Mikihiro Tsutsumi

Genetic polymorphisms of cytochrome P4502E1 related to the development of alcoholic liver disease

Abstract Background/Aims: Because heavy drinkers do not always develop alcoholic liver disease (ALD), genetic factors may be involved. Cytochrome P4502E1 is the main enzyme that oxidizes ethanol in the non-alcohol dehydrogenase pathway. Recently, the presence of genetic polymorphisms of this enzyme was confirmed. In the present study, the genotypes of P4502E1 were analyzed in patients with or without ALD. Methods: After extraction of DNA from white blood cells, genotypes of P4502E1 were determined by restriction fragment length polymorphisms using two endonucleases. The genotypes were separated into three types: type A, type C (homozygous for the c1 or c2 gene), and type B (heterozygous for both genes). Results: In 50 patients with ALD, the prevalence of type A was 16% and that of the c2 gene was 84%. The genotypes in 10 heavy drinkers without ALD were all type A. In 34 patients with non-alcoholic liver disease and in 88 patients without hepatobiliary disease, the prevalence of type A was 65% and 71%, respectively, indicating a significantly higher prevalence of the c2 gene in ALD. In healthy nonalcoholics, the prevalence of type A was 62%–68%. Conclusions: These results suggest that polymorphisms of P4502E1 may be related to the development of ALD.

Biochemical markers of chronic alcoholism

Usefulness of several biochemical markers for the monitoring of chronic alcoholism were studied. Among generally used markers, only gamma-GTP showed a significant difference between alcoholic and non-alcoholic liver diseases. Serum glutamate dehydrogenase (GDH) activity was significantly high in alcoholic liver disease. When the ratios of GDH to ornithine carbamyl transferase (OCT) were calculated, differences between alcoholic and non-alcoholic liver diseases became clearer without overlapping of any value. Serum desialo-transferrin was found in about 60% of the alcoholics, and disappeared by abstinence. Microheterogeneity of serum protein was also found in other glycoproteins. Serum prealbumin level was significantly high in alcoholics without severe liver disease. Acetaldehyde dehydrogenase (ALDH) activity of erythrocytes was significantly low in alcoholics, and gradually increased after abstinence. These results indicate that microheterogeneity of glycoproteins, serum prealbumin level and erythrocyte ALDH activity are good markers of alcohol abuse, and serum GDH/OCT ratio is the most sensitive marker of alcoholic liver injury. Serum gamma-GTP activity is a good marker of both conditions.

Full-length sequence of the genome of hepatitis C virus type 3a: comparative study with different genotypes

Hepatitis C virus (HCV) type K3a (type 3a), which represents a minor genotype in Europe, the U.S.A. and Asia, appears to be significantly distributed throughout Australia and Brazil. We amplified the HCV-K3a/650 genome by reverse transcription polymerase chain reaction in ten overlapping fragments and determined the nucleotide sequences. The total sequence was 9454 bases in length and contained an open reading frame of 3021 amino acids, which is 10 or 11 amino acids longer than in HCV type 1 and 12 amino acids shorter than the sequence of type 2. These differences were due to the different lengths of both the putative envelope protein E2 and the NS5A regions, whose nucleotide lengths differ between types 1 and 2 also. Phylogenetic analysis of the putative core region and a portion of NS5B encoding the Gly-Asp-Asp motif indicated that HCV-K3a closely matched the corresponding type 3a group. The deletion and addition of amino acids in both E2 and NS5A may be associated with their pathobiological features.

National survey of alcoholic liver disease in Japan (1968–91)

National surveys of alcoholic liver disease (ALD) in Japan were performed in 1978 and 1985 by a previous Japanese study group for ALD (the Takeuchi group). In the present study, a subsequent nationwide survey of ALD in Japan was conducted from 1986 to 1991 and the results compared with the previous studies. In order to clarify the aetiological relationship between hepatitis C virus (HCV) infection and ALD, results were also analysed according to new diagnostic criteria for ALD proposed by the current ALD study group (the Takada group).

