Evaluation of the immune response to pneumococcal capsular polysaccharides

Inflammatory markers and cardiometabolic diseases

OBJECTIVES

A growing body of evidence emerges that obesity, metabolic syndrome, type 2 diabetes and cardiovascular disease are intimately related to chronic inflammation.

METHODS

A narrative review summarizing the most recent data of the literature describing the pathological implications of inflammation in obese patients with cardiometabolic disorders.

RESULTS

Besides high-sensitive C-reactive protein, various circulating or in situ inflammatory markers have been identified, presumably reflecting the presence of inflammation in various key-organs (visceral adipose tissue, skeletal muscle, pancreatic islets, liver, intestine, arterial wall). Available data support the concept that targeting inflammation, not only reduces systemic inflammatory markers, but also improves insulin sensitivity and ameliorates glucose control in insulin-resistant patients, thus potentially reducing the risk of cardiovascular complications.

CONCLUSION

These observations confirm the role of inflammation in cardiometabolic diseases and support the development of pharmacological strategies that aim at reducing inflammation, especially in patients with type 2 diabetes.

Ursodeoxycholic acid dose-dependently improves liver injury in rats fed a methionine- and choline-deficient diet

AIM

  The data on the beneficial effect of ursodeoxycholic acid (UDCA) in non-alcoholic steatohepatitis (NASH) are controversial. The difference of opinion is connected with UDCA dosage to be used. Therefore, we evaluated the dose-dependent efficacy of UDCA in experimental NASH.

METHODS

  Male Wistar rats were fed the methionine- and choline-deficient (MCD) diet for 10 weeks. Rats were administrated UDCA (10, 20, 40 and 80 mg/kg bodyweight intragastrically) after 6 weeks of the MCD diet.

RESULTS

  Animals fed the MCD diet developed severe steatohepatitis. Treatment with UDCA dose-dependently decreased liver damage, but only high-dose UDCA (80 mg/kg) significantly diminished ultrastructural changes in addition to preventing steatosis, ballooning and inflammatory changes in the liver. The activities of serum marker enzymes and the content of liver triglyceride and blood glucose were increased in MCD diet-fed rats, but decreased in all the UDCA-treated groups. Serum insulin concentration was decreased whereas the quantitative insulin sensitivity check index did not changed in MCD diet-fed groups. Serum tumor necrosis factor-α content was strongly increased after MCD diet and normalized in the UDCA-treated rats, with the most pronounced effect in the highest dose groups, 40 and 80 mg/kg. The contents of endogenous ethanol in blood and intestinal mucus were increased in MCD diet-fed rats which were significantly lowered by UDCA (40 and 80 mg/kg per day).

CONCLUSION

  The present data demonstrate a beneficial effect of UDCA that manifested by the decrease of liver steatosis, inflammatory signs and serum tumor necrosis factor-α content especially of the highest 40 and 80 mg/kg day doses.

Open-labeled pilot study of cysteine-rich whey protein isolate supplementation for nonalcoholic steatohepatitis patients

BACKGROUND AND AIMS

Glutathione (GSH) depletion contributes to liver injury and development of steatohepatitis. Undenatured cysteine-rich whey protein isolate has been clinically proven to raise GSH in several patient groups. The aim of this study was to evaluate the effect of oral supplementation with whey protein on patients with nonalcoholic steatohepatitis (NASH).

METHODS

In an open-labeled clinical trial, 38 patients (18 male, 20 female; mean age 48 +/- 14 years) with NASH confirmed by computed tomography measurements and liver biochemistries were given with a daily dose of 20 g whey protein isolate for 12 weeks.

RESULTS

A significant reduction in alanine aminotransferase (ALT) (64 +/- 72 vs 46 +/- 36, P = 0.016) and aspartate aminotransferase (AST) (45 +/- 49 vs 33 +/- 18, P = 0.047) were observed. Plasma glutathione and total antioxidant capacity increased significantly at the end of study (53 +/- 11 vs 68 +/- 11, P < 0.05 and 1.26 +/- 0.10 vs 2.03 +/- 0.10, P < 0.05). Liver attenuation index improved from -13.4 +/- 11.1 to -9.7 +/- 13.1 (P = 0.048). Hepatic macrovesicular steatosis decreased significantly after 12 weeks of supplementation (33.82 +/- 12.82 vs 30.66 +/- 15.96, P = 0.046). Whey protein isolate was well tolerated. No serious adverse events were observed.

CONCLUSIONS

The results indicate that oral supplementation of cysteine-rich whey protein isolate leads to improvements in liver biochemistries, increased plasma GSH, total antioxidant capacity and reduced hepatic macrovesicular steatosis in NASH patients. The results support the role of oxidative stress in the pathogenesis of this disease.

