced fibrosis among individuals with higher HOMA-IR [OR = 1.06, 95% CI (0.87-1.28), P = 0.6]. CONCLUSIONS: Coffee intake is inversely associated with advanced fibrosis among NAFLD patients with lower HOMA-IR. Our findings warrant further investigation given the worldwide ubiquity of coffee intake.

Rifaximin is safe and well tolerated for long-term maintenance of remission from overt hepatic encephalopathy.

BACKGROUND & AIMS: Rifaximin is a gut-selective, oral antimicrobial agent shown to reduce the recurrence of overt hepatic encephalopathy (HE) and HE-related hospitalizations in a 6-month, randomized, controlled trial (RCT). We performed a phase 3, open-label maintenance study to assess the safety and rate of hospitalization with long-term rifaximin use. METHODS: We conducted a 24-month, open-label maintenance study of rifaximin (550 mg, twice daily) in patients with HE who participated in the previous RCT of rifaximin or new patients enrolled from March 2007 to December 2010. Safety was assessed (adverse events, clinical laboratory parameters) for the integrated population of all patients, who were given rifaximin 550 mg twice daily (all-rifaximin population, N = 392). Safety and hospitalization data were compared between the group given placebo in the original RCT (n = 159) and those given rifaximin (n = 140). RESULTS: In the all-rifaximin population, the median exposure to rifaximin was 427.0 days (range, 2-1427 d), with 510.5 person-years of exposure. The profile and rate of adverse events with long-term rifaximin treatment were similar to those of the original RCT. There was no increase in the rate of infections, including with Clostridium difficile, or development of bacterial antibiotic resistance. Rates of hospitalizations with long-term rifaximin administration remained low: the HE-related hospitalization rate, normalized for exposure (0.21; all-rifaximin population), was similar to that of the rifaximin group in the original RCT (0.30), and lower than that for the placebo group (0.72). CONCLUSIONS: Long-term treatment (≥24 mo) with rifaximin (550 mg, twice daily) appears to provide a continued reduction in the rate of HE-related and all-cause hospitalization, without an increased rate of adverse events. ClinicalTrials.gov number: NCT00686920.

Randomized, double-blind, controlled study of glycerol phenylbutyrate in hepatic encephalopathy.

UNLABELLED: Glycerol phenylbutyrate (GPB) lowers ammonia by providing an alternate pathway to urea for waste nitrogen excretion in the form of phenylacetyl glutamine, which is excreted in urine. This randomized, double-blind, placebo-controlled phase II trial enrolled 178 patients with cirrhosis, including 59 already taking rifaximin, who had experienced two or more hepatic encephalopathy (HE) events in the previous 6 months. The primary endpoint was the proportion of patients with HE events. Other endpoints included the time to first event, total number of events, HE hospitalizations, symptomatic days, and safety. GPB, at 6 mL orally twice-daily, significantly reduced the proportion of patients who experienced an HE event (21% versus 36%; P=0.02), time to first event (hazard ratio [HR]=0.56; P<0.05), as well as total events (35 versus 57; P=0.04), and was associated with fewer HE hospitalizations (13 versus 25; P=0.06). Among patients not on rifaximin at enrollment, GPB reduced the proportion of patients with an HE event (10% versus 32%; P<0.01), time to first event (HR=0.29; P<0.01), and total events (7 versus 31; P<0.01). Plasma ammonia was significantly lower in patients on GPB and correlated with HE events when measured either at baseline or during the study. A similar proportion of patients in the GPB (79%) and placebo groups (76%) experienced adverse events. CONCLUSION: GPB reduced HE events as well as ammonia in patients with cirrhosis and HE and its safety profile was similar to placebo. The findings implicate ammonia in the pathogenesis of HE and suggest that GPB has therapeutic potential in this population. (Clinicaltrials.gov, NCT00999167).

Association between diabetes, family history of diabetes, and risk of nonalcoholic steatohepatitis and fibrosis.

