Red blood cell antioxidant and iron status in alcoholic and nonalcoholic cirrhosis

Alcoholic liver disease: Clinical and translational research

The present review spans a broad spectrum of topics dealing with alcoholic liver disease (ALD), including clinical research, translational research, pathogenesis and therapies. A special accent is placed on alcohol misuse, as alcohol is a legally commercialized and taxable product. Drinking alcohol, particularly from a young age, is a major health problem. Alcoholism is known to contribute to morbidity and mortality. A systematic literature search was performed in order to obtain updated data (2008-2015). The review is focused on genetic polymorphisms of alcohol metabolizing enzymes and the role of cytochrome p450 2E1 and iron in ALD. Alcohol-mediated hepatocarcinogenesis is also discussed in the presence or absence of co-morbidities such as viral hepatitis C as well as therapeutic the role of innate immunity in ALD-HCV. Moreover, emphasis was placed on alcohol and drug interactions, as well as liver transplantation for end-stage ALD. Finally, the time came to eradicate alcohol-induced liver and intestinal damage by using betaine.

Antioxidative status of patients with alcoholic liver disease in southeastern Taiwan

AIM: To investigate the antioxidative status of patients with alcoholic liver disease (ALD) in southeastern Taiwan.

METHODS: Our study comprised 27 patients with ALD recruited from Taitung Mackay Memorial Hospital, located in southeastern Taiwan. Patients with ALD included 12 non-aborigines (12 men) and 15 aborigines (11 men and 4 women). According to the severity of ALD, patients with ALD included 10 with hepatitis (9 men and 1 woman) and 17 with cirrhosis (14 men and 3 women). Twenty-two age- and gender-matched healthy adults served as the control group in this study. Venous blood (10 mL) of each subject was drawn into EDTA-containing tubes after 8 h overnight fasting.

RESULTS: Compared to the control group, patients with ALD showed significantly lower erythrocytic catalase (11.1 ± 0.7 U/mg Hb vs 8.0 ± 0.7 U/mg Hb, P < 0.05) and superoxide dismutase (9.5 ± 1.6 U/mg Hb vs 3.0 ± 0.2 U/mg Hb, P < 0.05) activities. Furthermore, the erythrocytic reduced glutathione/oxidized glutathione ratio was significantly lower in ALD patients than that in the control group (38.1 ± 5.4 vs 15.7 ± 1.9, P < 0.05). The results revealed that patients with ALD experienced more oxidative stress than those in the control group. The non-aboriginal, but not the aboriginal, ALD group had higher erythrocytic glutathione peroxidase (GPX) activity than that in the control group (46.1 ± 7.8 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05). Hepatitis, but not cirrhosis, ALD patients had higher erythrocytic GPX activity than that in the control group (44.3 ± 8.6 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05).

CONCLUSION: Our results indicate that both ethnicity and the severity of ALD may cause different erythrocytic antioxidative enzyme activities especially GPX activity.

Deficiency in calcineurin activity in liver transplantation candidates with alcoholic cirrhosis or hepatocellular carcinoma

BACKGROUND

Tacrolimus and cyclosporin inhibits the activity of calcineurin, a serine/threonine phosphatase that is involved in many physiological and pathological pathways. However, the baseline calcineurin phosphatase activity (CPA) measured before the transplant is unknown. In this study, we determine baseline CPA in liver transplant (LT) candidates and explore some factors that might modify it.

PATIENTS AND METHODS

Thirty-two consecutive LT candidates (25 men, seven women, average age 53.4 years) were included. Seven millilitres of whole blood was collected from each patient. CPA was determined in lymphocytes quantifying a dephosphorylated peptide phosphorylated previously (D-L-D-V-P-I-P-G-R-F-D-R-R-V-S-V-A-A-E) by high-performance liquid chromatography. The relationship between CPA and the quantitative variables was tested according to Pearson's correlation. A two-way analysis of variance was performed to test the independent role of categorical parameters in CPA.

RESULTS

The median CPA was significantly lower in LT candidates than in healthy volunteers [179.2 (146.9-226.3) vs 247.8 (220.9-292.5) pmol/min/10(6) peripheral blood mononuclear cell (PBMC), respectively, P=0.0002]. CPA was also significantly lower in alcoholic cirrhosis (152.2 vs 211.1 pmol/min/10(6) PBMC, P=0.04) and in the presence of hepatocellular carcinoma (HCC) (152.0 vs 213.5 pmol/min/10(6) PBMC, P=0.0074) compared with other liver diseases. A two-way analysis of variance showed that these parameters were independently associated with lower CPA (P=0.05 for alcohol and P=0.0056 for HCC respectively).

CONCLUSION

This pilot study showed a lower CPA in patients with AC and HCC. This phenomenon may contribute towards lowering the risk of acute rejection in these patients after LT and, on the other hand, may increase the risk of de novo cancers.

