Therapeutic Options in Non-Alcoholic Steatohepatitis (NASH). Are all Agents Alike? Results of a Preliminary Study

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1 Therapy of non-alcoholic steatohepatitis Therapeutic Options in Non-Alcoholic Steatohepatitis (NASH). Are all Agents Alike? Results of a Preliminary Study Eugen Florin Georgescu 1, Marius Georgescu 2 1) Department Internal Medicine 2, Filantropia University Hospital. 2) Department Internal Medicine 2, Emergency University Hospital, Craiova Abstract Aim. The evaluation of the efficacy of ursodeoxycholic acid (UDCA), pentoxifylline, losartan, and atorvastatin in non-alcoholic steatohepatitis (NASH) treatment. Method. 48 patients (25 males/23 females, aged years) with histologically confirmed NASH were enrolled between 2001 and The batch was divided into four groups: A (10 dyslipidemic patients, receiving atorvastatin 10 mg/day), P (13 nonhypertensive/ nondyslipidemic patients receiving pentoxifylline 400 mg bid), L (12 hypertensive patients, treated with losartan, 50 mg/day) and U (13 nonhypertensive patients receiving UDCA 15 mg/kg/day). Mean duration of treatment was weeks. Body mass index, liver biopsy and serum level of alanin-aminotransferase (ALT), gammaglutamyl transpeptidase (GGT), alkaline phos-phatase (AP), total cholesterol (TC) and triglycerides (TG) were determined at inclusion and at the end of treatment. Liver biopsy samples were evaluated for necroinflammation, steatosis and fibrosis (Brunt s score). Results. In group A, a significant reduction of ALT, GGT, TC and AP was noticed. Histology showed diminished steatosis, but no improvement of fibrosis and necroinflammation. In groups P and L we found a reduction of mean ALT and GGT levels and necroinflammatory score. Group U presented a significant reduction in ALT and GGT levels, without improvement in steatosis, necroinflammation or fibrosis. Conclusion. Atorvastatin and losartan proved to be efficient in the treatment of dyslipidemia- and hypertension-associated NASH, by improving both biochemical parameters and steatosis/ necroinflammation. Pentoxifylline showed similar efficacy in non-hypertensive/ non-dyslipidemic patients, while UDCA did not improve the histological score although it improved the biochemical parameters. J Gastrointestin Liver Dis March 2007 Vol.16 No 1, Address for correspondence: Conf. Dr. E.F. Georgescu Dept.of Internal Medicine 2 Filantropia University Hospital Str. Constantin Brancusi nr Craiova, Romania efg@usa.net Key words Non-alcoholic steatohepatitis - pentoxifylline - losartanatorvastatin - ursodeoxycholic acid - NAFLD activity score Introduction Nonalcoholic fatty liver disease (NAFLD) is a condition characterized by hepatic steatosis in the absence of a history of significant alcohol use or other known liver disease (1). Its progressive form is called nonalcoholic steatohepatitis (NASH). The prevalence of NAFLD averages 20% and that of NASH 2% to 3%, making these conditions the most common liver diseases in the United States and developed countries, including Eastern Europe. NAFLD is a spectrum of liver disease having as its hallmark the accumulation of large-droplet fat in hepatocytes (2). Fatty infiltration of the liver exceeds 5 to 10% by weight. NAFLD consists of a spectrum of disorders ranging from simple fatty liver (steatosis without liver injury), NASH (steatosis with inflammation), and fibrosis/cirrhosis that resembles alcohol-induced liver disease but develops in individuals who are not heavy drinkers. This metabolic disorder occurs mainly in overweight or obese individuals, but as nowadays NAFLD is emerging as one of the main causes of chronic liver disease, it is considered to be the hepatic component of the metabolic syndrome, whose central features include obesity, hyperinsulinemia, peripheral insulin resistance, diabetes, dyslipidemia, and hypertension (3-5). The National Cholesterol Education Project Adult Treatment Panel (NCEP-ATP III) (6) included a widely used definition of the metabolic syndrome in the 2001 guidelines, which requires any 3 of the following features: abdominal obesity with waist circumference more than 102 cm (40 inches) in men and 88 cm (35 in) in women, triglycerides >150 mg/dl (2 mmol/l), HDL cholesterol less than 40 mg/dl (1 mmol/l) in men and 50 mg/dl (1 mmol/l) in women, blood pressure >130/>85 mmhg (or treatment for hypertension), fasting glucose >110 mg/dl (6 mmol/l). The pathogenic mechanism involves hyperinsulinemia and hepatic insulin resistance,

