非酒精性脂性肝炎的中西医诊断与治疗进展

1980年Ludwig及其同事曾描述了无饮酒病史，肝活检有如酒精性肝炎病变的肝病，并命名此病为非酒精性脂性肝炎(Nonalcoholic Steatohepatitis，NASH)。其特点为病者缺乏饮酒病史，肝脏活检的组织病理学表现为肝细胞脂肪变性，肝小叶混合性炎症细胞浸润，肝窦周围纤维化或肝硬化，偶见Mallory透明小体，难与酒精性肝炎的组织学变化相鉴别。NASH可进展为威胁生命的肝病，因而对不明原因慢性肝酶升高或息有慢性肝病，特别是伴有肥胖症，糖尿病及高脂血症的病者，应考虑NASH的诊断。

非酒精性脂肪性肝病相关肝癌发病机制的研究进展

非酒精性脂肪性肝病（NAFLD）是临床上最常见的慢性肝脏疾病之一，可从单纯性脂肪肝进展为非酒精性脂肪性肝炎、肝纤维化和肝硬化，最终可发展为肝细胞肝癌（HCC）。尽管研究表明，许多细胞信号通路、基因及细胞因子等参与NAFLD相关的HCC的发生发展，但是其发病的具体分子机制尚不清楚。现结合国内外近年的文献报道，对NAFLD相关的HCC的流行病学及发病机制做一综述。

Olive oil consumption and non-alcoholic fatty liver disease

The clinical implications of non-alcoholic fatty liver diseases(NAFLD)derive from their potential to progress to fibrosis and cirrhosis.Inappropriate dietary fat intake,excessive intake of soft drinks,insulin resistance and increased oxidative stress results in increased free fatty acid delivery to the liver and increased hepatic triglyceride(TG)accumulation.An olive oil-rich diet decreases accumulation of TGs in the liver,improves postprandial TGs,glucose and glucagonlike peptide-1 responses in insulin-resistant subjects, and upregulates glucose transporter-2 expression in the liver.The principal mechanisms include:decreased nuclear factor-kappaB activation,decreased lowdensity lipoprotein oxidation,and improved insulin resistance by reduced production of inflammatory cytokines(tumor necrosis factor,interleukin-6)and improvement of jun N-terminal kinase-mediated phosphorylation of insulin receptor substrate-1.The beneficial effect of the Mediterranean diet is derived from monounsaturated fatty acids,mainly from olive oil.In this review,we describe the dietary sources of the monounsaturated fatty acids,the composition of olive oil,dietary fats and their relationship to insulin resistance and postprandial lipid and glucose responses in non-alcoholic steatohepatitis,clinical and experimental studies that assess the relationship between olive oil and NAFLD,and the mechanism by which olive oil ameliorates fatty liver,and we discuss future perspectives.

Angiotensin-receptor blockers as therapy for mild-to-moderate hypertension-associated non-alcoholic steatohepatitis

AIM： TO evaluate insulin resistance, cytolysis and nonalcoholic steatohepatitis （NASH） score （NAS） using the Kleiner and Brunt criteria in 54 patients with NASH and mild-to-moderate hypertension, treated with telmisartan vs valsartan for 20 mo. METHODS： All patients met the NCEP-ATP Ⅲ criteria for metabolic syndrome. Histology confirmed steatohepatitis, defined as a NAS greater than five up to 3 wk prior inclusion, using the current criteria. Patients with viral hepatitis, chronic alcohol intake, drug abuse or other significant immune or metabolic hepatic pathology were excluded. Subjects were randomly assigned either to the valsartan （V） group （standard dose 80 mg o.d., n = 26）, or to the telmisartan （T） group （standard dose 20 mg o.d., n = 28）. Treatment had to be taken daily at the same hour with no concomitant medication or alcohol consumption allowed. Neither the patient nor the medical staff was aware of treatment group allocation. Paired liver biopsies obtained at inclusion （visit 1） and end of treatment （EOT） were assessed by a single blinded pathologist, not aware of patient or treatment group. Blood pressure, BMI, ALT, AST, HOMA-IR, plasma triglycerides （TG） and total cholesterol （TC） were evaluated at inclusion and every 4 mo until EOT （visit 6）. RESULTS： At EOT we noticed a significant decrease in ALT levels vs inclusion in all patients and this decrease did not differ significantly in group T vs group V. HOMA-IR significantly decreased at EOT vs inclusion in all patients but in group T, the mean HOMA-IR decrease per month was higher than in group V. NAS significantly diminished at EOT in all patients with a higher decrease in group T vs group V. CONCLUSION： Angiotensin receptor blockers seem to be efficient in hypertension-associated NASH. Telmisartan showed a higher efficacy regarding insulin resistance and histology, perhaps because of its specific PPAR-gamma ligand effect.

