Meta-analysis of the diagnostic accuracy of serum type IV collagen 7S concentration for the staging of liver fibrosis in nonalcoholic fatty liver disease

AIM

We aimed to evaluate the diagnostic accuracy of the measurement of serum type IV collagen 7S (T4C7S) concentration for the staging of liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

A systematic search or published works was carried out using the PubMed, Cochrane Library, and Web of Science Core Collection databases for studies of the accuracy of serum T4C7S concentration for the staging of fibrosis using Fibrosis stage (F)0-4 in patients with NAFLD diagnosed by liver biopsy.

RESULTS

Nine articles describing 1475 participants with NAFLD were included. For fibrosis ≥F1, with n = 849, summary estimates of sensitivity of 0.79, specificity of 0.69, and area under the curve (AUC) of 0.80 were obtained using a median T7C4S cut-off value of 4.6 ng/ml. For fibrosis ≥F2, with n = 1,090, summary estimates of sensitivity of 0.78, specificity of 0.78, and AUC of 0.84 were obtained using a median cut-off value of 4.9 ng/ml. For fibrosis ≥F3, with n = 1311 participants and a median cut-off value of 5.4 ng/ml, a pooled sensitivity of 0.82, specificity of 0.81, and AUC of 0.83 were obtained. For fibrosis ≥F4, with n = 753 and a median cut-off value of 6.6 ng/ml, a pooled sensitivity of 0.85, specificity of 0.81, and AUC of 0.85 were obtained.

CONCLUSIONS

Serum T4C7S concentration was found to be an accurate method of staging liver fibrosis in patients with NAFLD.

Protective effect of SGL5213, a potent intestinal sodium-glucose cotransporter 1 inhibitor, in nonalcoholic fatty liver disease in mice

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic disease. SGL5213, which is minimally absorbed and is restricted to the intestinal tract, is a potent intestinal sodium-glucose cotransporter 1 (SGLT1) inhibitor. In this study, we investigated the protective effect of SGL5213 in a rodent model of NAFLD.

METHODS

Using a rodent model of NAFLD, we compared SGL5213 efficacy with miglitol, which is an α-glucosidase inhibitor. We used a high-fat and high-sucrose diet-induced NAFLD model.

RESULTS

SGL5213 and miglitol improved obesity, liver dysfunction, insulin resistance, and the NAFLD severity. To further investigate the effects of SGL5213, we analyzed the mRNA expression of genes involved in lipid metabolism, inflammation, and liver fibrosis, and cecal pH levels. SGL5213 and miglitol treatment significantly decreased mRNA expression of factors involved in inflammation and liver fibrosis. SGL5213 treatment significantly decreased cecal pH levels, which did not occur with miglitol.

CONCLUSIONS

SGL5213 had a protective effect on the pathogenesis of NAFLD in a rodent model. We considered that inhibiting glucose absorption and increasing glucose content in the gastrointestinal tract with SGL5213 might have contributed to the protective effect in NAFLD. SGL5213 is a promising therapeutic agent for NAFLD with obesity and insulin resistance.

MRI-Based Quantitative R2* Mapping at 3 Tesla Reflects Hepatic Iron Overload and Pathogenesis in Nonalcoholic Fatty Liver Disease Patients

BACKGROUND

The role of hepatic iron overload (HIO) in nonalcoholic fatty liver disease (NAFLD) pathogenesis has not been fully elucidated.

PURPOSE

This study aimed to investigate the effect of HIO and examine the diagnostic usefulness of magnetic resonance imaging (MRI)-based R2^* quantification in evaluating hepatic iron content (HIC) and pathological findings in NAFLD.

STUDY TYPE

Prospective and retrospective.

POPULATION

A prospective study of 168 patients (age, 57.2 ± 15.0; male/female, 80/88) and a retrospective validation study of 202 patients (age, 57.0 ± 14.4; male/female, 113/89) with liver-biopsy-confirmed NAFLD were performed.

FIELD STRENGTH/SEQUENCE

3 T; chemical-shift encoded multi-echo gradient echo.

ASSESSMENT

Using liver tissues obtained by liver biopsy, HIC was prospectively evaluated in 168 patients by atomic absorption spectrometry. Diagnostic accuracies of HIC and R2^* for grading hepatic inflammation plus ballooning (HIB) as an indicator of NAFLD activity were assessed.

STATISTICAL TESTS

Student's t-test and analysis of variance (ANOVA) with Scheffe's multiple testing correction for univariate comparisons; multivariate logistic analysis. P-value less than 0.05 is statistically significant.

RESULTS

HIC was significantly correlated with HIB grades (r = 0.407). R2^* was significantly correlated with HIC (r = 0.557) and HIB grades (r = 0.569). R2^* mapped an area under the receiver operating characteristic (AUROC; 0.774) for HIC ≥808 ng/mL (median value) with cutoff value of 62.5 s^-1 . In addition, R2^* mapped AUROC of HIB for grades ≥3 was 0.799 with cutoff value of 58.5 s^-1 . When R2^* was <62.5 s^-1 , R2^* correlated weakly with HIC (r = 0.372) as it was affected by fat deposition and did not correlate with HIB grades (P = 0.052). Conversely, when R2^* was ≥62.5 s^-1 , a significant correlation of R2^* with HIC (r = 0.556) and with HIB grades was observed (P < 0.0001) with being less affected by fat deposition.

DATA CONCLUSION

R2^*  ≥ 62.5 s^-1 is a promising modality for non-invasive diagnosis of clinically important high grades (≥3) of HIB associated with increased HIC.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 2.

Lubiprostone in patients with non-alcoholic fatty liver disease: a randomised, double-blind, placebo-controlled, phase 2a trial

BACKGROUND

The laxative drug lubiprostone improves intestinal permeability in healthy volunteers. We aimed to assess efficacy and safety of lubiprostone in patients with non-alcoholic fatty liver disease (NAFLD) with constipation via attenuation of intestinal permeability.

METHODS

This randomised, double-blind, placebo-controlled, phase 2a study in Yokohama City University Hospital, Japan, recruited patients (aged 20-85 years) with NAFLD and constipation, alanine aminotransferase (ALT) at least 40 U/L, liver stiffness (≤6·7 kPa), and hepatic fat fraction at least 5·2% when assessed by MRI-proton density fat fraction. Eligible patients were randomly assigned (11:10:9) by a computer-based system and stratified by age and sex to receive 24 μg lubiprostone, 12 μg lubiprostone, or placebo, orally, once per day for 12 weeks. The primary endpoint was the absolute changes in ALT at 12 weeks. Efficacy analysis was done by intention to treat. Safety was assessed in all treated patients. This trial was registered with University Hospital Medical Information Network Clinical Trials Registry (UMIN000026635).

