Nonalcoholic fatty liver disease Adams, Leon A; Angulo, Paul; Lindor, Keith D
Canadian Medical Association journal,
03/2005, Letnik:
172, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Nonalcoholic fatty liver disease is emerging as the most common chronic liver condition in the Western world. It is associated with insulin resistance and frequently occurs with features of the ...metabolic syndrome. Disease presentation ranges from asymptomatic elevated liver enzyme levels to cirrhosis with complications of liver failure and hepatocellular carcinoma. Current treatment recommendations are limited to weight loss and exercise, although several promising medications are on the horizon. In this article we discuss the etiology, pathogenesis and diagnosis of nonalcoholic fatty liver disease as well as approaches to its management.
BACKGROUND & AIMS: Long-term ursodeoxycholic acid (UDCA) therapy slows the progression of primary biliary cirrhosis. This study examined the effect of UDCA therapy on survival free of liver ...transplantation in a large group of patients.
METHODS: Data from three clinical trials were combined in which patients with primary biliary cirrhosis were randomly assigned to receive UDCA (n = 273) or placebo (n = 275). After 2 years, patients from French and Canadian studies received UDCA for up to 2 years. Patients from the American study remained on their assigned treatment for up to 4 years.
RESULTS: Survival free of liver transplantation was significantly improved in the patients treated with UDCA compared with the patients originally assigned to placebo (P < 0.001; relative risk, 1.9; 95% confidence interval, 1.3-2.8). Subgroup analyses showed that survival free of liver transplantation was significantly improved in medium- and high-risk groups (serum bilirubin level, 1.4 to 3.5 or > 3.5 mg/dL; P < 0.0001 and P < 0.03, respectively) and histological stage IV subgroup (P < 0.01).
CONCLUSIONS: Long-term UDCA therapy improves survival free of liver transplantation in patients with moderate or severe disease. An effect in patients with mild disease is probably not found because they do not progress to end-stage disease in 4 years. (Gastroenterology 1997 Sep;113(3):884-90)
Some studies have suggested that ursodeoxycholic acid (UDCA) may have a chemopreventive effect on the development of colorectal neoplasia in patients with ulcerative colitis (UC) and primary ...sclerosing cholangitis (PSC). We examined the effects of high-dose (28-30 mg/kg/day) UDCA on the development of colorectal neoplasia in patients with UC and PSC.
Patients with UC and PSC enrolled in a prior, multicenter randomized placebo-controlled trial of high-dose UDCA were evaluated for the development of colorectal neoplasia. Patients with UC and PSC who received UDCA were compared with those who received placebo. We reviewed the pathology and colonoscopy reports for the development of low-grade or high-grade dysplasia or colorectal cancer.
Fifty-six subjects were followed for a total of 235 patient years. Baseline characteristics (including duration of PSC and UC, medications, patient age, family history of colorectal cancer, and smoking status) were similar for both the groups. Patients who received high-dose UDCA had a significantly higher risk of developing colorectal neoplasia (dysplasia and cancer) during the study compared with those who received placebo (hazard ratio: 4.44, 95% confidence interval: 1.30-20.10, P=0.02).
Long-term use of high-dose UDCA is associated with an increased risk of colorectal neoplasia in patients with UC and PSC.
Based on animal studies and pilot studies in humans, betaine, a methyl donor for the remethylation of homocysteine, may be a therapeutic agent for nonalcoholic steatohepatitis (NASH). We evaluated ...the safety and efficacy of betaine for patients with NASH and whether betaine positively modified factors postulated to be “second hits” and underlying mechanisms of NASH. We conducted a randomized placebo‐control study of 55 patients with biopsy‐proven NASH who received either oral betaine (20 g daily) or placebo for 12 months. Pre‐ and posttreatment variables were analyzed using the paired t test or Wilcoxon rank test. Treatment groups were comparable at baseline. Of the 35 patients (17 betaine, 18 placebo) who completed the study, 34 patients (16 betaine, 18 placebo) underwent posttreatment liver biopsy. Patients randomized to betaine had a decrease in steatosis grade. No intra‐ or intergroup differences or changes in nonalcoholic fatty liver disease activity score or fibrosis stage were noted. Elevations of insulin, glucose, and proinflammatory cytokines and the reduced antioxidant status noted in NASH patients did not improve with betaine therapy. The antiinflammatory agent adiponectin was significantly reduced in both groups and did not change with therapy. Lastly, S‐adenosylhomocysteine was approximately twice normal and was not reduced by betaine therapy. Conclusion: Compared to placebo, betaine improved hepatic steatosis and may protect against worsening steatosis. High‐dose betaine supplementation failed to reduce S‐adenosylhomocysteine and did not positively affect any of the second hit mechanisms postulated to contribute to NASH that we studied. Although betaine has been proven effective in treating hepatic steatosis in several animal models, translating novel therapeutic options noted in animal studies to humans with NASH will prove challenging. (HEPATOLOGY 2009.)