Liver histology according to the presence of metabolic syndrome in nonalcoholic fatty liver disease cases

AIM:To investigate the histologic features of the liver in nonalcoholic fatty liver disease (NAFLD) cases according to the presence of metabolic syndrome or its individual components. METHODS:We enrolled 81 patients (40 male,41 fe-male) who were diagnosed with fatty liver by ultraso-nographic scan and fulfi lled the inclusion criteria. First anamnesis,anthropometric,clinical,laboratory and imaging features of all participants were recorded and then liver biopsy was performed after gaining consent from patients. Diagnosis of metabolic syndrome was dependent on patients having 3 or more out of 5 risk criteria defined by the WHO. Biopsy specimens were assessed according to Brunt et al's classification. RESULTS:Sixty-nine of the 81 patients had nonalco-holic steatohepatitis (NASH),11 had simple fatty liver and 1 had cirrhosis according to histologic evaluation. Comparisons were made between two groups of NASH patients,those with and without metabolic syndrome. We did not detect statistically significant differences in liver histology between NASH patients with and wit-hout metabolic syndrome. CONCLUSION:NASH can progress without metabolic risk factors or the presence of metabolic syndrome.

A rabbit model of pediatric nonalcoholic steatohepatitis: The role of adiponectin

AIM： To create a rabbit model of pediatric nonalcoholic steatohepatitis （NASH） and to evaluate the role of adiponectin in the process. METHODS： Thirty-two specific pathogen-free male New Zealand rabbits were divided randomly into three groups： （1） the normal control group （n = 10） was fed with standard diet for 12 wk; （2） the model group A （n = 11）; and （3） model group B （n = 11） were fed with a highfat diet （standard diet ＋ 10% lard ＋ 2% cholesterol） for 8 and 12 wk, respectively. Hepatic histological changes were observed and biochemical parameters as well as serum levels of adiponectin, interleukin （IL）-6, IL-10 and tumor necrosis factor （TNF）-α were measured. RESULTS： Typical histological hepatic lesions of NASH were observed in both model groups described as liver steatosis, liver inflammatory infiltration, cytologic ballooning, perisinusoidal fibrosis and overall fibrosis. Compared with the normal control group, there were significant increases in model groups A and B in weight gain （1097.2 ± 72.3, 1360.5± 107.6 vs 928.0 ±58.1, P 〈 0.05, P 〈 0.01）, liver weight （93.81±6.64, 104.6±4.42 vs 54.4±1.71, P 〈 0.01）, Lg （ALT） （1.9±0.29, 1.84± 0.28 vs 1.60±0.17, P 〈 0.01）, and Lg （TG） （1.03 ±0.24, 1.16 ±0.33 vs 0.00 ±0.16, P 〈 0.01）. Weight gain was much more in model group B than in model group A （1360.5± 107.6 vs 1097.2 ±72.3, P 〈 0.05）. But, there was no significant difference between the two groups concerning the other indexes. Pro-inflammatory cytokines （IL-6 and TNF-α） increased in model group B compared with that of control and model group A （IL-6：1.86±0.21 vs 1.41 ±0.33, 1.38± 0.42, P 〈 0.01; TNF-α： 1.18±0.07 vs 0.66 ±0.08, 0.86 ±0.43, P 〈 0.01, P 〈 0.05）, whereas serum adiponectin and IL-10 decreased in model groups compared with that in the control （adiponectin： A： 21.87±4.84 and B： 21.48 ±4.60 vs 27.36 ±7.29, P 〈 0.05. IL-10： A： 1.72± 0.38 and B： 1.83 ±0.39 vs 2.26±0.24, P 〈 0.01）. Lg （TC） and the degree of liver fatty infiltration was an independent determinant of serum adiponectin level analyzed by stepwise multiple regressions, resulting in 29.4% of variances. CONCLUSION： This rabbit model produces the key features of pediatric NASH and may provide a realistic model for future studies. Adiponectin level partially reflects the severity of liver steatosis, but not the degree of liver inflammation.

Hyperferritinemia is a risk factor for steatosis in chronic liver disease

AIM: To investigate the relationship between ferritin and steatosis in patients with chronically abnormal liver function tests (LFTs) and high ferritin level. METHODS: One hundred and twenty-four consecutive patients with hyperferritinemia (male > 300 ng/mL, female > 200 ng/mL) were evaluated; clinical, biochemical and serological data, iron status parameters, HFE gene mutations and homeostasis model assessment score were obtained. Steatosis was graded by ultrasound as absent or present. Histology was available in 53 patients only. RESULTS: Mean level of ferritin was 881 ± 77 ng/mL in men and 549 ± 82 ng/mL in women. The diagnosis was chronic hepatitis C in 53 (42.7%), non-alcoholic fatty liver disease/non-alcoholic steatohepatitis in 57 (45.9%), and cryptogenic liver damage in 14 (11.3%). None was diagnosed as hereditary hemochromatosis (HH). Hepatic siderosis on liver biopsy was present in 17 of 54 (32%) patients; grade 1 in eight and grade 2 in nine. Overall, 92 patients (74.2%) had steatosis. By logistic regression, ferritin and γ-glutamyltransferase were independent predictors of steatosis. Ferritin levels were signifi cantly related to low platelet count, steatosis and hepatitis C virus infection. CONCLUSION: In a non-obese cohort of non-alcoholic patients with chronically abnormal LFTs without HH, high serum ferritin level is a risk factor for steatosis.

Iron overload and cofactors with special reference to alcohol,hepatitis C virus infection and steatosis/insulin resistance

There are several cofactors which affect body iron metabolism and accelerate iron overload. Alcohol and hepatic viral infections are the most typical examples for clarifying the role of cofactors in iron overload. In these conditions, iron is deposited in hepatocytes and Kupffer cells and reactive oxygen species （ROS） produced through Fenton reaction have key role to facilitate cellular uptake of transferrin-bound iron. Furthermore, hepcidin, antimicrobial peptide produced mainly in the liver is also responsible for intestinal iron absorption and reticuloendothelial iron release. In patients with ceruloplasmin deficiency, anemia and secondary iron overload in liver and neurodegeneration are reported. Furthermore, there is accumulating evidence that fatty acid accumulation without alcohol and obesity itself modifies iron overload states. Ineffective erythropoiesis is also an important factor to accelerate iron overload, which is associated with diseases such as thalassemia and myelodysplastic syndrome. When this condition persists, the dietary iron absorption is increased due to the increment of bone marrow erythropoiesis and tissue iron overload will thereafter occurs. In porphyria cutanea tarda, iron is secondarily accumulated in the liver.

Non-alcoholic steatohepatitis with normal aminotransferase values

AIM： To investigate the aspects of liver histology in patients with non-alcoholic steatohepatitis （NASH） who had normal aminotransferase levels. METHODS： Thirty-four patients diagnosed with liver steatosis by ultrasonographic examination participated in the study. We compared all non- alcoholic fatty liver disease and NASH cases, according to aminotransferase level, aspartate aminotransferase （AST）/alanine aminotransferase （ALT） ratio and presence of metabolic syndrome. RESULTS： Sixteen of 25 patients with high aminotransferase levels were diagnosed with NASH and nine with simple fatty liver according to liver histology. Among the nine patients with normal aminotransferase levels, seven had NASH and two had simple fatty liver. The patients with normal and high liver enzyme levels had almost the same prevalence of NASH and metabolic syndrome. Liver histology did not reveal any difference according to aminotransferase levels and AST/ALT ratio. CONCLUSION： Aminotransferase levels and AST/AIT ratio do not seem to be reliable predictors for NASH. Despite numerous non-invasive biomarkers, all patients with fatty liver should undergo liver biopsy.