NAFLD (Non-Alcoholic Fatty Liver Disease) is an increasingly significant public health issue, regarded as the most relevant liver disease of the twenty-first century. Approximately 20%-30% of NAFLD ...subjects develop a NASH (Non-Alcoholic Steato-Hepatitis), a condition which can potentially evolve to liver cirrhosis and hepatocellular carcinoma. For these reasons a proper evaluation of liver damage is a key point for diagnosis and prognosis and liver biopsy still remains the "gold standard" procedure both for discrimination between steatosis and steatohepatitis and assessment of the degree of liver fibrosis. Nonetheless, given it is an invasive, painful and costly procedure, a great research efforts have been made in order to develop non-invasive methods for the assessment of NAFLD presence and/or severity by serum markers and imaging techniques. In this review we aimed to perform a comprehensive review of the literature about strengths and weaknesses of the main tools available for the non-invasive assessment of NAFLD patients.
Aliment Pharmacol Ther 2012; 35: 238–247
Summary
Background Metabolic factors have been associated with liver damage in patients with non‐alcoholic fatty liver disease (NAFLD).
Aims To test a new ...marker of adipose dysfunction, the visceral adiposity index (VAI), in NAFLD patients to assess whether or not it is associated with host factors, and to investigate a potential correlation with histological findings.
Methods One hundred and forty‐two consecutive NAFLD patients were evaluated by liver biopsy, and clinical and metabolic measurements, including insulin resistance with the homeostasis model assessment (HOMA), and VAI by using waist circumference, body mass index, triglycerides and HDL. Serum levels of TNFα, IL‐6, adiponectin and leptin were also assessed. All biopsies were scored for NAFLD activity score (NAS) and its components, and for staging (Kleiner).
Results By multiple linear regression analysis, VAI was independently associated with higher HOMA (P = 0.04), and fibrosis (P = 0.04). In addition, an independent association was found between higher VAI and lower adiponectin levels (P = 0.002). Higher HOMA (OR 1.149, 95% CI 1.003–1.316, P = 0.04), higher VAI (OR 1.446, 95% CI 1.023–2.043, P = 0.03), lobular inflammation (OR 3.777, 95% CI 1.771–8.051, P = 0.001), and ballooning (OR 2.884, 95% CI 1.231–6.757, P = 0.01) were correlated with significant fibrosis (F2–F4) on multiple logistic regression analysis. In particular, the prevalence of significant fibrosis progressively increased from patients with a VAI ≤ 2.1 and HOMA ≤ 3.4 (26%) to those with a VAI > 2.1 and HOMA > 3.4 (83%).
Conclusions In NAFLD patients, visceral adiposity index is an expression of both qualitative and quantitative adipose tissue dysfunction and, together with insulin resistance, is independently correlated with significant fibrosis.
Summary
Background
Host genetic modifiers of the natural history of chronic hepatitis B (CHB) remain poorly understood. Recently, a genome‐wide association study (GWAS)‐identified polymorphism in the ...STAT4 gene that contributes to the risk for hepatocellular carcinoma (HCC) was shown to be associated with the full spectrum of hepatitis B virus (HBV) outcomes in Asian patients. However, the functional mechanisms for this effect are unknown and the role of the variant in modulating HBV disease in Caucasians has not been investigated.
Aims
To determine whether STAT4 genetic variation is associated with liver injury in Caucasian patients with CHB and to investigate potential mechanisms mediating this effect.
Methods
STAT4 rs7574865 was genotyped in 1085 subjects (830 with CHB and 255 healthy controls). STAT4 expression in liver, PBMCs and NK cells, STAT4 phosphorylation and secretion of interferon‐gamma (IFN‐γ) according to STAT4 genetic variation was examined.
Results
STAT4 rs7574865 genotype was independently associated with hepatic inflammation (OR: 1.42, 95% CI: 1.07‐2.06, P = 0.02) and advanced fibrosis (OR: 1.83, 95% CI: 1.19‐2.83, P = 0.006). The minor allele frequency of rs7574865 was significantly lower than that in healthy controls. rs7574865 GG risk carriers expressed lower levels of STAT4 in liver, PBMCs and in NK cells, while NK cells from patients with the risk genotype had impaired STAT4 phosphorylation following stimulation with IL‐12/IL‐18 and a reduction in secretion of IFN‐γ.
Conclusion
Genetic susceptibility to HBV persistence, hepatic inflammation and fibrosis in Caucasians associates with STAT4 rs7574865 variant. Downstream effects on NK cell function through STAT4 phosphorylation‐dependent IFN‐γ production likely contribute to these effects.
Objectives
Current guidelines recommend use of a diagnostic algorithm to assess disease severity in cases of suspected nonalcoholic fatty liver disease (NAFLD). We applied this algorithm to ...HIV‐monoinfected patients.
Methods
We analysed three prospective screening programmes for NAFLD carried out in the following cohorts: the Liver Disease in HIV (LIVEHIV) cohort in Montreal, the Modena HIV Metabolic Clinic (MHMC) cohort and the Liver Pathologies in HIV in Palermo (LHivPa) cohort. In the LIVEHIV and LHivPa cohorts, NAFLD was diagnosed if the controlled attenuation parameter (CAP) was ≥ 248 dB/m; in the MHMC cohort, it was diagnosed if the liver/spleen Hounsfield unit (HU) ratio on abdominal computerized tomography scan was < 1.1. Medium/high‐risk fibrosis category was defined as fibrosis‐4 (FIB‐4) ≥ 1.30. Patients requiring specialist referral to hepatology were defined as either having NAFLD and being in the medium/high‐risk fibrosis category or having elevated alanine aminotransferase (ALT).