2 40 although the complete succession of events is still poorly understood. NASH has been documented to have the potential to progress to cirrhosis and hepatocellular carcinoma, being a leading cause of cryptogenic cirrhosis in which specific clinical laboratory or pathological features cannot be identified (7). Although it is accepted that steatohepatitis is a pattern of injury composed of several specific features, it is difficult to define exact diagnostic criteria that all pathologists agree upon to precisely distinguish NAFLD cases with steatohepatitis from those with only steatosis and inflammation. Several features showed significant association with the diagnosis of steatohepatitis for both adults and children, including lobular inflammation, ballooning degeneration, and fibrosis. Very few trials have been conducted with drugs having definite therapeutic benefits in NASH and, as a consequence, no specific therapy has been approved for this condition. Metformin, thiazolidinediones, HMG-CoA reductase inhibitors, antioxidants, pentoxifylline, lipoprotein lipase activators and low caloric diets have been tested and repeatedly evaluated in order to estimate their efficiency, without any clear-cut conclusion over their benefits. Controversy still exists over the optimal recognition, diagnosis and management of NASH, and treatment recommendations are still unclear. Patients and methods The aim of this prospective, non-randomized and uncontrolled study, carried out on an outpatient database was to evaluate the efficiency of ursodeoxycholic acid (UDCA), pentoxifylline, losartan, and atorvastatin in treatment of NASH. Forty-eight patients with histologically confirmed NASH were enrolled between 2001 and The study included 17 diabetic patients with no hypertension or obesity (subgroup DM), 12 hypertensive patients, nondiabetic and non-obese (subgroup HT) and 19 obese and dyslipidemic patients with no hypertension or diabetes (subgroup Ob/DL). Considering the well-known poor compliance to hepatic biopsy, as well as ethical reasons, we decided neither to include controls nor to use placebo in our study, because otherwise a large number of patients had to support two liver biopsies and receive no active treatment. The batch was divided into four therapeutic groups: A (10 dyslipidemic patients, receiving atorvastatin Georgescu and Georgescu 20 mg/day), P (13 normotensive/nondyslipidemic patients receiving pentoxifylline 400 mg bid.), L (12 hypertensive patients, treated with losartan, 50 mg/day) and U (13 normotensive patients receiving UDCA 15 mg/kg/day). A distribution synopsis of the study patients into the main groups is shown in Table I. All patients (25 males/23 females) were Caucasians, their mean age was years and had no history of drug and/or alcohol abuse. NASH was diagnosed in these patients 1-3 months before inclusion in the study. No medication for their condition had been prescribed before and no concomitant medication was allowed during the study, apart from insulin for the diabetics, who had to be metabolically stable at the date of inclusion. Insulinsensitizing agents were not allowed 6 months before inclusion and during the study. In diabetics, glycemic control was obtained only by diet in 11 patients, and by using insulin in another 6, following the prescriptions of the diabetologist (mean daily dose units). No change in insulin type was allowed, but if the blood glucose levels were too high or too low current modification of daily dosage was permitted. No dietary restriction or lifestyle modifications were imposed in all patients, except current recommendations made by their cardiologist or diabetologist at the time of their regular visits. Moreover, as stated in the informed consent, no dramatic lifestyle changes were permitted during the study (e.g. low-calorie diets, intensive physical training, surgery for obesity and so on). Treatment compliance was rigorously monitored. Alcohol consumption was strictly forbidden. Patients with history of alcohol abuse or chronic intake (assumed or confirmed by their family) were not included in the study. In monitoring alcohol intake we utilized a questionnaire adapted from Behavioral Risk Factor Surveillance System 2006 Questionnaire (8) administered at each visit. Little amounts of alcohol were allowed occasionally, but no more than 2 drinks/week, 1 drink being defined as one standard US alcoholic drinks (approximately 14 g ethanol i.e. 12 oz of beer, 5 oz of wine, or 1.5 oz of liquor; 1 US oz = approx. 30 ml). The study design previewed one screening visit at inclusion (V1), two regular visits (V2 and V3) at 10, and 20 weeks after inclusion and one end-of treatment visit at 30 weeks (V4). Patients were permitted to continue treatment after the last visit if significant improvement in their condition was noticed, so the mean duration of surveillance was weeks at the closeout of the database. Table I Distribution of study medication in subgroups. A atorvastatin; P pentoxifylline; L losartan; U ursodeoxycholic acid (therapeutic groups) Number A P L U Total (%) DM 0 13 (76.47) 0 4 (23.53) 17 (100) HT (100) 0 12 (100) Ob/DL 10 (52.63) (47.37) 19 (100) Total 10 (20.83) 13 (27.08) 12 (25.00) 13 (27.08) 48 (100)