FINDINGS

Between March 24, 2017, and April 3, 2018, we screened 288 patients, of whom 150 (52%) were randomly assigned to treatment: 55 patients were assigned to receive 24 μg lubiprostone, 50 to receive 12 μg lubiprostone, and 45 to receive placebo. A greater decrease in the absolute ALT levels from baseline to 12 weeks was seen in the 24 μg lubiprostone group (mean -13 U/L [SD 19]) than in the placebo group (1 U/L [24]; mean difference -15 U/L [95% CI -23 to -6], p=0·0007) and in the 12 μg lubiprostone group (-12 U/L [21]) than in the placebo group (mean difference -13 U/L [-22 to -5], p=0·0023). 18 (33%) of 55 patients in the 24 μg group had at least one adverse event, as did three (6%) of 47 patients in the 12 μg group and three (7%) of 43 in the placebo group. The most common adverse event was diarrhoea (17 [31%] of patients in the 24 μg group, three [6%] in the 12 μg group, none in the placebo group). No life-threatening events or treatment-related deaths occurred.

INTERPRETATION

Lubiprostone was well tolerated and reduced the levels of liver enzymes in patients with NAFLD and constipation. Further studies are necessary to better define the efficacy and tolerability of lubiprostone in patients with NAFLD without constipation.

FUNDING

Mylan EPD G.K.

Metabolomic/lipidomic-based analysis of plasma to diagnose hepatocellular ballooning in patients with non-alcoholic fatty liver disease: A multicenter study

AIM

Liver biopsy is still required for the diagnosis of hepatocellular ballooning and inflammation, which are important histological features of non-alcoholic steatohepatitis. We undertook this multicenter, cross-sectional study to identify novel blood markers for the diagnosis of hepatocellular ballooning.

METHODS

We enrolled 176 patients, of whom 132 were proven by liver biopsy as having non-alcoholic fatty liver disease (NAFLD) and classified as non-ballooning (ballooning grade 0) (n = 83) or ballooning (ballooning grade 1 and 2) (n = 49) by a central pathology review. We carried out gas chromatography-mass spectrometry, hydrophilic interaction liquid chromatography tandem mass spectrometry, and lipidomics with plasma.

RESULTS

As correlates of hepatocellular ballooning, among the clinical parameters, serum type IV collagen 7S correlated most significantly with the ballooning grade (correlation coefficient [CC] = 0.463; P < 0.001). Among the metabolic/lipidomic markers, phosphatidylcholine (PC) (aa-44:8) correlated most significantly with the ballooning grade (CC = 0.394; P < 0.001). The area under the receiver operating characteristic curve of type IV collagen 7S, choline, and lysophosphatidylethanolamine (LPE) (e-18:2), was 0.846 (95% confidence interval, 0.772-0.919).

CONCLUSIONS

Plasma levels of PC were positively correlated, and those of lysophosphatidylcholine and LPE were negatively correlated with hepatocellular ballooning in NAFLD patients. These non-invasive metabolic/lipidomic-based plasma tests might be useful to distinguish between cases of NAFLD with and without hepatocellular ballooning.

Autotaxin is a valuable biomarker for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease

AIM

We investigated the characteristics of serum autotaxin (ATX) and its diagnostic performance for liver fibrosis in a large cohort of patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

We compared the usefulness of ATX and other fibrosis markers in 307 biopsy-confirmed NAFLD patients. In addition, in 145 participants with NAFLD, we compared the diagnostic performance of ATX with that of non-invasive imaging methods (vibration-controlled transient elastography and magnetic resonance elastography [MRE]).

RESULTS

Serum ATX concentration was significantly correlated with fibrosis stage in male and female NAFLD patients. In male patients, the area under the receiver operating characteristic (AUROC) curve values of ATX for the diagnosis of ≥stage 1, ≥stage 2, ≥stage 3, and ≥stage 4 fibrosis were 0.65, 0.75, 0.81, and 0.95, respectively. In female NAFLD participants, the AUROC values were all >0.81. The sensitivity of ATX was highest for the diagnosis of ≥stage 2 and ≥stage 3 fibrosis in both men and women with NAFLD. In the comparison between ATX and non-invasive imaging methods, the AUROC for MRE was the highest at every stage of fibrosis.

CONCLUSIONS

Serum ATX concentration is significantly correlated with fibrosis stage in NAFLD patients. The diagnostic accuracy of ATX for liver fibrosis is lower than that of MRE, but the sensitivities of ATX for the diagnosis of ≥stage 2 and ≥stage 3 were highest. We conclude that ATX is useful for the selection of patients requiring further evaluation for liver fibrosis.

Distribution of liver stiffness in non-alcoholic fatty liver disease with higher fibrosis-4 index than low cut-off index

BACKGROUND AND AIM

In the condition of high prevalence of non-alcoholic fatty liver disease (NAFLD), a new diagnostic algorithm to efficiently identify NAFLD patients with significant fibrosis is urgently required. We evaluated the predictive ability of the fibrosis-4 index (FIB-4 index) for significant liver fibrosis (F ≥ 2) in a cohort of Japanese patients with NAFLD.

METHODS

We prospectively calculated the FIB-4 index in patients who were incidentally diagnosed as fatty liver in medical checkups and then conducted liver stiffness measurement by vibration-controlled transient elastography (VCTE) only in patients in whom the FIB-4 index was more than the low cut-off index (> 1.45).

RESULTS

Of the 5929 people who underwent medical checkups, a total of 1374 people were identified as having fatty liver. Among these, we performed VCTE in 106 patients in whom the FIB-4 index was higher than 1.45. The distribution of the fibrosis stage as estimated by VCTE in the patients was as follows: F0, 52.8%; F1, 10.3%; F2, 21.6%; F3, 11.3%; and F4, 3.7%. The positive predictive value of the FIB-4 index for detecting NAFLD with significant fibrosis was 36.6%. The minimum value of the FIB-4 index was constant for each estimated fibrosis stage.

CONCLUSIONS

This is the first prospective study to evaluate the usefulness of the FIB-4 index as the first step to screen NAFLD patients with significant fibrosis. In Japan, addition of one further step that combined with the FIB-4 index is necessary to meaningfully reduce the number of patients needing liver stiffness measurement or liver biopsy.

Assessment of 10-year changes in liver stiffness using vibration-controlled transient elastography in non-alcoholic fatty liver disease

AIM

Although liver biopsy is the gold standard for the diagnosis and staging of non-alcoholic fatty liver disease (NAFLD), repeated assessment of patients' liver tissue conditions are impractical. We assessed the 10-year changes in liver stiffness measurements (LSM) utilizing vibration-controlled transient elastography in NAFLD patients.

METHODS

From January 2006 to September 2007, LSM was carried out for 97 biopsy-proven NAFLD patients. Of these, 34 patients underwent 10-year LSM reassessments (14 of them with paired biopsies).

RESULTS

We evaluated the changes in the fibrosis stage as estimated using LSM (FS-LSM). Over a 10-year period, 32.4% had FS-LSM progression, 50% had static disease, and 17.6% had FS-LSM improvement. From among the initially diagnosed non-alcoholic steatohepatitis patients, 18% had progressed to considerable stage 4 (cirrhosis) 10 years later. In this cohort, none of the patients who had been initially diagnosed as FS-LSM stage 0 had progressed to cirrhosis 10 years later. The changes in LSM were correlated with the change in the histological fibrosis stage, the NAFLD activity score, and the change in the sum of the steatosis, activity, and fibrosis score. Improving more than 1 body mass index (kg/m² ) and having a higher initial aspartate aminotransferase, alanine aminotransferase (ALT), or ALT responder (>30% improvement or reduction to less than 40 IU/L) were factors contributing to LSM improvements (≥2 kPa).

CONCLUSIONS

Vibration-controlled transient elastography is likely to become a more clinically important tool for the long-term monitoring of NAFLD patients.

New microwave ablation system for unresectable liver tumors that forms large, spherical ablation zones

BACKGROUND AND AIM

The aim of this study was to assess the efficacy of a new microwave ablation (MWA) system, the Emprint Ablation System, for the ablation of unresectable large liver tumors (≥ 30 mm).

METHODS

Twenty-one hepatic tumors (mean diameter, 34.7 mm) from 21 patients who underwent percutaneous MWA were included in this cross-sectional study. A volume analyzer based on computed tomography imaging was used for all patients within the month before and month after the procedure to evaluate the shape and volume of ablation zones. In addition, computed tomography imaging was performed again 3 months after the procedure to evaluate the presence of residual tumors and local recurrence.

RESULTS

Mean ablation time was 11.3 min, and mean overall procedure time was 33.4 min. An ablated adrenal gland-induced Takotsubo (stress) cardiomyopathy occurred immediately after MWA as a major complication in one patient. Roundness index A, B, and C presented a mean value of 0.94, 0.94, and 1.01, respectively (all values near 1 is a perfect sphere), indicating that a spherical ablation zone was achieved. The mean ablation volume was larger than the volume of tumors (24.5 vs 41.7 cm³ ). Residual tumors were confirmed in only 4.8% of tumors after a single ablation session. There was no local recurrence.

CONCLUSIONS

In our experience, the new MWA system provides an effective treatment option for unresectable large liver tumors. However, to ablate the liver tumors safely, it is necessary to consider the surrounding organs, such as the adrenal glands.

Magnetic resonance elastography increases usefulness and safety of non-invasive screening for esophageal varices

BACKGROUND AND AIMS

The Baveno VI criteria enable non-invasive screening for esophageal varices. However, these criteria were established based on studies examining a large proportion of patients with viral hepatitis and relatively few patients with non-alcoholic fatty liver disease (NAFLD). Furthermore, because vibration-controlled transient elastography (VCTE) has a high incidence of measurement error, improved criteria are needed. We aimed to develop criteria based on magnetic resonance elastography (MRE) even among patients with NAFLD.

METHODS

We performed a cross-sectional analysis of patients who had undergone MRE and/or VCTE as well as an esophagogastroduodenoscopy. The patients were classified as having either a low risk or a high risk of varices. The optimal cut-offs for ruling out esophageal varices were calculated for the MRE and VCTE liver stiffness measurement (LSM), the platelet count in an estimation cohort, and the cut-offs were then evaluated using validation cohorts composed of patients who had undergone only MRE or VCTE.

RESULTS

The study included 627 patients (39% with NAFLD). The optimal cut-off values for the MRE-LSM and the platelet count were 4.2 kPa and 18.0 × 10⁴ /μL, respectively. An MRE-LSM of 4.2 kPa plus a platelet count of 18.0 × 10⁴ /μL had a negative predictive value of 1.00 for both low-risk plus high-risk varices as well as for high-risk varices in a validation cohort, enabling the presence of varices to be ruled out.

CONCLUSIONS

Magnetic resonance elastography might enable a safer avoidance of screening endoscopy, with a smaller measurement error, among patient populations with a high prevalence of NAFLD.

Wisteria floribunda agglutinin-positive Mac-2-binding protein and type 4 collagen 7S: useful markers for the diagnosis of significant fibrosis in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

The fibrosis stage of liver is associated with the long-term outcomes in patients with non-alcoholic fatty liver disease (NAFLD). However, significant fibrosis, defined as fibrosis stages 2-4, is associated with an elevated risk of progression to severe liver disease; there have been scant reports about diagnosing significant fibrosis. We compare the noninvasive method and aim to identify appropriate liver fibrosis markers for detecting significant fibrosis in NAFLD patients.

METHODS

We compared the usefulness of liver fibrosis markers (Wisteria floribunda agglutinin-positive Mac-2-binding protein [WFA⁺ -M2BP], type 4 collagen 7S, etc.), clinical scoring systems, and liver stiffness measurement obtained using vibration-controlled transient elastography and magnetic resonance imaging-based magnetic resonance elastography in the same individuals and identified the most appropriate noninvasive method for detecting significant fibrosis in 165 patients with liver biopsy-diagnosed NAFLD.

RESULTS

The area under the receiver operating characteristic curve based on the serum cutoff index values of WFA⁺ -M2BP/the serum levels of type IV collagen 7S for the diagnosis of significant fibrosis was 0.832 (95% confidence interval: 0.771-0.894)/0.837 (95% confidence interval: 0.778-0.898). "WFA⁺ -M2BP (cutoff index) ≥ 0.83 or type IV collagen 7S ≥ 5.2 ng/mL" showed a high sensitivity (91.4%) and negative predictive value (87.9%) for the diagnosis of significant fibrosis.

