Evaluation and management of non-alcoholic steatohepatitis

Treatment of patients with non-alcoholic fatty liver disease: current views and perspectives

Non-alcoholic fatty liver disease is considered a component of the metabolic syndrome associated with obesity. Problems still exist concerning non-alcoholic fatty liver disease patients in clinical practice, for example: (a) how to diagnose non-alcoholic fatty liver disease and its type; (b) how to select patients candidate to treatment; (c) how to treat selected patients. Non-alcoholic fatty liver disease includes steatosis and non-alcoholic steatohepatitis, but only non-alcoholic steatohepatitis evolves into cirrhosis and the absolute risk of mortality for non-alcoholic fatty liver disease is low. As yet, no tools, other than liver biopsy, are available to differentiate the various types of non-alcoholic fatty liver disease. Many drugs are, currently, under study to treat non-alcoholic fatty liver disease, even if well-performed trials are until necessary to define the best treatment. At the moment, the entity of the problem and the characteristics of patients frequently put the physician, in clinical practice, to choose the therapeutic approach arbitrarily which is considered more effective for each individual patient. Probably the future will consider the possibility of treating non-alcoholic fatty liver disease with more than one drug, by considering the various aspects and degree of this syndrome. Actually each physician should select the individual treatment on the basis of his/her knowledge and experience, by never forgetting the old saying 'primum non nocere'. However, the epidemiological entity of the problem, the characteristics of the patients, generally young, the frequent lack of clinical evidence of involvement of the liver, are all the factors that require vast well-performed clinical trials in order to define the best therapeutic approach for each individual patient.

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.

A pilot study of atorvastatin treatment in dyslipemid, non-alcoholic fatty liver patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of liver injury. Currently, there are no proven effective therapies available. Atorvastatin is a new 3-hydroxy-3-metylglutaryl coenzyme A reductase inhibitor that reduces lipid serum levels.

AIM

To evaluate the effectiveness and safety of atorvastatin in dyslipemid, non-alcoholic fatty liver patients.

PATIENTS AND METHODS

We prospectively enrolled 25 patients with NAFLD; 22 of them completed the study. Body mass index, serum lipids, liver function tests and liver density assessed by echography were measured at baseline and after 1, 3, 6, 9 and 12 months of treatment. Normalization of transaminases and/or improvement in liver density were treatment end points. Patients received atorvastatin (10-80 mg/daily) according to basal serum choleresterol levels; additionally, they were given standard weight-loss counselling and encouraged to follow a low fat diet.

RESULTS

All 22 patients (14 men, mean age 47 +/- 10 years) had high cholesterol levels at baseline and 11 (44%) also presented high trygliceride levels. After 6 months of treatment, eight patients (36.3%) presented normal transaminase levels. The remaining patients continued treatment for 12 months when 20% of patients presented with normal transaminase levels, while the other patients showed a 10% reduction in basal levels. Mean cholesterol levels were 268.5 +/- 44.2 and 186.8 +/- 14.4 mg/dL before and after treatment, respectively (P < 0.05). The mean body mass index was 27.4 +/- 3.1 at baseline and 26.3 +/- 2.8 kg/cm2 at the end of treatment (P > 0.05). No side effects were reported.

CONCLUSIONS

Serum aminotransferase and lipid levels were reduced significantly in all patients with atorvastatin treatment. Therapy with atorvastatin in NAFLD patients with hyperlipidemia was found to be both effective and safe.

Increased production of IL-1alpha and TNF-alpha in lipopolysaccharide-stimulated blood from obese patients with non-alcoholic fatty liver disease

Enhanced pro-inflammatory cytokine production is considered a pathogenic factor in non-alcoholic fatty liver disease (NAFLD). Peripheral blood production of interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) was studied in relation to the severity of histological changes of the liver in obese NAFLD patients. Basal levels in serum and production of IL-1alpha and TNF-alpha in peripheral blood cell cultures after stimulation with lipopolysaccharide (enzyme-linked immunoabsorbent assays) were measured in 11 patients with steatosis and 15 with steatohepatitis, who underwent gastrectomy with a gastro-jejunal anastomosis in roux and Y, and in 9 controls who underwent anti-reflux surgery. Production of IL-1alpha and TNF-alpha was 122 and 67% higher in patients with steatosis than control values, respectively. In patients with steatohepatitis, IL-1alpha production was 300 and 80% higher and that of TNF-alpha 110 and 26% higher, as compared with controls and steatosis patients, respectively. Production of IL-1alpha was positively correlated with that of TNF-alpha (r=0.78, p<0.0001). IL-1alpha and TNF-alpha production were both positively correlated with the degree of steatosis (r=0.68, p<0.001 and r=0.74, p<0.0001) and steatohepatitis (r=0.77 and r=0.75, p<0.0001) at liver biopsy, and with the homeostasis model assessment index (r=0.73, p<0.0001 and r=0.63, p<0.01), respectively. Basal serum IL-1alpha and TNF-alpha levels were comparable in the three groups studied. It is concluded that elevated production of IL-1alpha and TNF-alpha by in vitro stimulated whole blood cell cultures occurs in NAFLD obese patients, which might play a pathophysiological role upon inflammatory leukocyte infiltration of the liver.

