Cynthia Behling

Design and validation of a histological scoring system for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis in the absence of a history of significant alcohol use or other known liver disease. Nonalcoholic steatohepatitis (NASH) is the progressive form of NAFLD. The Pathology Committee of the NASH Clinical Research Network designed and validated a histological feature scoring system that addresses the full spectrum of lesions of NAFLD and proposed a NAFLD activity score (NAS) for use in clinical trials. The scoring system comprised 14 histological features, 4 of which were evaluated semi‐quantitatively: steatosis (0‐3), lobular inflammation (0‐2), hepatocellular ballooning (0‐2), and fibrosis (0‐4). Another nine features were recorded as present or absent. An anonymized study set of 50 cases (32 from adult hepatology services, 18 from pediatric hepatology services) was assembled, coded, and circulated. For the validation study, agreement on scoring and a diagnostic categorization (“NASH,” “borderline,” or “not NASH”) were evaluated by using weighted kappa statistics. Inter‐rater agreement on adult cases was: 0.84 for fibrosis, 0.79 for steatosis, 0.56 for injury, and 0.45 for lobular inflammation. Agreement on diagnostic category was 0.61. Using multiple logistic regression, five features were independently associated with the diagnosis of NASH in adult biopsies: steatosis (P = .009), hepatocellular ballooning (P = .0001), lobular inflammation (P = .0001), fibrosis (P = .0001), and the absence of lipogranulomas (P = .001). The proposed NAS is the unweighted sum of steatosis, lobular inflammation, and hepatocellular ballooning scores. In conclusion, we present a strong scoring system and NAS for NAFLD and NASH with reasonable inter‐rater reproducibility that should be useful for studies of both adults and children with any degree of NAFLD. NAS of ≥5 correlated with a diagnosis of NASH, and biopsies with scores of less than 3 were diagnosed as “not NASH.” (HEPATOLOGY 2005;41:1313–1321.)

Prevalence of fatty liver in children and adolescents.

OBJECTIVE. Fatty liver disease is diagnosed increasingly in children, but the prevalence remains unknown. We sought to determine the prevalence of pediatric fatty liver as diagnosed by histology in a population-based sample. METHODS. We conducted a retrospective review of 742 children between the ages of 2 and 19 years who had an autopsy performed by a county medical examiner from 1993 to 2003. Fatty liver was defined as ≥5% of hepatocytes containing macrovesicular fat. RESULTS. Fatty liver was present in 13% of subjects. For children and adolescents age 2 to 19 years, the prevalence of fatty liver adjusted for age, gender, race, and ethnicity is estimated to be 9.6%. Fatty liver prevalence increases with age, ranging from 0.7% for ages 2 to 4 up to 17.3% for ages 15 to 19 years. Fatty liver prevalence differs significantly by race and ethnicity (Asian: 10.2%; black: 1.5%; Hispanic: 11.8%; white: 8.6%). The highest rate of fatty liver was seen in obese children (38%). CONCLUSIONS. Fatty liver is the most common liver abnormality in children age 2 to 19 years. The presence of macrovesicular hepatic steatosis in ∼1 of every 10 children has important ramifications for the long-term health of children and young adults. The influence of the risk factors identified should be taken into consideration in the development of protocols designed to screen at-risk children and adolescents.

Histopathology of pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common in children and adolescents. However, standard histological criteria for pediatric NAFLD and NASH are undeveloped. We reviewed consecutive patients ages 2 to 18 years with biopsy‐proven NAFLD diagnosed between 1997 and 2003. Biopsies were evaluated by two pathologists for individual features of steatohepatitis. Agglomerative hierarchical cluster analysis demonstrated two different forms of steatohepatitis. Type 1 was characterized by steatosis, ballooning degeneration, and perisinusoidal fibrosis; type 2 was characterized by steatosis, portal inflammation, and portal fibrosis. The study included 100 children with NAFLD. Simple steatosis was present in 16% of subjects, and advanced fibrosis was present in 8%. Type 1 NASH was present in 17% of subjects, and type 2 NASH was present in 51%. Boys were significantly (P < .01) more likely to have type 2 NASH and less likely to have type 1 NASH than girls. The NASH type differed significantly (P < .001) by race and ethnicity. Type 1 NASH was more common in white children, whereas type 2 NASH was more common in children of Asian, Native American, and Hispanic ethnicity. In cases of advanced fibrosis, the pattern was generally that of type 2 NASH. In conclusion, type 1 and type 2 NASH are distinct subtypes of pediatric NAFLD, and type 2 is the most common pattern in children. NASH subtypes should be considered when interpreting liver biopsies and planning studies of the pathophysiology, genetics, natural history, or response to treatment in pediatric NAFLD. (HEPATOLOGY 2005;42:641–649.)