3 Therapy of non-alcoholic steatohepatitis 41 Body mass index (BMI), liver biopsy and serum level of alanin-aminotransferase (ALT), γ-glutamyl transpeptidase (GGT), alkaline phosphatase (AP), total cholesterol (TC) and triglycerides (TG) were determined at inclusion and at the end of treatment. Blood glucose (G) levels were also monitored in all patients at each visit. Because histological evaluation remains the only valuable tool in assessing the degree of steatosis, necroinflammation and fibrosis in NASH, as well as in distinguishing NASH from simple steatosis or steatosis with inflammation, acceptance of two hepatic needle biopsies was one of the inclusion criteria. Consequently, visit 1 and visit 4 required biopsies for validation. We considered as an acceptable interval for performing biopsy + 2 weeks prior or after the first and respectively last visit of the study. According to protocol, liver biopsy evaluated necroinflammatory score, steatosis, and fibrosis using the system for semi-quantitative evaluation for the lesions recognized in NASH developed by Brunt (9) and colleagues in Based on these criteria, the Pathology Committee of the NASH Clinical Research Network designed and validated a histological (10) 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). The proposed NAS is the sum of steatosis, lobular inflammation, and hepatocellular ballooning scores and a NAS greater than 5 correlates with the diagnosis of NASH, while scores of less than 3 were considered as not NASH. Histopathologists were asked to quantify the lesions identified on the bioptic fragments, this score. The NAS scores at inclusion (Score 1) and at the study termination (Score 2) were stored in the database and compared between the therapeutic groups. Results The screening visit (inclusion) consisted of a clinical examination and body mass index determination (mean BMI /-5.54). Biochemical tests at inclusion are shown in Table II. No difference was noticed between groups regarding ALT, GGT, AP values at V1, while TC and TG were significantly higher in obese/dyslipidemic patients as well as glucose levels in diabetics, as shown by Fisher s exact test with 95% CI. Body mass index was significantly higher in obese / dyslipidemic patients than in the diabetic and the hypertensive ones. As in the whole group, in the smaller four therapeutic subgroups (A, P, L and U) no differences in ALT, GGT and AP values were found at inclusion. BMI was significantly higher in the atorvastatin and ursodeoxycholic groups than in the other two, without any difference between A and U (Table III). Total cholesterol was significantly higher in the atorvastatin group compared with pentoxifylline, with no difference regarding the other two groups, while TGs were elevated in A and U groups compared with A and L groups. Glucose levels were higher in P group because 13 of 17 diabetic patients were assigned to this therapy. The mean NAS score at inclusion (Score 1) was , with no significant differences between the four therapeutic groups as shown by Fisher s exact test (p>0.05 for all comparison score1,a/score1,p/score1,l/score1u). Subsequently, no significant difference was noticed between steatosis, necroinflammation, ballooning and fibrosis in groups A, P, L and U at inclusion (p=0.05). Detailed data for Score 1 at V1 are shown in Table IV. The assessment of biochemical parameters after completion of the study in all patients is showed in Table V. Significant reduction of ALT, GGT, TC and AP were noticed in group A. Groups P, L and U experienced similar improvements in ALT and GGT values (p<0.05), but no statistically significant decrease of AP, TC and TG in any of Table II Mean values for biochemical parameters and BMI in subgroups at inclusion Diabetes mellitus (DM) Hypertension (HT) Obesity and dyslipidemia (Ob/Dl) All groups Mean SD Mean SD Mean SD Mean SD ALT GGT TC TG AP G BMI Table III Mean values of biochemical parameters and BMI in therapeutic groups at inclusion Atorvastatin Pentoxifylline Losartan Ursodeoxycholic acid Mean SD Mean SD Mean SD Mean SD ALT GGT TC TG AP G BMI