Results
A total of 1534 HIV‐infected adults without significant alcohol intake or viral hepatitis coinfection were included in the study. Of these, 313 (20.4%) patients had the metabolic comorbidities (obesity and/or diabetes) required for entry in the diagnostic algorithm. Among these patients, 123 (39.3%) required specialist referral to hepatology, according to guidelines. A total of 1062 patients with extended metabolic comorbidities (any among obesity, diabetes, hypertension and dyslipidaemia) represented most of the cases of NAFLD (79%), elevated ALT (75.9%) and medium/high‐risk fibrosis category (75.4%). When the algorithm was extended to these patients, it was found that 341 (32.1%) would require specialist referral to hepatology.
Conclusions
According to current guidelines, one in five HIV‐monoinfected patients should undergo detailed assessment for NAFLD and disease severity. Moreover, one in ten should be referred to hepatology. Expansion of the algorithm to patients with any metabolic comorbidities may be considered.
Summary
Lower 25‐hydroxyvitamin D 25(OH)D serum levels have been associated with the severity of liver fibrosis in genotype 1 chronic hepatitis C patients (G1CHC). In addition, a recent genome‐wide ...study identified genetic variants (rs12785878, near dehydrocholesterol reductase, DHCR7; rs10741657, near CYP2R1; and rs7041, near vitamin D‐binding protein, GC) affecting 25(OH)D serum levels in healthy populations. We aimed to assess the association between vitamin D serum levels and its genetic determinants, with the severity of liver fibrosis. Two hundred and sixty patients with biopsy‐proven G1CHC were consecutively evaluated. The 25(OH)D serum levels were measured by high‐pressure liquid chromatography. All patients were genotyped for DHCR7 rs12785878, CYP2R1 rs10741657 and GC rs7041 single nucleotide polymorphisms. DHCR7 GG genotype (P = 0.003) and the severity of fibrosis (P = 0.03) were independent factors associated with lower 25(OH)D serum levels in multiple linear regression analysis. Interestingly, 53.8% (7/13) of patients with DHCR7 GG genotype had severe liver fibrosis, compared to 27.1% (67/247) of those with DHCR7 TT/TG genotype (P = 0.03). By multivariate logistic regression analysis, severe fibrosis was independently associated with older age (OR, 1.056; 95% CI, 1.023–1.089, P = 0.001), low cholesterol (OR, 0.984; 95% CI, 0.974–0.994, P = 0.002), high triglycerides (OR, 1.008; 95% CI, 1.002–1.015, P = 0.01), low 25(OH)D (OR, 0.958; 95% CI, 0.919–0.999, P = 0.04), DHCR7 GG genotype (OR, 4.222; 95% CI, 1.106–16.120; P = 0.03), moderate–severe steatosis (OR, 2.588; 95% CI, 1.355–4.943; P = 0.004) and moderate–severe necroinflammatory activity (grading) (OR, 2.437; 95% CI, 1.307–4.763; P = 0.001). No associations were found between liver fibrosis and both CYP2R1 and GC genotypes. In patients with G1CHC, GG homozygosis for DHCR7 gene and lower 25(OH)D levels are independently associated with the severity of liver fibrosis.
Summary
Background
The PNPLA3/Adiponutrin rs738409 C/G single nucleotide polymorphism is associated with the severity of steatosis, steatohepatitis and fibrosis in patients with non‐alcoholic fatty ...liver disease, as well as the severity of steatosis and fibrosis in patients with chronic hepatitis C (CHC).
Aim
To test in genotype 1(G1)‐CHC patients, the putative association between the PNPLA3 variant and histological features of steatohepatitis, as well as their impact on the severity of fibrosis.
Methods
Four hundred and thirty‐four consecutively biopsied Caucasian G1‐CHC patients were genotyped for PNPLA3 rs738409, its effect evaluated by using an additive model. Histological features of steatohepatitis in CHC were assessed using the Bedossa classification. Hepatic expression of PNPLA3 mRNA was evaluated in 63 patients.
Results
The prevalence of steatohepatitis increased from 16.5% in patients with PNPLA3 CC, to 23.2% in CG and 29.2% in the GG genotype (P = 0.02). By multiple logistic regression, PNPLA3 genotype (OR 1.54, 95% CI 1.03–2.30, P = 0.03), together with age (OR 1.03, 95% CI 1.00–1.05, P = 0.02), BMI ≥ 30 (OR 2.06, 95% CI 1.04–4.10, P = 0.03) and homoeostasis model assessment (HOMA, OR 1.18, 95% CI 1.04–1.32, P = 0.006) were independently linked to steatohepatitis. When stratifying for obesity, PNPLA3 was associated with NASH in non‐obese patients only (12.0% in CC vs. 18.3% in CG vs. 27.3% in GG, P = 0.01), including after correction for metabolic confounders (OR 2.06, 95% CI 1.26–3.36, P = 0.004). We showed an independent association between steatohepatitis (OR 2.05, 95% CI 1.05–4.02, P = 0.003) and severe fibrosis. Higher liver PNPLA3 mRNA was associated both with the severity of steatosis (adjusted P = 0.03) and steatohepatitis after adjusting for gender, age, BMI and HOMA (P = 0.002).
Conclusion
In patients with genotype 1 hepatitis C, the PNPLA3 G variant is associated with a higher risk of steatosis severity and steatohepatitis, particularly among non‐obese subjects.
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