CONCLUSIONS

We showed that serum WFA⁺ -M2BP or type IV collagen 7S levels serve as useful independent markers for detecting significant fibrosis and that use of both WFA⁺ -M2BP and type IV collagen 7S together increased the sensitivity and negative predictive value for the diagnosis of liver fibrosis. These results need to be validated in larger populations from multiple clinical centers.

Identification of differentially methylated region (DMR) networks associated with progression of nonalcoholic fatty liver disease

The progression of nonalcoholic fatty liver disease (NAFLD) is affected by epigenetics. We performed differentially methylated region (DMR) and co-methylation analyses to identify DMR networks associated with the progression of NAFLD. DMRs displaying differences in multiple consecutive differentially methylated CpGs between mild and advanced NAFLD were extracted. The average values of topological overlap measures for the CpG matrix combining two different DMRs were calculated and two DMR networks that strongly correlated with the stages of fibrosis were identified. The annotated genes of one network included genes involved in transcriptional regulation, cytoskeleton organization, and cellular proliferation. The annotated genes of the second network were primarily associated with metabolic pathways. The CpG methylation levels in these networks were strongly affected by age and fasting plasma glucose levels, which may be important co-regulatory factors. The methylation status of five DMRs in the second network was reversible following weight loss. Our results suggest that CpG methylation in DMR networks is regulated concomitantly via aging and hyperglycemia and plays important roles in hepatic metabolic dysfunction, fibrosis, and potential tumorigenesis, which occur during the progression of NAFLD. By controlling weight and blood glucose levels, the methylation of DMRs in the second network may be reduced.

Efficacy, safety, and tolerability of lubiprostone for the treatment of non-alcoholic fatty liver disease in adult patients with constipation: The LUBIPRONE, double-blind, randomised, placebo-controlled study design

BACKGROUND

This paper reports the protocol of a randomised, double-blind, placebo-controlled study to test the efficacy, safety, and tolerability of lubiprostone (LUB) vs. placebo on suppressing gut permeability in non-alcoholic fatty liver disease (NAFLD) patients with constipation. NAFLD, including non-alcoholic steatohepatitis (NASH), is a common chronic liver disorder. Progression is associated with increased gut permeability and gut-derived endotoxins. Most NAFLD/NASH clinical trial drugs aim to improve liver function or systemic metabolism. LUB is a type 2 chloride channel activator used as a laxative for the treatment of patients with constipation. LUB suppresses gut permeability induced by non-steroidal anti-inflammatory drugs in healthy volunteers and lowers blood endotoxin levels. There have been no clinical studies of LUB for NAFLD/NASH patients.

METHODS

The study plans to enrol adult patients (20-85 years, planned enrolment, n = 150; planned sample size, n = 120) with NAFLD and constipation, alanine aminotransferase ≥40 IU/L, equivalent steatosis grade ≥1, and equivalent fibrosis stage <4 measured using non-invasive vibration-controlled transient elastography and magnetic resonance imaging. Participants will be randomly allocated into three groups: LUB 12 μg, LUB 24 μg, and a placebo group.

RESULTS

The primary endpoint will be changes in alanine aminotransferase from baseline at 12 weeks. The main secondary endpoint will be changes in intestinal permeability from baseline at 12 weeks using the lactulose mannitol ratio.

CONCLUSIONS

This study will determine whether LUB improves gut permeability in NAFLD patients with constipation.

TRIAL REGISTRATION

This trial is registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000026635).

Identification of the genomic region under epigenetic regulation during non-alcoholic fatty liver disease progression

AIM

The progression of non-alcoholic fatty liver disease (NAFLD) is affected by epigenetics. We undertook co-methylation and differentially methylated region (DMR) analyses to identify the genomic region that is under epigenetic regulation during NAFLD progression.

METHODS

We collected liver biopsy specimens from 60 Japanese patients with NAFLD and classified these into mild (fibrosis stages 0-2) or advanced (fibrosis stages 3-4) NAFLD. We carried out a genome-wide DNA methylation analysis and identified the differentially methylated CpGs between mild and advanced NAFLD. Differentially methylated regions with multiple consecutive differentially methylated CpGs between mild and advanced NAFLD were extracted.

RESULTS

Co-methylation analysis showed that individual differentially methylated CpG sites were clustered into three modules. The CpG sites clustered in one module were hypomethylated in advanced NAFLD and their annotated genes were enriched for "immune system" function. The CpG sites in another module were hypermethylated and their annotated genes were enriched for "mitochondria" or "lipid particle", and "lipid metabolism" or "oxidoreductase activity". Hypomethylated DMRs included tumorigenesis-related genes (FGFR2, PTGFRN, and ZBTB38), the expressions of which are upregulated in advanced NAFLD. Tumor suppressor MGMT had two DMRs and was downregulated. Conversely, FBLIM1 and CYR61, encoding proteins that reduce cell proliferation, showed hypomethylated DMRs and were upregulated. Expression of the antioxidant gene NQO1 was upregulated, with a hypomethylated DMR. The DMR containing cancer-related MIR21 was hypomethylated in advanced NAFLD.

CONCLUSIONS

Co-methylation and DMR analyses suggest that the NAFLD liver undergoes mitochondrial dysfunction, decreased lipid metabolism, and impaired oxidoreductase activity, and acquires tumorigenic potential at the epigenetic level.

Identification of core gene networks and hub genes associated with progression of non-alcoholic fatty liver disease by RNA sequencing

AIM

Non-alcoholic fatty liver disease (NAFLD) progresses because of the interaction between numerous genes. Thus, we carried out a weighted gene coexpression network analysis to identify core gene networks and key genes associated with NAFLD progression.

METHODS

We enrolled 39 patients with mild NAFLD (fibrosis stages 0-2) and 21 with advanced NAFLD (fibrosis stages 3-4). Total RNA was extracted from frozen liver biopsies, and sequenced to capture a large dynamic range of expression levels.

RESULTS

A total of 1777 genes differentially expressed between mild and advanced NAFLD (q-value <0.05) clustered into four modules. One module was enriched for genes that encode cell surface or extracellular matrix proteins, and are involved in cell adhesion, proliferation, and signaling. This module formed a scale-free network containing four hub genes (PAPLN, LBH, DPYSL3, and JAG1) overexpressed in advanced NAFLD. PAPLN is a component of the extracellular matrix, LBH and DPYSL3 are reported to be tumor suppressors, and JAG1 is tumorigenic. Another module formed a random network, and was enriched for genes that accumulate in the mitochondria. These genes were downregulated in advanced NAFLD, reflecting impaired mitochondrial function. However, the other two modules did not form unambiguous networks. KEGG analysis indicated that 71 differentially expressed genes were involved in "pathways in cancer". Strikingly, expression of half of all differentially expressed genes was inversely correlated with methylation of CpG sites (q-value <0.05). Among clinical parameters, serum type IV collagen 7 s was most strongly associated with the epigenetic status in NAFLD.

CONCLUSIONS

Newly identified core gene networks suggest that the NAFLD liver undergoes mitochondrial dysfunction and fibrosis, and acquires tumorigenic potential epigenetically. Our data provide novel insights into the pathology and etiology of NAFLD progression, and identify potential targets for diagnosis and treatment.

Efficacy of glutathione for the treatment of nonalcoholic fatty liver disease: an open-label, single-arm, multicenter, pilot study

Background

Glutathione plays crucial roles in the detoxification and antioxidant systems of cells and has been used to treat acute poisoning and chronic liver diseases by intravenous injection. This is a first study examining the therapeutic effects of oral administration of glutathione in patients with nonalcoholic fatty liver disease (NAFLD).

Methods

The study was an open label, single arm, multicenter, pilot trial. Thirty-four NAFLD patients diagnosed using ultrasonography were prospectively evaluated. All patients first underwent intervention to improve their lifestyle habits (diet and exercise) for 3 months, followed by treatment with glutathione (300 mg/day) for 4 months. We evaluated their clinical parameters before and after glutathione treatment. We also quantified liver fat and fibrosis using vibration-controlled transient elastography. The primary outcome of the study was the change in alanine aminotransferase (ALT) levels.

Results

Twenty-nine patients finished the protocol. ALT levels significantly decreased following treatment with glutathione for 4 months. In addition, triglycerides, non-esterified fatty acids, and ferritin levels also decreased with glutathione treatment. Following dichotomization of ALT responders based on a median 12.9% decrease from baseline, we found that ALT responders were younger in age and did not have severe diabetes compared with ALT non-responders. The controlled attenuation parameter also decreased in ALT responders.

Conclusions

This pilot study demonstrates the potential therapeutic effects of oral administration of glutathione in practical dose for patients with NAFLD. Large-scale clinical trials are needed to verify its efficacy.

Trial registration

UMIN000011118 (date of registration: July 4, 2013).

Characteristics of non-obese non-alcoholic fatty liver disease: Effect of genetic and environmental factors

AIM

There are a considerable number of patients with non-obese non-alcoholic fatty liver disease (NAFLD). However, the clinical characteristics of non-obese NAFLD is not fully understood. We investigated genetic and other clinical parameters in non-obese and obese NAFLD.

METHODS

The single nucleotide polymorphism rs738409 in the patatin-like phospholipase 3 gene (PNPLA3) was genotyped by the Invader assay in 540 NAFLD patients (134 non-obese and 406 obese) and 1012 control subjects (782 non-obese and 230 obese). All NAFLD patients underwent liver biopsy. Odds ratios were calculated by multiple logistic regression analysis using age, sex, body mass index (BMI), type 2 diabetes mellitus (T2DM) and rs738409 genotype as explanatory variables.

RESULTS

Non-obese NAFLD subjects had a higher rs738409 GG genotype than obese NAFLD. Multiple logistic regression analysis indicated that the odds ratios of T2DM and rs738409 GG genotype for NAFLD were higher in non-obese than in obese groups. In non-obese NAFLD, rs738409 GG genotype was associated with lobular inflammation, hepatocyte ballooning and NAFLD activity score. In obese NAFLD, BMI and T2DM but not rs738409 GG genotype were associated with severity of histology.

CONCLUSION

We demonstrated that the risk factors for the development and progression of NAFLD were different between non-obese and obese patients and that PNPLA3 rs738409 was strongly associated with the development and progression of non-obese NAFLD.

Magnetic Resonance Imaging More Accurately Classifies Steatosis and Fibrosis in Patients With Nonalcoholic Fatty Liver Disease Than Transient Elastography

BACKGROUND & AIMS

Noninvasive methods have been evaluated for the assessment of liver fibrosis and steatosis in patients with nonalcoholic fatty liver disease (NAFLD). We compared the ability of transient elastography (TE) with the M-probe, and magnetic resonance elastography (MRE) to assess liver fibrosis. Findings from magnetic resonance imaging (MRI)-based proton density fat fraction (PDFF) measurements were compared with those from TE-based controlled attenuation parameter (CAP) measurements to assess steatosis.

METHODS

We performed a cross-sectional study of 142 patients with NAFLD (identified by liver biopsy; mean body mass index, 28.1 kg/m(2)) in Japan from July 2013 through April 2015. Our study also included 10 comparable subjects without NAFLD (controls). All study subjects were evaluated by TE (including CAP measurements), MRI using the MRE and PDFF techniques.

RESULTS

TE identified patients with fibrosis stage ≥2 with an area under the receiver operating characteristic (AUROC) curve value of 0.82 (95% confidence interval [CI]: 0.74-0.89), whereas MRE identified these patients with an AUROC curve value of 0.91 (95% CI: 0.86-0.96; P = .001). TE-based CAP measurements identified patients with hepatic steatosis grade ≥2 with an AUROC curve value of 0.73 (95% CI: 0.64-0.81) and PDFF methods identified them with an AUROC curve value of 0.90 (95% CI: 0.82-0.97; P < .001). Measurement of serum keratin 18 fragments or alanine aminotransferase did not add value to TE or MRI for identifying nonalcoholic steatohepatitis.

CONCLUSIONS

MRE and PDFF methods have higher diagnostic performance in noninvasive detection of liver fibrosis and steatosis in patients with NAFLD than TE and CAP methods. MRI-based noninvasive assessment of liver fibrosis and steatosis is a potential alternative to liver biopsy in clinical practice. UMIN Clinical Trials Registry No. UMIN000012757.

The Selective SGLT2 Inhibitor Ipragliflozin Has a Therapeutic Effect on Nonalcoholic Steatohepatitis in Mice

Background & Aims

In recent years, nonalcoholic steatohepatitis (NASH) has become a considerable healthcare burden worldwide. Pathogenesis of NASH is associated with type 2 diabetes mellitus (T2DM) and insulin resistance. However, a specific drug to treat NASH is lacking. We investigated the effect of the selective sodium glucose cotransporter 2 inhibitor (SGLT2I) ipragliflozin on NASH in mice.

Methods

We used the Amylin liver NASH model (AMLN), which is a diet-induced model of NASH that results in obesity and T2DM. AMLN mice were fed an AMLN diet for 20 weeks. SGLT2I mice were fed an AMLN diet for 12 weeks and an AMLN diet with 40 mg ipragliflozin/kg for 8 weeks.