Obesity, insulin resistance, and other clinicopathological correlates of pediatric nonalcoholic fatty liver disease.

OBJECTIVE To describe the clinical characteristics of nonalcoholic fatty liver disease (NAFLD) in children, including insulin resistance, and to test for correlation with liver pathology. STUDY DESIGN A retrospective review of children with biopsy-proven NAFLD at Childrens Hospital San Diego from 1999 to 2002. Liver biopsy specimens were independently reviewed by two pathologists. RESULTS Children with NAFLD (n=43) were mostly male (70%), Hispanic American (53%) and obese (88%). The criteria for insulin resistance were met by 95% of subjects. Steatosis was predicted by the combination of quantitative insulin sensitivity check index, age, and ethnicity (P<.0001). Portal inflammation was predicted by the combination of ALT and fasting insulin (P=.0009). Perisinusoidal fibrosis was predicted by the combination of AST, fasting insulin, and BMI Z score (P<.0001). Portal fibrosis was predicted by the combination of right upper quadrant pain and homeostasis model assessment of insulin resistance (P=.0028). CONCLUSIONS We identified significant predictors of liver pathology in children with NAFLD. Children being evaluated for NAFLD should be screened for insulin resistance, which is nearly universal and correlates with liver histology.

Serum aminotransferase levels and platelet counts as predictors of degree of fibrosis in chronic hepatitis C virus infection.

OBJECTIVE:In patients with chronic hepatitis C virus (HCV) infection, liver fibrosis stage is a prognostic factor for therapy outcome. So far, a liver biopsy is necessary to determine disease stage accurately. We sought to develop a simple, noninvasive method of accurately predicting the degree of liver fibrosis in chronic HCV infection.METHODS:We retrospectively studied 211 consecutive patients with chronic HCV, who received a liver biopsy at the Liver Center of the University of California, San Diego. A total of 58 of these patients had a positive history of alcohol abuse, and we analyzed them separately in a sensitivity analysis. AST/ALT ratio and platelet counts were determined in all patients. Fibrosis was staged using the METAVIR score.RESULTS:Both AST/ALT ratio and platelet counts correlated significantly with the disease stage (r = 0.190, p = 0.006, and r = − 0.543, p < 0.00, respectively). In a sensitivity analysis, there was no correlation between AST/ALT ratio and disease stage for patients with a history of alcohol abuse. For patients without history of alcohol abuse, the correlation between disease stage, AST/ALT ratio, and platelet counts was r = 0.297, p < 0.00, and r = 0.560, p < 0.00, respectively. In these patients, AST/ALT ratio ≥1 in combination with a platelet count of <150,000/mm3 can identify patients with severe fibrosis or cirrhosis (stages 3 and 4) with a positive predictive value of 93.1%. Sensitivity, specificity, and negative predictive value were 41.2%, 99.1%, and 85.0%, respectively. In patients with ALT/AST ratio of <1 or platelet counts of >150,000/mm3, these laboratory parameters cannot predict liver fibrosis stage.CONCLUSION:AST/ALT ratio in combination with platelet counts may obviate a liver biopsy for fibrosis staging in some patients with chronic HCV infection.

Pediatric nonalcoholic fatty liver disease: a critical appraisal of current data and implications for future research.