4 42 Georgescu and Georgescu Table IV Mean values for NAS scores at V1 and V4 Atorvastatin Pentoxifylline Losartan Ursodeoxycholic acid Mean SD Mean SD Mean SD Mean SD Score Score Mean diff. Score1/ Score 2 p < < < these groups was noticed using the bilateral t-test (Table VI). No significant variation has been noticed regarding glucose levels and BMI inside groups. The highest decrease of ALT values appeared in the first 10 weeks of treatment in all therapeutic groups, with no important variation during the treatment course. After returning to quite-normal range, the ALT values remained stable in all four groups, until the end of treatment (Fig.1). GGT values also diminished at 10 weeks of treatment, with a descending trend over the treatment phase, even if somewhat lower rates were observed between V2 and V 4. At the end of the study, normalization of ALT values was attended in % +/ % from patients, all groups included. Percentages varied from / (group U) to / (group P) leading to the observation that none of all four agents was able to normalize ALT in more than a half of patients (Fig. 2). Despite insignificant variation of BMI during the study, the slight decrease of this parameter correlates well with the global decrease of ALT values in the whole group (p=0.0426). However, in therapeutic groups, correlation between decrease of ALT and BMI reduction is not so obvious (Fig. 3), as in A and U groups we found statistical significance for this aspect (p= and respectively) while in P and L not (p > 0.05). Histopathological evaluation showed a mean NAS score at termination (see Table IV) of , significantly lower than Score 1 (p<0.05). The lowest NAS score at the end of study was in the losartan group and the highest in the UDCA group, in which no therapeutical benefit was found by statistical analysis. A comparison between NAS scores and their components at inclusion vs. termination in all therapeutic groups is shown in Fig.4. Improvement in one or more NAS components was noticed only in A, L and P subgroups, but no fibrosis amelioration was found in any of the four. In the UDCA group, no significant improvement in steatosis, necroinflammation or fibrosis was found, despite biochemical amelioration. The steatosis score significantly diminished in the A, L and P groups, but only P and L groups experienced significant statistical improvement of necroinflammation. Discussion Our results are in accordance with other trials, even if our data are scarce. In brief, all the four drugs induced significant decreases in ALT and GGT values, while only atorvastatin significantly reduced the AP, TC and TG levels. As we already stressed, contribution of BMI reduction at biochemical improvement was not so important in our Table V Mean values for biochemical parameters and BMI at study termination Atorvastatin Pentoxifylline Losartan Ursodeoxycholic acid Mean SD Mean SD Mean SD Mean SD ALT GGT TC TG AP G BMI Table VI Significant differences between biochemical parameters at V1 vs. V4 Atorvastatin Pentoxifylline Losartan Ursodeoxicholic All groups Mean p Mean p Mean p Mean p Mean p diff. diff. diff. diff. diff. ALT (V1) /ALT (V4) < < < GGT (V1) /GGT (V4) 6.70 NS NS AP (V1) /AP (V4) NS NS NS TC (V1) /TC (V4) < NS NS NS < TG (V1) /TG (V4) NS 1.46 NS 5.42 NS NS G (V1) /G (V4) 8.60 NS NS NS 3.38 NS NS BMI (V1) /BMI (V4) 0.60 NS 0.85 NS 0.17 NS 1.38 NS

5 Therapy of non-alcoholic steatohepatitis 43 Fig.1 Variation of biochemical parameters and BMI (95% CI) from V1 to V4 in therapeutic groups. Legend: A atorvastatin; P pentoxifylline; L losartan; U ursodeoxycholic acid (therapeutic groups). opinion, at least in the specific case of this study, but, of course, further developments are necessary to investigate this fact. On the other hand, the histological evaluation revealed significant improvement of two or three of the four components of NAS only in A, L and P subgroups, while in Fig.2 Percentages of ALT normalization at the end of treatment overall and in therapeutic groups. patients receiving UDCA no statistically significant improvement was seen at all. Moreover, fibrosis did not change in any of the four groups, and only steatosis seemed to benefit from pentoxifylline, losartan or atorvastatin treatments. Due to the limited number of patients included in our study, results need to be verified by larger controlled trials, even if poor acceptance of hepatic biopsy remains an important challenge. Apart from this aspect, many histopathological studies which used the same system as us (11-13) showed a remarkable degree of variability in their results, presumably because of differences in patient selection, pharmacological agents and treatment protocols. While, apart from atorvastatin, no other drug influenced TC and TG levels, this seems to be the first option in obese / dyslipidemic patients with NASH. Kiyici et al (14) also observed that the use of atorvastatin in NASH patients with hyperlipidemia was both effective and safe while Balistreri (15) considers that atorvastatin improves serum ALT and lipid levels in patients with NASH. The ability of atorvastatin to reduce cytolysis in NASH patients remains unexplained, as well as the mechanisms involved in this effect. As Innoue et al (16) showed on animal models, it seems that statins

6 44 Georgescu and Georgescu Fig.3 Variation of NAS components in therapeutic groups at V4 vs. V1 (95% CI). Fig.4 Variation of the mean values (95%CI) for steatosis, necroinflammation, hepatocyte balooning and fibrosis, at inclusion versus termination of the study.