Mitochondrial dysfunction in NASH: causes, consequences and possible means to prevent it

Calorie-enriched diet and lack of exercise are causing a worldwide surge of obesity, insulin resistance and lipid accretion in liver (i.e. hepatic steatosis), which can lead to steatohepatitis. Steatosis and nonalcoholic steatohepatitis (NASH) can also be induced by drugs such as amiodarone, tamoxifen and some antiretroviral drugs, including stavudine and zidovudine. There is accumulating evidence that mitochondrial dysfunction (more particularly respiratory chain deficiency) plays a key role in the physiopathology of NASH whatever its initial cause. In contrast, the mitochondrial beta-oxidation of fatty acids can be either increased (as in insulin resistance-associated NASH) or decreased (as in drug-induced NASH). However, in both circumstances, generation of reactive oxygen species (ROS) by the damaged respiratory chain can be augmented. ROS generation in an environment enriched in lipids in turn induces lipid peroxidation which releases highly reactive aldehydic derivatives (e.g. malondialdehyde) that have diverse detrimental effects on hepatocytes and other hepatic cells. In hepatocytes, ROS, reactive nitrogen species and lipid peroxidation products further impair the respiratory chain, either directly or indirectly through oxidative damage to the mitochondrial genome. This consequently leads to the generation of more ROS and a vicious cycle occurs. Mitochondrial dysfunction can also lead to apoptosis or necrosis depending on the energy status of the cell. ROS and lipid peroxidation products also increase the generation of several cytokines (TNF-alpha, TGF-beta, Fas ligand) playing a key role in cell death, inflammation and fibrosis. Recent investigations have shown that some genetic polymorphisms can significantly increase the risk of steatohepatitis and that several drugs can prevent or even reverse NASH. Interestingly, most of these drugs could exert their beneficial effects by improving directly or indirectly mitochondrial function in liver. Finding a drug, which could fully prevent oxidative stress and mitochondrial dysfunction in NASH is a major challenge for the next decade.

Effects of compound from Chinese medicine on oxidation and anti-oxidation system of rat liver with steatohepatitis induced by high-fat diets

AIM: To explore the action of oxygen stress and lipid peroxidation in the establishment of steatohepatitis and the action mechanisms of compound from Chinese medicine (CCM) in the treatment of steatohepatitis in rats fed by high-fat diets.

METHODS: Sixty male Sprague Dawley rats were randomly assigned into 6 groups. The rats fed by normal food served as the controls. The rats in model groups (Ⅰ, Ⅱ) were fed with high-fat diets, and those in medication Ⅰ and Ⅱ group were given CCM 9 and 13 wk after high-fat diets feeding. The rats in diet therapeutic group were fed with normal food 13 wk after high-fat diet feeding. The animal in control, model Ⅰ, and medication Ⅰ group were killed at 12 wk, and the rest ones were killed at 16 wk. Blood sample were collected for the detection of serum aspartate transaminase (AST), alanine aminotransferase (ALT), and glutathione perioxidase (GSH-PX), and liver tissues were obtained for the detection of malondialdehyde (MDA) contents, superoxide dismutase (SOD) activity, total antioxidative capacity (T-AOC), nitric exide (NO), inducible nitric oxide synthase (iNOS) and glutathione (GSH) levels. The histological changes were observed under light microscope.

RESULTS: Pure fatty liver was formed in the model rats at 12, and fatty hepatitis was established at 16 wk. In comparison with those of normal rats, the contents of MDA were increased (6.45±1.07, 8.38±1.32 µmol/g vs 5.08±0.91 µmol/g, P <0.01) but anti-oxide SOD (171±14, 148±26 kNU/gt vs 198±25 kNU/gt, P <0.05 and P <0.01), GSH (40.8±5.1, 35.0±9.0 mg/g vs 48.5±7.6 mg/g, P <0.05 and P <0.01), GSH-PX (11.2±1.5, 10.3±1.8 µmol/L vs 16.4±3.7 µmol/L, P <0.01) contents were decreased significantly. The severity degree of hepatic fatty degeneration aggravated with the prolonging of the high-fat diet given time. In comparison with those of model rats, the markers such as MDA, SOD, GSH, and GSH-PX etc. were all significantly improved in the medication rats (P <0.05 or P <0.01), and the degree of fatty degeneration was also alleviated. Light or moderate fatty degeneration was observed in diet therapeutic rats, and the relative markers were not notably different from those of model group.

CONCLUSION: Oxygen stress and lipid peroxidation play a key role in the establishment of nonalcoholic steatohepatitis in rats, and the compound of Chinese medince has therapeutic effect on nonalcoholic steatohepatitis by anti-lipid peroxidation.