Liver mitochondrial dysfunction and oxidative stress in the pathogenesis of experimental nonalcoholic fatty liver disease

Oxidative stress and hepatic mitochondria play a role in the pathogenesis of nonalcoholic fatty liver disease. The aim of the present study was to evaluate the role of hepatic mitochondrial dysfunction and oxidative stress in the pathogenesis of the disease. Fatty liver was induced in Wistar rats with a choline-deficient diet (CD; N = 7) or a high-fat diet enriched with PUFAs-omega-3 (H; N = 7) for 4 weeks. The control group (N = 7) was fed a standard diet. Liver mitochondrial oxidation and phosphorylation were measured polarographically and oxidative stress was estimated on the basis of malondialdehyde and glutathione concentrations. Moderate macrovacuolar liver steatosis was observed in the CD group and mild liver steatosis was observed in the periportal area in the H group. There was an increase in the oxygen consumption rate by liver mitochondria in respiratory state 4 (S4) and a decrease in respiratory control rate (RCR) in the CD group (S4: 32.70 +/- 3.35; RCR: 2.55 +/- 0.15 ng atoms of O2 min-1 mg protein-1) when compared to the H and control groups (S4: 23.09 +/- 1.53, 17.04 +/- 2.03, RCR: 3.15 +/- 0.15, 3.68 +/- 0.15 ng atoms of O2 min-1 mg protein-1, respectively), P < 0.05. Hepatic lipoperoxide concentrations were significantly increased and the concentration of reduced glutathione was significantly reduced in the CD group. A choline-deficient diet causes moderate steatosis with disruption of liver mitochondrial function and increased oxidative stress. These data suggest that lipid peroxidation products can impair the flow of electrons along the respiratory chain, causing overreduction of respiratory chain components and enhanced mitochondrial reactive oxygen species. These findings are important in the pathogenesis of nonalcoholic fatty liver disease.

Severity of liver echogenicity is correlated to serum c-peptide levels in type 2 diabetic patients

AIM

To investigate the correlation between liver echogenicity and serum C-peptide levels in type 2 diabetic patients treated with oral hypoglycaemic agents.

PATIENTS AND METHODS

The study included 231 type 2 diabetic patients (114 men) with a mean age of 64.3 +/- 6.9 years and a mean diabetes duration of 8.5 +/- 3.2 years. Liver echogenicity was graded by ultrasound examination as follows: Grade 0 (normal liver texture), grade 1 (slight increase of liver echogenicity), grade 2 (moderate increase of liver echogenicity with impaired visualization of intrahepatic vessels and right hemi-diaphragm), grade 3 (marked increase of liver echogenicity with very poor visualization or non-visualization of intrahepatic vessels and right hemi-diaphragm). Serum C-peptide was measured both in fasting state (Fasting C-peptide, FCP) and after glucagon administration (Glucagon-stimulated C-peptide, GCP).

RESULTS

FCP (median; interquartile range) showed a significant difference (p=0.041) between patients with grade 0 (1.9 ng/dl; 1.1-2.7 ng/dl),grade 1 (2.7 ng/dl; 1.9-3.7 ng/dl), grade 2 (4.1 ng/dl; 2.6-5.1 ng/dl) and grade 3 (6.2 ng/dl; 4.6-7.5 ng/dl) liver echogenicity. GCP (median; interquartile range) also differed significantly (p=0.04) between patients with grade 0 (2.6 ng/dl; 1.8-3.3 ng/dl), grade 1 (4.3 ng/dl; 3.3-5 ng/dl), grade 2 (5.8 ng/dl; 4.6-6.9 ng/dl) and grade 3 (8.3 ng/dl; 6.6-9.5 ng/dl) liver echogenicity. In multiple regression analysis, both FCP and GCP showed significant (p < 0.05) positive correlations with waist circumference, triglycerides, WHR and liver echogenicity.

CONCLUSIONS

In type 2 diabetic patients treated with oral hypoglycaemic agents, liver echogenicity shows a significant positive correlation with serum C-peptide levels, both in fasting state and after glucagon administration.

Nonalcoholic fatty liver disease: a review of current understanding and future impact

Nonalcoholic fatty liver disease (NAFLD), already the most common form of liver disease in the United States, can be expected to increase in prevalence and severity in parallel with national epidemics of obesity and type 2 diabetes. NAFLD is frequently associated with insulin resistance. While insulin resistance, and thereby hyperinsulinemia, are, in large part, metabolic consequences of obesity, the basis of diversity in severity and progression of inflammation and fibrosis is not known. Increased susceptibility to oxidative stress is likely to play a role. Several patient characteristics have been associated with more severe histological findings in patients with NAFLD, including type 2 diabetes, hypertension, age over 40 years, and higher transaminases. Liver biopsy is, however, required to accurately grade and stage NAFLD histologically. Although the natural history of NAFLD is relatively poorly defined, NAFLD is increasingly recognized as an important cause of decompensated liver disease. Weight reduction and improved insulin sensitivity are associated with improved biochemical and histological parameters of NAFLD. There are, however, no proven safe and efficacious pharmacological treatments for NAFLD.