Although population prevalence is very difficult to establish, nonalcoholic fatty liver disease (NAFLD) is probably the most common cause of liver disease in the preadolescent and adolescent age groups. There seems to be an increase in the prevalence of NAFLD, likely related to the dramatic rise in the incidence of obesity during the past 3 decades. Despite an increase in public awareness, overweight/obesity and related conditions, such as NAFLD, remain underdiagnosed by health care providers. Accurate diagnosis and staging of nonalcoholic steatohepatitis (NASH) requires liver biopsy. The development of noninvasive surrogate markers and the advancements in imaging technology will aid in the screening of large populations at risk for NAFLD. Two distinct histological patterns of NASH have been identified in the pediatric population, and discrete clinical and demographic features are observed in children with these 2 patterns. The propensity for NASH to develop in obese, insulin-resistant pubertal boys of Hispanic ethnicity or a non-Hispanic white race may provide clues to the pathogenesis of NAFLD in children. The natural history of pediatric NASH has yet to be defined, but most biopsies in this age group demonstrate some degree of fibrosis. In addition, cirrhosis can be observed in children as young as 10 years. While the optimal treatment of pediatric NAFLD has yet to be determined, lifestyle modification through diet and exercise should be attempted in children diagnosed with NAFLD. A large, multicenter trial of vitamin E and metformin is underway as part of the NASH clinical research network.

Hyperlactatemia and Hepatic Abnormalities in 10 Human Immunodeficiency Virus-Infected Patients Receiving Nucleoside Analogue Combination Regimens

During a 6-and-a-half month period, we identified 10 human immunodeficiency virus (HIV)-infected men who were receiving antiretroviral regimens, including nucleoside analogues, and who developed unexplained reproducible hyperlactatemia in association with either abdominal symptoms or an unaccounted-for elevated alanine aminotransferase level, or both. After careful consideration of the possible etiologies, antiretrovirals were discontinued; lactate levels normalized in all patients. The estimated incidence of this phenomenon in our clinic was 20.9 cases per 1000 person-years of nucleoside analogue treatment. These observations extend the spectrum of the nucleoside analogue-induced lactic acidosis/hepatic steatosis syndrome by the identification of a subtle and perhaps earlier form, which has characteristic symptoms and laboratory abnormalities, and a favorable prognosis on discontinuation of antiretroviral therapy.

Magnetic resonance elastography predicts advanced fibrosis in patients with nonalcoholic fatty liver disease: A prospective study

Retrospective studies have shown that two‐dimensional magnetic resonance elastography (2D‐MRE), a novel MR method for assessment of liver stiffness, correlates with advanced fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). Prospective data on diagnostic accuracy of 2D‐MRE in the detection of advanced fibrosis in NAFLD are needed. The aim of this study is to prospectively assess the diagnostic accuracy of 2D‐MRE, a noninvasive imaging biomarker, in predicting advanced fibrosis (stage 3 or 4) in well‐characterized patients with biopsy‐proven NAFLD. This is a cross‐sectional analysis of a prospective study including 117 consecutive patients (56% women) with biopsy‐proven NAFLD who underwent a standardized research visit: history, exam, liver biopsy assessment (using the nonalcoholic steatohepatitis Clinical Research Network histological scoring system), and 2D‐MRE from 2011 to 2013. The radiologist and pathologist were blinded to clinical and pathology/imaging data, respectively. Receiver operating characteristics (ROCs) were examined to assess the diagnostic test performance of 2D‐MRE in predicting advanced fibrosis. The mean (± standard deviation) of age and body mass index was 50.1 (± 13.4) years and 32.4 (± 5.0) kg/m2, respectively. The median time interval between biopsy and 2D‐MRE was 45 days (interquartile range: 50 days). The number of patients with fibrosis stages 0, 1, 2, 3, and 4 was 43, 39, 13, 12, and 10, respectively. The area under the ROC curve for 2D‐MRE discriminating advanced fibrosis (stage 3‐4) from stage 0‐2 fibrosis was 0.924 (P < 0.0001). A threshold of >3.63 kPa had a sensitivity of 0.86 (95% confidence interval [CI]: 0.65‐0.97), specificity of 0.91 (95% CI: 0.83‐0.96), positive predictive value of 0.68 (95% CI: 0.48‐0.84), and negative predictive value of 0.97 (95% CI: 0.91‐0.99). Conclusions: MRE is accurate in predicting advanced fibrosis and may be utilized for noninvasive diagnosis of advanced fibrosis in patients with NAFLD. (Hepatology 2014;60:1919–1927)

Association Between Metabolic Syndrome and Liver Histology Among Children With Nonalcoholic Fatty Liver Disease

OBJECTIVES:Nonalcoholic steatohepatitis (NASH) is considered the hepatic manifestation of metabolic syndrome (MetS) among adults. Emerging data suggest that MetS may be associated with nonalcoholic fatty liver disease (NAFLD) in children as well. We sought to determine whether MetS or its component features are associated with specific histological features or severity of NAFLD.METHODS:Children and adolescents aged 6–17 years enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) with clinical data obtained within 6 months of liver biopsy were included. MetS was defined as the presence of three or more of the following features as determined by application of age-adjusted normative values: central obesity, dyslipidemia, impaired fasting glucose, and elevated blood pressure. Liver biopsies were evaluated by the Pathology Committee of the NASH CRN.RESULTS:Two hundred fifty four children were included in the analysis, of whom 65 (26%) met specified criteria for MetS. Among children with MetS, there is a higher proportion of females who were on average older in age and pubertal. The risk of MetS was greatest among those with severe steatosis (odds ratio (OR)=2.58 for grade 3 vs. grade 1 steatosis, P=0.001). The presence of hepatocellular ballooning was also significantly associated with MetS (OR=2.10, P=0.03). Those with advanced fibrosis (stage 3/4) had an OR for MetS of 3.21 (P=0.04) vs. those without fibrosis (stage 0). Borderline zone 1 or definite NASH patterns compared with “not NASH” were strongly associated with MetS (OR=4.44, P=0.005 and OR=4.07, P=0.002, respectively). The mean NAFLD Activity Score (NAS) was greater among children with MetS vs. those without (4.8 ± 1.4 vs. 4.3 ± 1.4, P=0.01). Central obesity was significantly associated with steatosis, fibrosis, hepatocellular ballooning, and NAFLD pattern. Insulin resistance was significantly associated with steatosis, fibrosis, hepatocellular ballooning, NAS, and NAFLD pattern.CONCLUSIONS:MetS is common among children with NAFLD and is associated with severity of steatosis, hepatocellular ballooning, NAS, NAFLD pattern, and the presence of advanced fibrosis. Individual MetS features, particularly central obesity and insulin resistance, were also associated with severity of NAFLD. MetS features should be considered in children with NAFLD as individually and collectively they help identify children with more advanced disease.

Morbidity, Mortality, and Placental Pathology in Excessively Long Umbilical Cords: Retrospective Study

The purpose of this study was to compare specific fetal, maternal, and placental factors, including neonatal morbidity and mortality, in infants with umbilical cords (UCs) of normal length to the same factors in infants with excessively long umbilical cords (ELUCs). We performed an 18-year retrospective chart review of the medical records of mothers and infants with ELUCs (926 cases) and normal-length UCs (200 cases) and recorded maternal factors, fetal factors, and neonatal outcomes. Corresponding placental pathologic reports and slides were reviewed. Statistical analysis comparing the two groups included univariate and multivariate analyses.ELUCs were significantly associated with certain maternal factors (systemic diseases, delivery complications, increased maternal age), fetal factors (non-reassuring fetal status, respiratory distress, vertex presentation, cord entanglement, fetal anomalies, male sex, increased birth weight), gross placental features (increased placental weight, right-twisted cords, markedly twisted cords, true knots, congestion), and microscopic placental features (nucleated red blood cells, chorangiosis, vascular thrombi, vascular cushions, meconium, increased syncytial knots, single umbilical artery). Some of these histopathologic features have previously been associated with fetal hypoxia and/or altered blood flow in the placenta. Infants with ELUCs were found to be at a significantly increased risk of brain imaging abnormalities and/or abnormal neurological follow-up. In addition, mothers with a history of an ELUC are at increased risk of a second long cord.