Results

AMLN mice showed steatosis, inflammation, and fibrosis in the liver as well as obesity and insulin resistance, features that are recognized in human NASH. Ipragliflozin improved insulin resistance and liver injury. Ipragliflozin decreased serum levels of free fatty acids, hepatic lipid content, the number of apoptotic cells, and areas of fibrosis; it also increased lipid outflow from the liver.

Conclusions

Ipragliflozin improved the pathogenesis of NASH by reducing insulin resistance and lipotoxicity in NASH-model mice. Our results suggest that ipragliflozin has a therapeutic effect on NASH with T2DM.

Non-alcoholic fatty liver disease comorbid with major depressive disorder: The pathological features and poor therapeutic efficacy

BACKGROUND AND AIM

Major depressive disorder (MDD) is an important public health problem, and it is often comorbid with many chronic diseases. The purpose of this study was to identify the clinical features of non-alcoholic fatty liver disease (NAFLD) patients comorbid with MDD and to investigate the influence of MDD on the effect of treatment in patients with NAFLD.

METHODS

A total of 258 patients with biopsy-proven NAFLD were included. MDD was diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision. The patients were followed up for 48 weeks under standard care for NAFLD, which consisted mainly of lifestyle modification.

RESULTS

There were 32 patients comorbid with MDD. They were characterized by more severe histological steatosis and higher NAFLD activity score, and also significantly higher levels of serum aminotransferase, γ-glutamyl transpeptidase and ferritin, than age-and-sex-matched NAFLD patients without MDD. Moreover, NAFLD patients with MDD showed poor response to the standard care for NAFLD, in body weight loss and in other parameters. Particularly, NAFLD patients with unstable MDD (not in full/partial remission) showed severe resistance to the treatment.

CONCLUSION

This is the first study to demonstrate the clinical features and response to therapy of NAFLD patients comorbid with MDD. The comorbid state of MDD was associated with more severe histological liver steatosis and worse treatment outcomes in patients with NAFLD. Further investigations are required to develop new lifestyle modification programs that enable NAFLD patients with MDD to achieve the treatment goal.

LDL-migration index (LDL-MI), an indicator of small dense low-density lipoprotein (sdLDL), is higher in non-alcoholic steatohepatitis than in non-alcoholic fatty liver: a multicenter cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is associated with increased risks of atherosclerotic diseases, including cardiovascular disease. However, the difference in risk between patients with non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) has not yet been determined. Accumulating evidence has shown that high amounts of small dense low-density lipoprotein (sdLDL) are closely associated with atherosclerotic diseases. This study investigated differences in risk factors for atherosclerotic diseases, especially LDL-migration index (LDL-MI), an indicator of sdLDL, between patients with NAFL and NASH.

Methods

LDL-MI was analyzed in a primary cohort of 156 patients with NAFLD, including 53 with NAFL and 103 with NASH, and a validation cohort of 69 patients with NAFLD, including 25 with NAFL and 44 with NASH.

Results

In the primary cohort, NASH was associated with elevated LDL-MI (p = 0.039). Multiple regression analysis showed that NASH and the non-use of lipid lowering medications were independently correlated with higher LDL-MI in all patients with NAFLD. Among patients not on lipid lowering medications, those with NASH had significantly higher LDL-MI than those with NAFL (p = 0.001). These findings were confirmed in a validation cohort, in that LDL-MI was significantly higher in patients with NASH than with NAFL (p = 0.043).

Conclusion

This study is the first to show that LDL-MI, an indicator of sdLDL, was higher in patients with NASH than with NAFL, suggesting that the risk of atherosclerotic diseases may be higher in NASH than NAFL. Patients with NASH should be followed closely, especially for the progression of liver pathology and atherosclerotic diseases.

Trial Registration

UMIN000009614

Hepatic triglyceride lipase plays an essential role in changing the lipid metabolism in genotype 1b hepatitis C virus replicon cells and hepatitis C patients

AIM

Recently, several studies have shown the existence of associations between lipoprotein profiles and hepatitis C virus (HCV), although only a limited amount of information is available about the mechanisms underlying the changes in the lipoprotein profiles associated with HCV. In this study, we investigated the association between lipoprotein profile, classified according to the particle size, and lipoprotein metabolism.

METHODS

We used four kinds of cells for this experiment; full-length genome HCV RNA replicon cells (OR6), sub-genomic HCV RNA replicon cells (sO), and OR6c cells and sOc cells, which were the same cell lines treated with interferon-α. The triglyceride (TG) levels in the lipoprotein subclasses of the culture medium were measured by high-performance liquid chromatography. The mRNA expression levels of several molecules associated with lipoprotein metabolism were measured in the OR6, OR6c, sO and sOc cells. To confirm some of the results obtained using the in vitro system, liver biopsy samples obtained from the patients were also examined.

RESULTS

The content of TG in the large low-density lipoprotein (LDL) and medium LDL in the culture medium was increased only in the OR6 cells. The hepatic triglyceride lipase (HTGL) mRNA expression levels were lower in the OR6 cells than in the OR6c cells (P < 0.01). Examination of the HTGL expression levels in the patients' livers revealed a decrease in HTGL expression in the chronic hepatitis C liver as compared with that in the chronic hepatitis B or non-alcoholic steatohepatitis liver (P < 0.01).

CONCLUSION

We showed that HCV inhibits HTGL production in hepatocytes, inducing a change of the lipoprotein profile.

Emerging drugs for non-alcoholic steatohepatitis

INTRODUCTION

The prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) is increasing along with the worldwide epidemic of obesity and their strong association with metabolic syndrome. Currently existing pharmacological therapies include anti-oxidants, insulin-sensitizing agents, lipid-lowering drugs and cytoprotective agents, but there is a lack of consensus regarding the most effective and appropriate pharmacologic therapies for NASH. Clinical trials examining new therapeutic drugs for NASH that act via various mechanisms are being performed in several countries, and these drugs may strongly influence current NASH treatment.

AREAS COVERED

This article provides a review of recent data on the safety and efficacy of existing and emerging agents for the treatment of NASH.

EXPERT OPINION

Ideally, treatment for NASH should not only improve liver disease, but also reduce the risks of adverse cardiovascular outcomes and the development of diabetes and cancers. However, this goal is likely to be too high in the context of clinical trials designed to obtain approval for the treatment of liver disease. The only way to achieve the goal is to accumulate the results of these relatively short-term clinical trials.

Evaluation of the Liver Fibrosis Index calculated by using real-time tissue elastography for the non-invasive assessment of liver fibrosis in chronic liver diseases

AIM

A rapid and non-invasive method of detecting fibrosis in patients with chronic liver diseases is of major clinical interest. The purpose of this study was to comparatively investigate the effectiveness of the Liver Fibrosis Index (LF Index) calculated using real-time tissue elastography (RTE) in patients with non-alcoholic fatty liver disease (NAFLD) and patients with chronic hepatitis C (CHC).

METHODS

Twenty-seven patients with biopsy-proven NAFLD and 93 patients with biopsy-proven CHC were included. They underwent transient elastography (TE), serum liver fibrosis marker testing and RTE to calculate the LF Index.

RESULTS

The LF Index showed a stepwise increase with increasing histological severity of fibrosis in CHC patients (P = 0.0102), whereas no significant correlation of the LF Index with the histological severity of liver fibrosis in NAFLD patients (P = 0.852). There was a significant correlation between the LF Index and liver stiffness measured by TE in CHC patients (r = 0.319, P = 0.0009). On the other hand, no such correlation was observed in NAFLD patients. While in CHC patients, the LF Index was correlated with the FIB-4 index, no such correlation was observed in NAFLD patients.

CONCLUSION

The LF Index calculated by RTE is effective for assessment of liver fibrosis in patients with CHC. On the other hand, it is not useful in patients with NAFLD. This is the first study to compare the clinical usefulness of RTE as non-invasive assessment of liver fibrosis between CHC and NAFLD. Further investigations are required to refine statistical assessment of RTE.

[A case of HER2-positive gastric cancer successfully treated with trastuzumab plus capecitabine plus cisplatin chemotherapy as third-line treatment]

A 67-year-old woman was diagnosed as having advanced gastric cancer(poorly differentiated adenocarcinoma)with multiple liver metastases. She had received combined S-1 plus cisplatin chemotherapy as first-line treatment and weekly paclitaxel chemotherapy as second-line treatment, however, both had eventually proved ineffective. Because the gastric cancer was HER2-positive, she was treated with trastuzumab plus capecitabine plus cisplatin(XP)chemotherapy as third-line treatment. The primary lesion and liver metastatic lesions were confirmed to show remarkable regression. The ToGA trial revealed increased efficacy of trastuzumab in first-line treatment of cancers showing high expression levels of the HER2- protein. This case suggested the increased efficacy of trastuzumab in third-line treatment. Neutropenia and hand foot syndrome of grade 2 were all reported adverse events. She could receive trastuzumab plus XP chemotherapy safely by dose reduction or dormancy temporarily of capecitabine.

Soluble CD14 levels reflect liver inflammation in patients with nonalcoholic steatohepatitis

BACKGROUND AIMS

Liver inflammation is a risk factor for the progression of nonalcoholic fatty liver disease (NAFLD). However, the diagnosis of liver inflammation is very difficult and invasive liver biopsy is still the only method to reliably detect liver inflammation. We previously reported that overexpression of CD14 in Kupffer cells may trigger the progression to nonalcoholic steatohepatitis (NASH) via liver inflammation following hyper-reactivity to low-dose lipopolysaccharide. Therefore, the aim of this study was to investigate the relationship between soluble type of CD14 (sCD14) and histological features in patients with NAFLD.

METHODS

Our cohort consisted of 113 patients with liver biopsy-confirmed NAFLD and 21 age-matched healthy controls. Serum sCD14 levels were measured by an enzyme-linked immunosorbent assay.

RESULTS

Serum sCD14 levels were significantly associated with diagnosis of NASH and the area under the receiver operator characteristic curve (AUROC) to distinguish between not NASH and NASH was 0.802. Moreover, serum sCD14 levels were significantly associated with the disease activity based on NAFLD activity score and hepatic CD14 mRNA expression, which is correlated with membrane CD14 (mCD14) expression, in patients with NAFLD. In multiple regression analysis, the serum sCD14 levels were independently associated with liver inflammation. The AUROC to distinguish between mild and severe liver inflammation in patients with NAFLD was 0.752.

CONCLUSIONS

We found that serum sCD14 levels increased significantly with increasing liver inflammation grade in patients with NAFLD, reflecting increased hepatic CD14 expression. Serum sCD14 is a promising tool to predict the worsening of liver inflammation, and may offer a potential biomarker for evaluation of therapeutic effects in NAFLD.

Unfolded protein response pathways regulate Hepatitis C virus replication via modulation of autophagy

Background

Hepatitis C virus (HCV) induces endoplasmic reticulum (ER) stress which, in turn, activates the unfolding protein response (UPR). UPR activates three distinct signalling pathways. Additionally, UPR induces autophagy (UPR-autophagy pathways). On the other hand, it has become clear that some positive-single-strand RNA viruses utilize autophagy. Some groups have used the siRNA silencing approach to show that autophagy is required for HCV RNA replication. However, the mechanism of induction of the UPR-autophagy pathways remain unclear in the cells with HCV.

Method and results: we used a genome-length HCV RNA (strain O of genotype 1b) replication system (OR6) in hepatoma cells (HuH-7-derived OR6 cells). As control, we used OR6c cells from which the HCV genome had been removed by treatment with interferon-α. The UPR-autophagy pathways were activated to a greater degree in the OR6 cells as compared to the OR6c cells. Rapamycin, mTOR-independent autophagy inducer, activated HCV replication in the OR6 cells. On the other hand, HCV replication in the cells was inhibited by 3-methyladenine (3-MA), which is an inhibitor of autophagy. Salubrinal (Eukaryotic Initiation Factor 2(eIF2)-alpha phosphatase inhibitor), 3-ethoxy-5, 6-dibromosalicylaldehyde (X-box binding protein-1 (XBP-1) splicing inhibitor) and sp600125 (c-Jun N-terminal kinases (JNK) inhibitor) inhibited HCV replication and autophagy. Additionally, HCV replication and autophagy were inhibited more strongly by combination of these inhibitors.

Conclusion

Our results suggest that UPR-autophagy pathways exert an influence on HCV replication. Therefore, control these pathways may serve as a novel therapeutic strategy against replication of HCV.

Risk factors for colonic diverticular hemorrhage: Japanese multicenter study

BACKGROUND AND AIM

Diverticular hemorrhage is the common cause of lower gastrointestinal bleeding, and its incidence has been increasing in Japan. However, the exact cause of diverticular hemorrhage is not well understood. We investigated the risk factors for diverticular hemorrhage.

METHODS

We selected 103 patients with diverticular hemorrhage as cases and patients with colonic diverticulosis without a history of bleeding were selected as control subjects, exactly matched for age and gender. We collected the data from the medical records of each of the patients, such as those related to the comorbidities, medications and findings of colonoscopy, and conducted a matched case-control study to analyze the risk factors for diverticular hemorrhage.

RESULTS

Both groups were composed of 75 men and 28 women. The median age of the patients in both groups was 72.0 years (47.0-87.0). The body weight (p = 0.0065), body mass index (p = 0.006), prevalence of hypertension (p = 0.0242), prevalence of ischemic heart disease (p = 0.0015), and frequency of use of low-dose aspirin (p = 0.042) were significantly different between the two groups. The percentage of patients with bilateral diverticula, that is, diverticula on both the right and left hemicolon, was significantly higher in the diverticular hemorrhage group (p = 0.0011). Multiple regression analysis identified only the diverticular location as being significantly associated with the risk of diverticular hemorrhage (p = 0.0021).

CONCLUSIONS

Only the diverticular location (bilateral) was found to be an independent risk factor for diverticular hemorrhage.

Non-alcoholic fatty liver disease adversely affects the glycemic control afforded by sitagliptin

BACKGROUND/AIMS

Recently, high serum DPP-4 activity was found in patients with NAFLD. Therefore, the possibility of NAFLD adversely influencing the therapeutic effect afforded by DPP-4 inhibitors in type 2 diabetic patients was suggested.

METHODOLOGY

A total of 20 type 2 DM patients with NAFLD and 85 type 2 DM patients without NAFLD were enrolled in the present study. The patients were administered sitagliptin at the dose of 50 mg/day for 12 weeks.

RESULTS

The change in HbA1c from the baseline following treatment with sitagliptin was -0.47% (4 weeks), -0.73% (8 weeks) and -0.88% (12 weeks) in the type 2 DM patients with NAFLD and -0.26% (4 weeks), -0.41% (8 weeks) and -0.49% (12 weeks) in type 2 DM without NAFLD. The changes in the HbA1c from the baseline after sitagliptin treatment for 8 and 12 weeks were significantly greater in type 2 DM patients with NAFLD than in type 2 DM patients without NAFLD.

CONCLUSIONS

The results of this study suggest that NAFLD might adversely affect the therapeutic effect afforded by sitagliptin treatment in patients with type 2 DM. NAFLD may be an independent predictor of the effect of sitagliptin in patients with type 2 DM.

Capsule endoscopy with flexible spectral imaging color enhancement reduces the bile pigment effect and improves the detectability of small bowel lesions

BACKGROUND

Capsule endoscopy with flexible spectral imaging color enhancement (CE-FICE) has been reported to improve the visualization and detection of small-bowel lesions, however, its clinical usefulness is still not established. Therefore, we conducted a study to evaluate whether CE-FICE contributes to improve the detectability of small-bowel lesions by CE trainees.

METHODS

Four gastroenterology trainees without prior CE experience were asked to read and interpret 12 CE videos. Each of the videos was read by conventional visualization method and under three different FICE settings. To evaluate whether the lesion recognition ability of the CE trainees could be improved by the FICE technology, the lesion detection rate under each of the three FICE settings was compared with that by conventional CE. CE trainees tend to miss small-bowel lesions in bile-pigment-positive condition, therefore we evaluated whether CE-FICE contributes to reducing the bile-pigment effect. The bile-pigment condition was determined by the color values around the small-bowel lesions according to the results of the receiver-operating-characteristic analysis. Moreover, we also evaluated whether poor bowel preparion might affect the accuracy of lesion recognition by CE-FICE.

RESULTS

Of a total of 60 angioectasias, CE trainees identified 26 by conventional CE, 40 under FICE setting 1, 38 under FICE setting 2, and 31 under FICE setting 3. Of a total of 82 erosions/ulcerations, CE trainees identified 38 by conventional CE, 62 under FICE setting 1, 60 under FICE setting 2, and 20 under FICE setting 3. Compared with conventional CE, FICE settings 1 and 2 significantly improved the detectability of angioectasia (P = 0.0017 and P = 0.014, respectively) and erosions/ulcerations (P = 0.0012 and P = 0.0094, respectively). Although the detectability of small-bowel lesions by conventional CE (P = 0.020) and under FICE setting 2 (P = 0.0023) was reduced by the presence of bile-pigments, that under FICE setting 1 was not affected (P = 0.59). Our results also revealed that in poor bowel visibility conditions, CE-FICE yielded a high rate of false-positive findings.

CONCLUSIONS

CE-FICE may reduce the bile-pigment effect and improve the detectability of small-bowel lesions by CE trainees; the reliability of CE-FICE may be improved by good bowel preparation.

Influence of inducible nitric oxide synthase polymorphisms in Japanese patients with non-alcoholic fatty liver disease

AIM

Genetic factors as well as environmental factors play an important role in the development of non-alcoholic fatty liver disease (NAFLD). Recently, inducible nitric oxide synthase (iNOS) was significantly higher in the severest form of non-alcoholic steatohepatitis (NASH), and nitric oxide (NO) has been determined to play an important role in the process of fibrosis in NASH. In this study, we investigated iNOS gene polymorphisms for associations with NAFLD.

METHODS

A total of 115 NAFLD patients, consisting of 65 patients with NASH and 50 patients with simple steatosis, in whom a positive diagnosis had been made by liver biopsy, and 435 healthy control subjects, were recruited into this study.

RESULTS

We investigated 10 single nucleotide polymorphisms (SNP) of the iNOS gene, one of which, rs1060822, had the lowest P-value in the allele frequency model (P = 0.00078) with an odds ratio (95% confidence interval) of 0.49 (0.32-0.75). Four SNP, rs2297510, rs2297511, rs2797512 and rs1060822, were significantly associated with NAFLD, even when the most conservative Bonferroni's correction was applied. Linkage disequilibrium analysis revealed that SNP rs1060822 and three other SNP, rs2297510, rs2297511 and rs2797512, were in the same block. We also investigated associations between rs1060822 genotypes and the fibrosis index, and the results of the analysis revealed an additive increase in the fibrosis index and intrahepatic iNOS mRNA expression in the patients with the T allele of rs1060822.

CONCLUSION

This is the first study to identify genetic variations in iNOS that may influence the risk of NAFLD and liver fibrosis in NAFLD.