Expression of hyaluronic acid in N-nitrosodimethylamine induced hepatic fibrosis in rats

Hyaluronic acid (HA) plays prominent role in the pathogenesis of liver fibrosis. The mechanism of increased serum and liver HA during hepatic fibrosis was studied in rats. Liver injury was induced by intraperitoneal injections of N-nitrosodimethylamine (NDMA) for 7 consecutive days. A group of animals were sacrificed on everyday during injection and also on days 14 and 21 after the start of NDMA administration. The alpha-smooth muscle actin (alpha-SMA) was stained as a marker for activated stellate cells. Liver HA was studied by histochemical methods and serum HA was monitored by HA binding protein assay. CD44 was stained immunohistochemically. After the start of NDMA administration, necrosis was initiated on day 3 and massive necrosis was observed on days 5 and 7. Fibrosis was developed on day 14 and early cirrhosis was present on day 21. Staining of alpha-SMA demonstrated activated stellate cells from day 3 onwards. Serum HA peaked on day 7 and reduced afterwards. Serial liver sections stained for HA revealed excessive accumulation of HA during NDMA administration. On days 14 and 21, alpha-SMA and HA staining was remarkable in fibrotic and cirrhotic areas. CD44 staining was negative except during necrosis. It is concluded that the early elevation of serum HA is due to the increased synthesis and simultaneous release from the necrotic liver. In latter stages the increase of both serum and liver HA is contributed by the increased synthesis by the activated stellate cells and reduced clearance by the impaired sinusoidal endothelial cells.

Nutrition and exercise in the management of liver cirrhosis

Liver cirrhosis (LC) patients often have protein-energy malnutrition (PEM) and decreased physical activity. These conditions often lead to sarcopenia, which is the loss of skeletal muscle volume and increased muscle weakness. Recent studies have demonstrated that PEM and sarcopenia are predictors for poor survival in LC patients. Nutrition and exercise management can improve PEM and sarcopenia in those patients. Nutrition management includes sufficient dietary intake and improved nutrient metabolism. With the current high prevalence of obesity, the number of obese LC patients has increased, and restriction of excessive caloric intake without the exacerbation of impaired nutrient metabolism is required for such patients. Branched chain amino acids are good candidates for supplemental nutrients for both obese and non-obese LC patients. Exercise management can increase skeletal muscle volume and strength and improve insulin resistance; however, nutritional status and LC complications should be assessed before an exercise management regimen is implemented in LC patients. The establishment of optimal exercise regimens for LC patients is currently required. In this review, we describe nutritional status and its clinical impact on the outcomes of LC patients and discuss general nutrition and exercise management in LC patients.

Relationship between hepatocellular carcinoma and subtypes of hepatitis C virus: a nationwide analysis.

Although hepatitis C virus (HCV) has now been classified into several subtypes, the clinical significance of HCV subtypes is not well known. Typing of HCV is now routinely performed in Japan. In the present study, HCV subtypes in hepatocellular carcinoma (HCC) patients were analysed from nationwide data collected in Japan using a standard questionnaire. Answers to the questionnaire concerning HCV subtypes in patients with chronic hepatitis (CH), liver cirrhosis (LC) and HCC were obtained from 14 hospitals. The prevalence of the 1b‐related subtype, which includes the mixed subtype of 1b and 2a or 2b, in patients with LC and HCC in each hospital was higher than in patients with CH, with few exceptions. However, the differences were not statistically significant because of the small number of patients in each hospital. In summarized data from all 14 hospitals, the 1b‐related subtype was found in 1370 of 1922 patients with CH (71.2%). In 356 LC and 426 HCC patients, the prevalence of the 1b‐related subtype was 79.8 and 80.5%, respectively. The prevalence of the 1b‐related subtype in patients with LC and HCC was significantly higher than in patients with CH. There was no significant difference between the prevalence of the 1b‐related subtype in patients with HCC and LC. These results indicate that the oncogenic activity of subtype 1b, although not yet clearly characterized, may be stronger than subtypes 2a and 2b.

Association between functional promoter polymorphisms of macrophage migration inhibitory factor (MIF) gene and ulcerative colitis in Japan.

Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. Two functional polymorphisms were identified in the promoter region of MIF gene. We attempted to clarify the associations between these polymorphisms and ulcerative colitis (UC). The study was performed in 111 patients with UC and 209 subjects without UC. We employed the PCR-SSCP method to detect gene polymorphisms. Overall, 5/5-CATT genotype was a decreased risk for the development of UC (OR, 0.51; 95% CI, 0.26-0.99). In addition, 7/7-CATT genotype was significantly associated with chronic continuous phenotype and distal colitis phenotype (OR, 5.49; 95% CI, 1.19-25.3, and OR, 6.10; 95% CI, 1.32-28.2, respectively), whereas 5/5-CATT genotype had an inhibitory effect on the development of UC after 20years of age (OR, 0.33; 95% CI, 0.14-0.82). On the other hand, G-173C polymorphism did not affect the susceptibility to and the phenotypes of UC. Our results suggested that tetranucleotide CATT repeat of MIF gene promoter may be associated with the development of UC and the severity of inflammation in patients with UC.

Characteristic features of alcoholic liver disease in Japan: A review

SummaryThe characteristics of alcoholic liver disease (ALD) in Japanese patients were reviewed and compared with those in Western countries. From the study in Japanese cases, it became clear that alcoholic fibrosis and chronic hepatitis induced by alcohol were types of ALD other than the traditional 3 types. Liver injury in Japanese cases was clearly milder than that in American cases. In American cases, the injury may be fully developed, because of greater alcohol and fat intake. This may be one reason why the two above types of ALD have not been mentioned in the literature of Western countries. In Japanese patients, hepatitis C virus (HCV) infection is not related to alcoholic fibrosis and alcoholic hepatitis. On the other hand, the prevalence of HCV markers was high in chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC) patients. Alcoholic hepatitis and chronic hepatitis are the high risk groups for the development of cirrhosis and the chronic hepatitis group is at high risk for the development of HCC. Although the risk is low in alcoholic fibrosis, some patients also develop cirrhosis. About half of the cases of cirrhosis may develop from alcoholic hepatitis and alcoholic fibrosis, and the remaining half cases may develop from chronic hepatitis. Over 80% of HCC cases may develop from chronic hepatitis in Japan. Chronic alcoholism enhanced the development of HCV-related HCC. Recent increase of HCC in alcoholic cirrhosis in Japan may be related to the increase of alcohol consumption, the increase of blood transfusions, and longer survival of cirrhosis patients.

Serum Osteopontin Predicts Degree of Hepatic Fibrosis and Serves as a Biomarker in Patients with Hepatitis C Virus Infection

Background & Aims Osteopontin (OPN) is a matricellular protein that upregulates during pathogenesis of hepatic fibrosis. The present study was aimed to evaluate whether serum OPN could be used as a biomarker to assess the degree of hepatic fibrosis in patients with hepatitis C virus (HCV) infection. Methods Needle biopsy was performed on HCV patients and scored as zero fibrosis (F0), mild fibrosis (F1), moderate fibrosis (F2), severe fibrosis (F3) and liver cirrhosis (F4) based on Masson’s trichrome and α-smooth muscle actin (α-SMA) staining. Serum OPN levels were measured using ELISA and correlated with the degree of fibrosis. Furthermore, the OPN values were correlated and evaluated with platelets count, serum hyaluronic acid (HA), and collagen type IV and subjected to receiver operating characteristic (ROC) curve analysis. Results Serum OPN levels were remarkably increased from F0 through F4 in a progressive manner and the differences were significant (P < 0.001) between each group. The data were highly correlated with the degree of hepatic fibrosis. The ROC curve analysis depicted that serum OPN is an independent risk factor and an excellent biomarker and a prognostic index in HCV patients. Conclusions The results of the present study indicate that serum OPN levels reflect the degree of hepatic fibrosis and could be used as a biomarker to assess the stage of fibrosis in HCV patients which would help to reduce the number of liver biopsies. Furthermore, serum OPN serves as a prognostic index towards the progression of hepatic fibrosis to cirrhosis and hepatocellular carcinoma.