Primary biliary cirrhosis Talwalkar, Jayant A; Lindor, Keith D
The Lancet (British edition),
07/2003, Letnik:
362, Številka:
9377
Journal Article
Recenzirano
Primary biliary cirrhosis is a chronic cholestatic liver disease of adults. This disorder is characterised histologically by chronic non-suppurative destruction of interlobular bile ducts leading to ...advanced fibrosis, cirrhosis, and liver failure. The precise aetiopathogenesis of primary biliary cirrhosis remains unknown, although dysregulation of the immune system and genetic susceptibility both seem to be important. Affected patients are typically middle-aged women with abnormal serum concentrations of alkaline phosphatase. Presence of antimitochondrial antibody in serum is almost diagnostic of the disorder. Identification of primary biliary cirrhosis is important, because effective treatment with ursodeoxycholic acid has been shown to halt disease progression and improve survival without need for liver transplantation. However, therapeutic options for disease-related complications—including fatigue and metabolic bone disease—remain unavailable. Mathematical models have been developed that accurately predict the natural history of primary biliary cirrhosis in individuals. Despite advances in understanding of the disease, it remains one of the major indications for liver transplantation worldwide.
Primary biliary cirrhosis (PBC) is an autoimmune disease of unknown etiology, often associated with other autoimmune conditions. Controlled studies have so far provided conflicting data on risk ...factors and comorbidity rates in PBC. We enrolled patients with PBC (n = 1032) from 23 tertiary referral centers for liver diseases in the United States and random-digit-dialed controls (n = 1041) matched for sex, age, race, and geographical location. Patients and controls were administered a modified version of the US National Health and Nutrition Examination Study (NHANES III) questionnaire by trained personnel to evaluate associations between PBC and social, demographic, personal and family medical histories, lifestyle, and reproductive factors and the rates of comorbidity in affected individuals. Data indicate that having a first-degree relative with PBC (adjusted odds ratio AOR 10.736; 95% confidence interval 4.227-27.268), history of urinary tract infections (AOR 1.511, 95% CI 1.192-1.915), past smoking (AOR 1.569, 95% CI 1.292-1.905), or use of hormone replacement therapies (AOR 1.548, 95% CI 1.273-1.882) were significantly associated with increased risk of PBC. The frequent use of nail polish slightly increased the risk of having PBC. Other autoimmune diseases were found in 32% of cases and 13% of controls (P<0.0001). In conclusion, environmental factors, possibly including infectious agents through urinary tract infections or chemicals contained in cigarette smoke, may induce PBC in genetically susceptible individuals. Exogenous estrogens may also contribute to explain the female predominance of the disease.
The pathogenesis of nonalcoholic steatohepatitis (NASH) remains poorly understood. Although apoptosis is a common mechanism of liver injury, the extent and clinical significance of apoptosis in NASH ...has not been examined. Thus, the aims of this study were to quantify hepatocyte apoptosis in NASH, correlate it with disease severity, and identify possible mechanisms of apoptosis induction.
Hepatocyte apoptosis was assessed in NASH, simple steatosis, alcoholic hepatitis, and controls without liver disease using the TUNEL assay and immunohistochemistry for activated caspases 3 and 7. Liver specimens were also graded according to the magnitude of inflammation and fibrosis.
TUNEL-positive cells were significantly increased in liver biopsy specimens from patients with NASH compared with simple steatosis and controls. Unexpectedly, TUNEL-positive cells were also greater in NASH vs. alcoholic hepatitis. Immunohistochemistry demonstrated active caspases 3 and 7 in NASH specimens, confirming the occurrence of apoptosis in this disease. A positive correlation was observed between hepatocyte apoptosis and hepatic fibrosis and inflammatory activity, respectively. The Fas receptor was strongly expressed in hepatocytes in liver specimens from NASH patients as compared with controls.