UNLABELLED: Previous studies have shown familial aggregation of insulin resistance and nonalcoholic fatty liver disease (NAFLD). Therefore, we aimed to examine whether family history of diabetes mellitus (DM) is associated with nonalcoholic steatohepatitis (NASH) and fibrosis in patients with NAFLD. This was a cross-sectional analysis in participants of the NAFLD Database study and PIVENS trial who had available data on family history of DM. One thousand and sixty-nine patients (63% women), with mean age of 49.6 (± 11.8) years and body mass index (BMI) of 34.2 (± 6.4) kg/m(2) , were included. Thirty percent had DM, and 56% had a family history of DM. Both personal history of DM and family history of DM were significantly associated with NASH, with an odds ratio (OR) of 1.93 (95% confidence interval [CI]: 1.37-2.73; P <0.001) and 1.48 (95% CI: 1.11-1.97; P = 0.01) and any fibrosis with an OR of 3.31 (95% CI: 2.26-4.85; P < 0.001) and 1.66 (95% CI: 1.25-2.20; P < 0.001), respectively. When the models were adjusted for age, sex, BMI, ethnicity, and metabolic traits, the association between diabetes and family history of DM with NASH showed an increased adjusted OR of 1.76 (95% CI: 1.13-2.72; P < 0.001) and 1.34 (95% CI: 0.99-1.81; P = 0.06), respectively, and with any fibrosis with a significant adjusted OR of 2.57 (95% CI: 1.61-4.11; P < 0.0001) and 1.38 (95% CI: 1.02-1.87; P = 0.04), respectively. After excluding patients with personal history of diabetes, family history of DM was significantly associated with the presence of NASH and any fibrosis with an adjusted OR of 1.51 (95% CI: 1.01-2.25; P = 0.04) and 1.49 (95% CI: 1.01-2.20; P = 0.04), respectively. CONCLUSIONS: Diabetes is strongly associated with risk of NASH, fibrosis, and advanced fibrosis. Family history of diabetes, especially among nondiabetics, is associated with NASH and fibrosis in NAFLD.

Relationship between adipose tissue insulin resistance and liver histology in nonalcoholic steatohepatitis: a pioglitazone versus vitamin E versus placebo for the treatment of nondiabetic patients with nonalcoholic steatohepatitis trial follow-up study.

UNLABELLED: The PIVENS (Pioglitazone versus Vitamin E versus Placebo for the Treatment of Nondiabetic Patients with Nonalcoholic Steatohepatitis [NASH]) trial demonstrated that pioglitazone and vitamin E improved liver histology to varying degrees, but the mechanisms are unknown. We conducted a study to examine the changes in adipose tissue insulin resistance (Adipo-IR) during the PIVENS trial and its relationship to histological endpoints. Adipo-IR (fasting nonesterified fatty acids [NEFAs] × fasting insulin) was calculated at baseline and after 16 and 96 weeks of therapy. Compared to placebo, the baseline Adipo-IR was not different in either the vitamin E group (P = 0.34) or the pioglitazone group (P = 0.29). Baseline Adipo-IR was significantly associated with fibrosis score (P = 0.02), but not with other histological features or nonalcoholic fatty liver disease (NAFLD) activity score (NAS). After 16 weeks, compared to placebo, the pioglitazone group had a significant reduction in Adipo-IR (-15.7 versus -1.91; P = 0.02), but this effect did not persist at 96 weeks (-3.25 versus -4.28; P = 0.31). Compared to placebo, Adipo-IR in the vitamin E group did not change significantly either after 16 weeks (P = 0.70) or after 96 weeks (P = 0.85). Change in Adipo-IR at week 16 was not associated with changes in any histological parameters at week 96, but improvement in Adipo-IR at week 96 was significantly associated with improvement in ballooning (P = 0.03), fibrosis (P = 0.004), and NAS (P = 0.01). CONCLUSION: Vitamin E improved liver histology independent of changes in Adipo-IR, and pioglitazone treatment acutely improved Adipo-IR, but this was not sustained. Changes in Adipo-IR were associated with changes in liver histology, including fibrosis.