7 Therapy of non-alcoholic steatohepatitis improve steatosis and fibrosis by repressing tumor growth factor expression and consequently reducing oxidative stress. Other authors (17) showed that administration of other statins such as lovastatin generated similar effects, possibly mediated through alteration of lipid metabolism. Pentoxifylline determined a fast and deep decrease of ALT and GGT after 10 weeks of treatment without interfering with other biochemical parameters, and this effect remained stable during the whole period of surveillance. Other authors demonstrated similar biochemical improvement under pentoxifylline therapy in pilot studies although no histological data were obtained (18) at least in a large series. Neuner et al and Adams et al (19,20) studied the mechanism of action of pentoxifylline in NASH considering that those patients have high levels of tumor necrosis factor-alpha (TNF-alpha). While production of TNF-alpha is one of the primary events in liver injury triggering the production of various cytokines (21) that recruit inflammatory cells (which in their turn damage hepatocytes and induce fibrogenesis) (22,23), it seems that pentoxifylline decreases lipopolysaccharide-stimulated TNF production (24) and improves hepatic histology, diminishing both steatosis and necroinflammation. By improving biochemical and histological scores in hypertensive patients with NASH, losartan proved to be a valuable agent in this group. The rationale for using angiotensin 2 receptor antagonists in NASH resides upon the observation that the renin-angiotensin system is frequently activated in patients with chronic liver disease and these drugs seem to have antifibrotic effects by interfering hepatic stellate cell proliferation (25). In small studies, losartan showed a significant decrease in blood markers of hepatic fibrosis, and also an improvement in ALT levels. Recently, Yokohama and Nakamura (26) presumed a role for angiotensin II in insulin resistance, oxidative stress and hepatic stellate cell activation, observing improvement in hepatic necroinflammation and fibrosis and a decrease in activated hepatic stellate after administration of losartan. Ursodeoxycholic acid has been tested in patients with NASH because of certain antiapoptotic and immunomodulatory effects (27,28) not absolutely linked to the decrease of endogenous hydrophobic bile acids. As in our study, it showed some benefit by reducing ALT levels as well as the total amount of fat in the liver, but even if its hepatoprotective properties justify the use in many chronic liver diseases, routine use of UDCA in the treatment of NASH still remains under research because of the lack of consistent effects on hepatic histology. Lindor and the UDCA/NASH Study Group (29) reported their findings in 168 patients enrolled in a 2-year randomized, placebo-controlled study using UDCA at a dose of mg/kg/day. All patients had biopsy-proven steatosis > 10% with inflammation and the eendpoints of the trial included changes in liver test results and liver histology. As we also observed, the group finally concluded that although safe and well tolerate, UDCA did not improved steatosis, necroinflammation, or fibrosis compared with placebo, even if some improvement in serum liver biochemistry was noticed. Conclusion Atorvastatin and losartan showed efficacy in the treatment of patients with dyslipidemia- and hypertensionassociated NASH, by improving both biochemical parameters and steatosis / necroinflammation. Pentoxifylline showed similar efficacy in non-hypertensive and nondyslipidemic patients with NASH, while UDCA did not improve histological aspects although it determined significant amelioration of biochemical parameters. No therapeutic agent reversed fibrosis, whilst steatosis was the commonest feature that can be improved by treatment. Necroinflammation is sometimes reversed and sometimes not, pentoxifylline and losartan showing the best results regarding this, but the degree of improvement and the stability of results are yet unknown. References Matteoni CA, Younossi ZM, Gramlich T, Boparai N, Liu YC, McCullough AJ. Nonalcoholic fatty liver disease: a spectrum of clinical and pathological severity. Gastroenterology 1999; 116: Falck-Ytter Y, Younossi ZM, Marchesini G, McCullough AJ. Clinical features and natural history of nonalcoholic steatosis syndromes. Semin Liver Dis 2001; 21: Chitturi S, Farrell GC. Etiopathogenesis of nonalcoholic steatohepatitis. Semin Liver Dis 2001; 21: Diehl AM. Fatty liver, hypertension, and the metabolic syndrome. Gut 2004; 53: Marchesini G, Bugianesi E, Forlani G, et al. Nonalcoholic fatty liver, steatohepatitis, and the metabolic syndrome. Hepatology 2003; 37: Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults. Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III). JAMA. 2001;285: Bacon BR, Farahvash MJ, Janney CG, Neuschwander-Tetri BA. Nonalcoholic steatohepatitis: an expanded clinical entity. Gastroenterology 1994; 107: Division of Adult and Community Health. Behavioral Risk Factor Surveillance System Online Prevalence Data. Atlanta, GA: National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention. At: 9. Brunt EM. Grading and staging the histopathological lesions of chronic hepatitis: the Knodell histology activity index and beyond. Hepatology 2000; 31: Kleiner DE, Brunt EM, Van Natta M, et al. Nonalcoholic Steatohepatitis Clinical Research Network. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology 2005;41: Neuschwander-Tetri BA, Caldwell SH. Nonalcoholic steatohepatitis: summary of an AASLD single topic conference. Hepatology 2003;37:

8 Angulo P. Nonalcoholic fatty liver disease. N Engl J Med 2002; 346: Angulo P, Lindor KD. Treatment of non-alcoholic steatohepatitis. Best Pract Res Clin Gastroenterol 2002;16: Kiyici M, Gulten M, Gurel S, et al. Ursodeoxycholic acid and atorvastatin in the treatment of nonalcoholic steatohepatitis. Can J Gastroenterol 2003; 17: Balistreri WF. Nonalcoholic fatty liver disease - insights and controversies, highlights in liver disease. CME Digestive Disease Week 2006, Medscape 16. Inoue M, Tazuma S, Hyogo S, et al. Pravastatin, a HMG-CoA reductase inhibitor, attenuates hepatic oxidative stress to retard liver fibrogenesis of NAFLD in an in vivo study: An evidence for therapeutic potential of statins on NASH. Gastroenterology. 2006;130:A Avins AL, Manos MM, Levin TR, et al. Lovastatin is not hepatotoxic to patients with pre-existing liver disease. Gastroenterology 2006;130:A Comar KM, Sterling RK. Drug therapy for non-alcoholic fatty liver disease. Aliment Pharmacol Ther 2006;23: Neuner P, Klosner G, Schauer E, et al. Pentoxifylline in vivo down-regulates the release of IL-1 beta, IL-6, IL-8 and tumour necrosis factor-alpha by human peripheral blood mononuclear cells. Immunology 1994; 83: Adams LA, Zein CO, Angulo P, Lindor KD. A pilot trial of pentoxifylline in nonalcoholic steatohepatitis. Am J Gastroenterol 2004; 99: Georgescu and Georgescu 21. Tilg H, Diehl AM. Cytokines in alcoholic and nonalcoholic steatohepatitis. N Engl J Med 2000; 343: Warne JP. Tumour necrosis factor alpha: a key regulator of adipose tissue mass. J Endocrinol 2003; 177: Wigg AJ, Roberts-Thomson IC, Dymock RB, McCarthy PJ, Grose RH, Cummins AG. The role of small intestinal bacterial overgrowth, intestinal permeability, endotoxaemia, and tumour necrosis factor alpha in the pathogenesis of non-alcoholic steatohepatitis. Gut 2001; 48: Duma DG, Ozdemir F, Birben E, et al. Effects of pentoxifylline on TNF-alpha production by peripheral blood mononuclear cells in patients with NASH. Gastroenterology 2006;130:A Yoshiji H, Kuriyama S, Yoshii J, et al. Angiotensin-II type 1 receptor interaction is a major regulator for liver fibrosis development in rats. Hepatology 2001; 34: Yokohama S, Nakamura K, Haneda M. Clinical utility of angiotensin II receptor antagonist. Nippon Rinsho 2006; 64: Lindor KD. Ursodeoxycholic acid for treatment of nonalcoholic steatohepatitis: results of a randomized, placebo-controlled trial. Gastroenterology 2003;124:A Laurin J, Lindor KD, Crippin JS, et al. Ursodeoxycholic acid or clofibrate in the treatment of non-alcohol-induced steatohepatitis: a pilot study. Hepatology 1996;23: Lindor KD, Kowdley KV, Heathcote EJ, et al. Ursodeoxycholic acid for treatment of nonalcoholic steatohepatitis: results of a randomized trial. Hepatology 2004; 39: