Nonalcoholic fatty liver disease: from clinical recognition to treatment

Genetic polymorphism in CD14 gene, a co-receptor of TLR4 associated with non-alcoholic fatty liver disease

AIM

To evaluate the pathogenic role of toll-like receptor (TLR) gene polymorphisms in patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

Two hundred and fifty subjects (NAFLD = 200, healthy volunteers = 50) underwent polymerase chain reaction and restriction fragment length polymorphism to assess one polymorphism in the toll-like receptor 2 (TLR2) gene (A753G), two polymorphisms in the TLR4 gene (TLR4 Asp299Gly and Thr399Ile allele), and two polymorphisms in the cluster of differentiation 14 (CD14) (C-159T and C-550T) gene, a co-receptor of TLR4. Association of TLR gene polymorphisms with NAFLD and its severity was evaluated by genetic models of association.

RESULTS

On both multiplicative and recessive models of gene polymorphism association, there was significant association of CD14 C (-159) T polymorphism with NAFLD; patients with TT genotype had a 2.6 fold increased risk of developing NAFLD in comparison to CC genotype. There was no association of TLR2 Arg753Gln, TLR4 Asp299Gly, Thr399Ile, and CD14 C (-550) T polymorphisms with NAFLD. None of the TLR gene polymorphisms had an association with histological severity of NAFLD.

CONCLUSION

Patients with CD14 C (-159) T gene polymorphism, a co-receptor of TLR4, have an increased risk of NAFLD development.

The increasing burden of potentially preventable liver disease among adult liver transplant recipients: A comparative analysis of liver transplant indication by era in Australia and New Zealand

BACKGROUND

Hepatitis C (HCV), hepatitis B (HBV), alcohol-related liver disease (ALD), and non-alcohol-related fatty liver disease (NAFLD) are leading indications for adult liver transplantation in Australia and New Zealand. However, these diseases are potentially preventable through effective primary and/or secondary prevention strategies. This study evaluates the relative contribution of potentially preventable liver diseases to liver transplant numbers in Australia and New Zealand over time.

METHODS

Prospectively recorded clinical, demographic, and outcome data were collected from the Australian and New Zealand Liver Transplant Registry for all primary adult liver transplants performed in Australia and New Zealand from 1 January 1985 until 31 December 2012. Potentially preventable liver disease was defined as HBV, HCV, NAFLD, ALD, and HCC. The etiology of liver disease leading to liver transplantation and the proportion of preventable liver disease-related liver transplantation was compared between Era 1 (1985-1993), Era 2 (1994-2003), and Era 3 (2004-2012).

RESULTS

Overall, 1252 of 3266 adult primary liver transplants (38.3%) were performed for potentially preventable liver disease. There was a significant increase in the proportion of liver transplants because of preventable liver disease from 21.2% (93 of 439) in Era 1, to 49.8% (623 of 1252) in Era 2 and 63.5% (1000 of 1575) in Era 3 (P < 0.0001). Over time, there was a significant increase in HCV (P < 0.0001), ALD (P = 0.002), and NAFLD (P < 0.0001) as a primary indication for adult liver transplant, whereas HBV has significantly decreased from Era 1 to Era 3 as an indication for transplant (P < 0.0001). The number of transplants performed for HCC also increased across Eras (P < 0.0001), with 84% due to underlying potentially preventable liver disease.

CONCLUSION

Since 2004, the majority of primary adult liver transplants within Australia and New Zealand have been because of potentially preventable liver diseases and the prevalence of these diseases has increased over time. This finding represents an opportunity for clinicians to make a significant impact on the overall burden of advanced liver disease in Australia and New Zealand by improving primary and secondary prevention measures.

The predictive value of steatosis in hepatitis C virus infection

Steatosis is a complication of hepatitis C virus (HCV) infection and the mechanisms of its development are complex, involving viral and host factors. Steatosis that is prevalently viral is associated with HCV genotype 3, and steatosis that is prevalently metabolic is associated with non-3 genotypes. Viral steatosis is correlated with the level of HCV replication, whereas metabolic steatosis is related to insulin resistance. The two types of steatosis have a different impact on HCV disease and may have an additive effect. HCV infection is a multifaceted disease with hepatic and extrahepatic manifestations. There is a body of evidence indicating that HCV-related steatosis plays a role in many HCV manifestations and, thus, the presence of steatosis is a predictive factor for the development of such events. The current data show that HCV-related steatosis predicts an advanced liver disease and a more rapid progression of fibrosis, as well as an increased risk of development of hepatocellular carcinoma. Moreover, the presence of steatosis in a HCV patient has a high predictive value that the subject may have or may develop insulin resistance, diabetes and metabolic syndrome. Recently, a strict association between HCV-related steatosis and development of atherosclerosis has been demonstrated. In addition, steatosis negatively impacts response rate to interferon-based treatment, even in HCV genotype-3 infection. Therapeutic strategies to improve steatosis and, consequently, response to standard antiviral therapy and outcome of disease are wanted. The authors summarize current knowledge of impact of steatosis on the above reported clinical conditions associated with HCV infection.

Effective therapy using voglibose for nonalcoholic steatohepatitis in a patient with insufficient dietary and exercise therapy: exploring other treatment possibilities

A 56-year-old Japanese female with a 10-year history of thyroiditis presented to our institution. The laboratory data and clinical findings suggested that the patient had complicated nonalcoholic fatty liver disease or nonalcoholic steatohepatitis (NASH) with autoimmune hepatitis according to the criteria by the application of the International Autoimmune Hepatitis score. The patient could not manage by herself so dietary- and exercise-based treatment was difficult. Accordingly, ursodeoxycholic acid and ezetimibe therapy was started and continued until the performance of a liver needle biopsy to define the diagnosis. However, no improvement in liver function was observed. In addition, pathological findings indicated that the patient had NASH. The patient was finally diagnosed as having NASH. Therefore, voglibose was added to the ursodeoxycholic acid and ezetimibe therapy, and this addition of voglibose actually took effect. The patient's serum aspartate transaminase and alanine aminotransferase levels decreased dramatically. This report is the first to document other treatment possibilities of NASH in a case when dietary therapy is difficult.

Combination of conjugated linoleic acid with fish oil prevents age-associated bone marrow adiposity in C57Bl/6J mice

The inverse relationship between fat in bone marrow and bone mass in the skeleton of aging subjects is well known. However, there is no precise therapy for the treatment of bone marrow adiposity. We investigated the ability of conjugated linoleic acid (CLA) and fish oil (FO), alone or in combination, to modulate bone loss using 12 months old C57Bl/6J mice fed 10% corn oil diet as control or supplemented with 0.5% CLA or 5% FO or 0.5% CLA+5% FO for 6 months. We found, CLA-fed mice exhibited reduced body weight, body fat mass (BFM) and enhanced hind leg lean mass (HLLM) and bone mineral density (BMD) in different regions measured by dual energy x-ray absorptiometry (DXA); however, associated with fatty liver and increased insulin resistance; whereas, FO fed mice exhibited enhanced BMD, improved insulin sensitivity, with no changes in BFM and HLLM. Interestingly, CLA+FO fed mice exhibited reduced body weight, BFM, peroxisome proliferator-activated receptor gamma and cathepsin K expression in bone marrow with enhanced BMD and HLLM. Moreover, CLA+FO supplementation reduced liver hypertrophy and improved insulin sensitivity with remarkable attenuation of bone marrow adiposity, inflammation and oxidative stress in aging mice. Therefore, CLA with FO combination might be a novel dietary supplement to reduce fat mass and improve BMD.