Hepatocyte apoptosis is significantly increased in patients with NASH and correlates with disease severity, suggesting that antiapoptotic therapy may be useful in this syndrome.
Non-alcoholic fatty liver disease ANGULO, PAUL; LINDOR, KEITH D
Journal of gastroenterology and hepatology,
February 2002, Letnik:
17, Številka:
s1
Journal Article, Conference Proceeding
Recenzirano
Non‐alcoholic fatty liver disease (NAFLD) is a chronic liver disease that affects a high proportion of the world’s population. Insulin resistance and oxidative stress play a critical role in the ...pathogenesis of NAFLD. Clinical, biochemical and imaging studies are of value in the diagnostic evaluation of patients with NAFLD, but liver biopsy remains the most sensitive and specific means of providing important diagnostic and prognostic information. Simple steatosis has the best prognosis within the spectrum of NAFLD, but NAFLD has the potential to progress to steatohepatitis, fibrosis and even cirrhosis. No effective medical therapy is currently available for all patients with NAFLD. In patients with diabetes mellitus and hyperlipidemia, appropriate metabolic control is always recommended, but rarely effective in resolving the liver disease. Weight reduction, when achieved and sustained, may improve the liver disease, although the results with weight loss have been inconsistent. Pharmacological therapy aimed at the underlying liver disease holds promise. Several medications with different mechanisms of action and potential benefit are currently being evaluated in clinical trials. Liver transplantation is a life‐extending therapeutic alternative for patients with end‐stage NAFLD, but NAFLD may recur after liver transplantation.
No effective medical therapy is available for all patients with nonalcoholic steatohepatitis (NASH). Ursodeoxycholic acid (UDCA) has been suggested to be of benefit based on open label clinical ...studies. We randomized 166 patients with liver biopsy–proven NASH to receive between 13 and 15 mg/kg/d of UDCA or placebo for 2 years. End points included changes in liver test results and liver histology at 2 years of therapy. The treatment groups were comparable at entry with regard to age, gender, risk factors for NASH, serum liver biochemistries, and baseline liver histology. A total of 126 patients completed 2 years of therapy. Pre‐ and posttreatment liver biopsies were available in 107 patients for review at the end of the study. UDCA was well tolerated and body weight was stable during the study duration. Serum liver biochemistries were stable or improved in both the UDCA and placebo‐treated groups. Changes in the degree of steatosis, necroinflammation, or fibrosis that occurred with therapy were not significantly different between the UDCA and placebo groups. In conclusion, 2 years of therapy with UDCA at a dose of 13 to 15 mg/kg/d, although safe and well tolerated, is not better than placebo for patients with NASH. (HEPATOLOGY 2004;39:770–778.)
Cholangiocarcinoma (CCA) is a dreaded complication of primary sclerosing cholangitis (PSC); however, marked variability in the incidence of CCA in PSC is reported. Furthermore, limited information ...exists on risk factors for the development of CCA in PSC. The aim of this study was to determine the incidence of CCA in patients with PSC and to evaluate baseline risk factors for the later development of CCA. From a previous study of the natural history of PSC, we identified 161 patients with PSC who did not have CCA at study entry. Patients were followed until a diagnosis of CCA was established, liver transplantation was performed, or death occurred. Patients were followed for a median of 11.5 yr (interquartile range 4.0-16.1 yr). Fifty-nine patients (36.6%) died, 50 patients (31.1%) underwent liver transplantation, and 11 patients (6.8%) developed CCA. The rate of CCA developing was approximately 0.6% per year. Compared to the incidence rates of CCA in the general population, the relative risk of CCA in PSC was significantly increased (RR = 1,560; 95%CI = 780, 2,793; p < 0.0001). On univariate analysis, a history of variceal bleeding (p < 0.001), proctocolectomy (p= 0.01), and lack of symptoms (p= 0.02) were significant risk factors for CCA with the Mayo Risk Score being marginally significant (p= 0.051). Multivariate analysis determined only variceal bleeding to be a significant risk factor for CCA (RR 24.2; 95%CI: 3.3-67.1). No association was found between the duration of PSC and the incidence of CCA. In conclusion, approximately 7% of PSC patients later developed CCA over a mean follow-up of 11.5 yr, which is dramatically higher than the rates in the general population. Variceal bleeding is a major risk factor for the later development of CCA.
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