To perform or not to perform liver biopsy: an alternative view

Systematic review and meta-analysis of controlled intervention studies on the effectiveness of long-chain omega-3 fatty acids in patients with nonalcoholic fatty liver disease

Context

Treatment options for nonalcoholic fatty liver disease (NAFLD) are needed.

Objective

The aim of this review was to systematically assess the effects of omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs), particularly eicosapentaenoic acid and docosahexaenoic acid, on liver-related and metabolic outcomes in adult and pediatric patients with NAFLD.

Data Sources

The online information service ProQuest Dialog was used to search 8 literature databases.

Study Selection

Controlled intervention studies in which the independent effects of n-3 LC-PUFAs could be isolated were eligible for inclusion.

Data Extraction

The 18 unique studies that met the criteria for inclusion were divided into 2 sets, and data transcriptions and study quality assessments were conducted in duplicate. Each effect size was expressed as the weighted mean difference and 95%CI, using a random-effects model and the inverse of the variance as a weighting factor.

Results

Based on the meta-analyses, supplementation with n-3 LC-PUFAs resulted in statistically significant improvements in 6 of 13 metabolic risk factors, in levels of 2 of 3 liver enzymes, in liver fat content (assessed via magnetic resonance imaging/spectroscopy), and in steatosis score (assessed via ultrasonography). Histological measures of disease [which were assessed only in patients with nonalcoholic steatohepatitis (NASH)] were unaffected by n-3 LC-PUFA supplementation.

Conclusions

Omega-3 LC-PUFAs are useful in the dietary management of patients with NAFLD. Additional trials are needed to better understand the effects of n-3 LC-PUFAs on histological outcomes in patients with NASH.

Systematic Review Registration

PROSPERO CRD42017055951.

Validity of ultrasonography to assess hepatic steatosis compared to magnetic resonance spectroscopy as a criterion method in older adults

Background

The rising prevalence of obesity has made hepatic steatosis an increasingly common issue. Ultrasound is generally used in clinical practice to assess steatosis, but its accuracy has been inconsistent across studies. We aimed to determine the validity of ultrasound to diagnose hepatic steatosis when compared to the criterion method proton magnetic resonance spectroscopy (MRS) in older individuals.

Methods

A total of 72 healthy white European individuals (n = 42 men; n = 30 women aged 67–76 years) participating in the Hertfordshire Birth Cohort Physical Activity trial had hepatic steatosis assessed by ultrasound and MRS. The ultrasound scans were graded as normal, mild, moderate and severe steatosis, while hepatic fat content above 5.5% by MRS was used as a cut-off for steatosis.

Results

18 participants (25%) had a level of hepatic fat measured by MRS consistent with diagnosis of steatosis. The sensitivity and specificity of ultrasound in diagnosing hepatic steatosis (mild/moderate/severe vs normal) were 96% (95% CI: 87–99.6%) and 94% (95% CI: 73–100%) respectively, although overlap in MRS hepatic fat content was observed between the ultrasound categories.

Conclusions

Ultrasound is a valid method for detecting the presence or absence of hepatic steatosis in older adults and can be used as an alternative tool in both clinical investigations and epidemiological studies, when other imaging techniques are not feasible.

Hereditary hemochromatosis restores the virulence of plague vaccine strains

Nonpigmented Yersinia pestis (pgm) strains are defective in scavenging host iron and have been used in live-attenuated vaccines to combat plague epidemics. Recently, a Y. pestis pgm strain was isolated from a researcher with hereditary hemochromatosis who died from laboratory-acquired plague. We used hemojuvelin-knockout (Hjv(-/-)) mice to examine whether iron-storage disease restores the virulence defects of nonpigmented Y. pestis. Unlike wild-type mice, Hjv(-/-) mice developed lethal plague when challenged with Y. pestis pgm strains. Immunization of Hjv(-/-) mice with a subunit vaccine that blocks Y. pestis type III secretion generated protection against plague. Thus, individuals with hereditary hemochromatosis may be protected with subunit vaccines but should not be exposed to live-attenuated plague vaccines.

Fibronectin: Functional character and role in alcoholic liver disease

Fibronectins are adhesive glycoproteins that can be found in tissue matrices and circulating in various fluids of the body. The variable composition of fibronectin molecules facilitates a diversity of interactions with cell surface receptors that suggest a role for these proteins beyond the structural considerations of the extracellular matrix. These interactions implicate fibronectin in the regulation of mechanisms that also determine cell behavior and activity. The two major forms, plasma fibronectin (pFn) and cellular fibronectin (cFn), exist as balanced amounts under normal physiological conditions. However, during injury and/or disease, tissue and circulating levels of cFn become disproportionately elevated. The accumulating cFn, in addition to being a consequence of prolonged tissue damage, may in fact stimulate cellular events that promote further damage. In this review, we summarize what is known regarding such interactions between fibronectin and cells that may influence the biological response to injury. We elaborate on the effects of cFn in the liver, specifically under a condition of chronic alcohol-induced injury. Studies have revealed that chronic alcohol consumption stimulates excess production of cFn by sinusoidal endothelial cells and hepatic stellate cells while impairing its clearance by other cell types resulting in the build up of this glycoprotein throughout the liver and its consequent increased availability to influence cellular activity that could promote the development of alcoholic liver disease. We describe recent findings by our laboratory that support a plausible role for cFn in the promotion of liver injury under a condition of chronic alcohol abuse and the implications of cFn stimulation on the pathogenesis of alcoholic liver disease. These findings suggest an effect of cFn in regulating cell behavior in the alcohol-injured liver that is worth further characterizing not only to gain a more comprehensive understanding of the role this reactive glycoprotein plays in the progression of injury but also for the insight further studies could provide towards the development of novel therapies for alcoholic liver disease.

Fatty liver and transaminase changes with adjuvant tamoxifen therapy

We investigated the time it took to develop fatty liver and changes in serum aspartate aminotransferase and alanine aminotransferase levels in patients with breast cancer treated with adjuvant tamoxifen. Liver sonography to detect fatty liver and measurement of serum aspartate and alanine aminotransferase levels were performed regularly for patients with early breast cancer. The results were compared in groups of patients with and without adjuvant tamoxifen as well as those on chemotherapy. Eighty-two of 156 patients treated with tamoxifen developed fatty liver, compared with eight of 62 patients not taking it. Fatty liver appeared as early as 3 months after beginning tamoxifen and was detected within 2 years in most cases. It persisted for 48 months after discontinuing tamoxifen in 17 of the 82 patients who developed it. The incidence of fatty liver in patients receiving both chemotherapy and tamoxifen was the same as that in patients receiving tamoxifen alone. While 115 patients had elevations of aspartate aminotransferase, alanine aminotransferase or both, the magnitude of the elevation was clinically significant in only 32 patients. Patients on both chemotherapy and tamoxifen had a higher incidence of elevated transaminases than those on tamoxifen alone. Adjuvant tamoxifen increases the incidence of fatty liver, but has only a minimal effect on aspartate aminotransferase and alanine aminotransferase. Fatty liver may appear as early as 3 months after beginning tamoxifen and may persist for more than 4 years after discontinuing it. Therefore, long-term follow-up is warranted. Chemotherapy is not clearly associated with fatty liver, but may cause a greater degree of hepatocellular damage than does tamoxifen.

Prolonged n-3 polyunsaturated fatty acid supplementation ameliorates hepatic steatosis in patients with non-alcoholic fatty liver disease: a pilot study

BACKGROUND

Recent studies suggest a role of n-3 long-chain polyunsaturated fatty acids (n-3 PUFA) as peroxisome proliferator-activated receptor-alpha ligands in improving non-alcoholic fatty liver disease (NAFLD) in rodents. However, data in humans are still lacking.

AIM

To evaluate the efficacy of prolonged PUFA supplementation in patients with NAFLD.

METHODS

Fifty-six patients with NAFLD were enrolled. Among the overall eligible patients, 42 assumed n-3 PUFA 1-g capsule daily for 12 months, whereas 14 refused the treatment and were analysed as controls. All patients underwent haematochemical and ultrasound follow-up.

RESULTS

Polyunsaturated fatty acid supplementation significantly decreased serum aspartate transaminase (P = 0.003), alanine transaminase (P = 0.002), gamma-glutamyl transpeptidase (P = 0.03), triglycerides (P = 0.02) and fasting glucose (P = 0.02) in comparison with controls. Circulating arachidonate and n-6/n-3 fatty acid ratio was reduced (P = 0.0002, and P = 0.0001 respectively) in treated patients. Moreover, ultrasonography demonstrated improvement of liver echotexture after PUFA (P = 0.0001), and increase of Doppler perfusion index (P = 0.001), whereas no significant changes occurred in controls.

CONCLUSIONS

Supplementation with n-3 PUFA improves biochemical, ultrasonographic and haemodynamic features of liver steatosis. Our study supports the efficacy of n-3 PUFA as a new therapeutic approach in the treatment of NAFLD.

High prevalence of metabolic complications in patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is considered to be the liver component of the metabolic syndrome and is frequently associated with obesity, dyslipidemia and type II diabetes mellitus (NIDDM). We aimed to determine the development of liver function tests (LFTs) and metabolic complications in patients previously diagnosed with NAFLD.

METHODS

One-hundred-and-two patients with NAFLD diagnosed in the period 1994-2001 were identified. Eighty were brought in for new investigations, including LFTs, blood pressure, BMI, lipid profile, blood glucose and insulin. Original liver biopsy was re-evaluated.

RESULTS

Sixty-two patients (77%) were males (median age 46 years; mean follow-up time 2.8 +/- 1.2 years). Fifty-four patients (68%) were light to moderately overweight with body mass index (BMI) 25-30 kg/m. Mean BMI (28.2) was the same at diagnosis and at follow-up (28.3). At the new examination, 18 patients (23%) had developed diabetes mellitus type II (n = 6) or had impaired fasting glucose (IFG) (n = 12), compared to only 2 patients at diagnosis. Hyperinsulinemia was observed in 19 patients (24%). Dyslipidemia, with elevated triglycerides and/or hypercholesterolemia, was now present in 65 patients (81%). Twenty-two patients (27%) had hypertension compared to 9 (11%) at diagnosis. Liver biopsy was performed in 24%, and 89% of those fulfilled the criteria for NASH. However, mild inflammation and fibrosis was observed, grade 1-2 (n = 17), stage I-II (n = 13) and none had cirrhosis.

CONCLUSION

A significant proportion of patients with both clinical and histological diagnosis of NAFLD develop metabolic problems soon after diagnosis. These patients should be screened regularly for metabolic disorders.