Ethnicity and nonalcoholic fatty liver disease.

UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disorder in the United States; however, few data are available about racial and ethnic variation. We investigated relationships between ethnicity, NAFLD severity, metabolic derangements, and sociodemographic characteristics in a well-characterized cohort of adults with biopsy-proven NAFLD. Data were analyzed from 1,026 adults (≥18 years) in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) from 2004 to 2008, for whom liver histology data were available within 6 months of enrollment. Associations between ethnicity (i.e., Latino versus non-Latino white) and NAFLD severity (i.e., NASH versus non-NASH histology and mild versus advanced fibrosis) were explored with multiple logistic regression analysis. We also investigated effect modification of ethnicity on metabolic derangements for NAFLD severity. Within the NASH CRN, 77% (N = 785) were non-Latino white and 12% (N = 118) were Latino. Sixty-one percent (N = 628) had NASH histology and 28% (N = 291) had advanced fibrosis. Latinos with NASH were younger, performed less physical activity, and had higher carbohydrate intake, compared to non-Latino whites with NASH. Gender, diabetes, hypertension, hypertriglyceridemia, aspartate aminotransferase (AST), platelets, and the homeostasis model assessment of insulin resistance (HOMA-IR) were significantly associated with NASH. Age, gender, AST, alanine aminotransferase, alkaline phosphatase, platelets, total cholesterol, hypertension, and HOMA-IR, but not ethnicity, were significantly associated with advanced fibrosis. The effect of HOMA-IR on the risk of NASH was modified by ethnicity: HOMA-IR was not a significant risk factor for NASH among Latinos (odds ratio [OR] = 0.93; 95% confidence interval [CI]: 0.85-1.02), but was significant among non-Latino whites (OR, 1.06; 95% CI: 1.01-1.11). CONCLUSION: Metabolic risk factors and sociodemographic characteristics associated with NASH differ by ethnicity. Additional insights into NASH pathogenesis may come from further studies focused on understanding ethnic differences in this disease.

Centrizonal arteries and microvessels in nonalcoholic steatohepatitis.

Correct classification of nonalcoholic steatohepatitis (NASH) liver biopsies is of critical importance and relies on correct orientation to microscopic liver architecture. Centrizonal arteries can cause central zones to be mistaken for portal tracts, especially in the setting of centrizonal ductular reaction, and result in either missed diagnosis or inaccurate staging of NASH. A total of 100 randomly selected biopsies from NASH Clinical Research Network participants (February 2005 to August 2006, fibrosis stage >1a) were evaluated for arteries and CD34-positive microvessels in the centrizonal region. Prevalence of both centrizonal arteries and CD34-positive microvessels was graded as 0 (none in central zones), 1 (1 to 2 central zones with vessels), 2 (<50% of central zones with vessels), or 3 (≥50% of central zones with vessels). Centrizonal arteries and CD34-positive microvessels were present in 40 and 100 cases (40% and 100%), respectively. Arteries and CD34-positive microvessels were more commonly found in central zones in biopsies with greater degrees of fibrosis (62% with arteries in stage 3 to 4 versus 21% in stage 1 to 2 and 70% with microvessels in stage 3 to 4 versus 25% in stage 1 to 2), with increased prevalence of both centrizonal arteries and CD34-positive microvessels correlating directly with fibrosis stage (P<0.001). Ductular reaction was a common finding (55%) in patients with central zone arteries. The presence of centrizonal arteries must be recognized to allow for correct orientation to liver architecture in NASH and, together with the finding of increased CD34-positive microvessel formation in higher-stage fibrosis, suggests a possible association between neoangiogenesis and NASH progression to cirrhosis.