Altered expression of iron regulatory genes in cirrhotic human livers: clues to the cause of hemosiderosis?

Hepatic iron deposition unrelated to hereditary hemochromatosis occurs commonly in cirrhosis but the pathogenesis of this condition is unknown. The aim of this study was to compare the expression of genes involved in the regulation of iron metabolism in cirrhotic (n=22) and control human livers (n=5). Transcripts were quantitated by real-time RT-PCR and protein levels were assessed by western blot. Hepatic iron concentrations (HICs) were measured by a spectrophotometric method. Levels of hepcidin mRNA did not differ between controls and cirrhotic livers; there was a highly significant correlation between hepcidin transcript levels and HIC in the latter group. Ferroportin, divalent metal transporter-1 (DMT1), and ferritin heavy chain mRNA levels were significantly higher in cirrhotic human livers than in controls (P=0.007, 0.039, and 0.025, respectively). By western blot, ferroportin and DMT1 levels were generally diminished in the cirrhotic livers compared to controls; neither correlated with HIC. In contrast, the abundance of ferritin increased with increasing HIC in the cirrhotic livers, whereas transferrin receptor decreased, indicating physiologically appropriate regulation. In conclusion, hepcidin expression appears to be appropriately responsive to iron status in cirrhosis. However, there are complex alterations in DMT1 and ferroportin expression in cirrhotic liver, including decreases in ferroportin and DMT1 at the protein level that may play a role in aberrant regulation of iron metabolism in cirrhosis.

Results of an international round robin for the quantification of serum non-transferrin-bound iron: Need for defining standardization and a clinically relevant isoform

Non-transferrin-bound iron (NTBI) appears in the circulation of patients with iron overload. Various methods to measure NTBI were comparatively assessed as part of an international interlaboratory study. Six laboratories participated in the study, using methods based on iron mobilization and detection with iron chelators or on reactivity with bleomycin. Serum samples of 12 patients with hereditary (n=11) and secondary (n=1) hemochromatosis were measured during a 3-day analysis using 4 determinations per sample per day, making a total of 144 measurements per laboratory. Bland-Altman plots for repeated measurements are presented. The methods differed widely in mean serum NTBI level (range 0.12-4.32mumol/L), between-sample variation (SD range 0.20-2.13mumol/L and CV range 49.3-391.3%), and within-sample variation (SD range 0.02-0.45mumol/L and CV range 4.4-193.2%). The results obtained with methods based on chelators correlated significantly (R(2) range 0.86-0.99). On the other hand, NTBI values obtained by the various methods related differently from those of serum transferrin saturation (TS) when expressed in terms of both regression coefficients and NTBI levels at TS of 50%. Recent studies underscore the clinical relevance of NTBI in the management of iron-overloaded patients. However, before measurement of NTBI can be introduced into clinical practice, there is a need for more reproducible protocols as well as information on which method best represents the pathophysiological phenomenon and is most pertinent for diagnostic and therapeutic purposes.

Antioxidant levels in peripheral blood, disease activity and fibrotic stage in chronic hepatitis C

BACKGROUND

This study addressed the suggested association between levels of the antioxidants glutathione (GSH), vitamin C and vitamin E in peripheral blood and the histological activity and fibrosis stage in chronic hepatitis C (CHC). We then determined whether regular antioxidant supplementation influenced these antioxidant levels or disease severity.

METHODS

Clinical, biochemical, histological and demographic data were collected from 247 CHC patients at the time of liver biopsy. Whole blood total GSH, plasma vitamin C and E were assessed by high-performance liquid chromatography. Statistical analyses were performed to test for associations between the variables and to identify independent predictors for hepatic necroinflammatory and fibrosis scores.

RESULTS

GSH and vitamin C, but not vitamin E correlated with both portal/periportal activity (r = -0.19, P = 0.004; r = -0.19, P = 0.009 respectively) and fibrosis stage (r = -0.18, P = 0.007; r = -0.18, P = 0.009 respectively). GSH was an independent negative predictor of portal/periportal inflammation (P = 0.02) and fibrosis (P = 0.01). Vitamin C was an independent negative predictor of fibrosis stage (P = 0.02). Antioxidant intake was associated with higher vitamin C (P < 0.0001) and vitamin E (P = 0.005) levels, but not GSH.

CONCLUSIONS

Whole blood GSH and plasma vitamin C are negatively associated with hepatic portal/periportal inflammation and fibrosis stage in CHC. Controlled intervention studies with vitamin C and agents that boost endogenous GSH levels are warranted.

Plasma phosphatidylcholine hydroperoxide as a new marker of oxidative stress in alcoholic patients

Quantitative analysis of plasma phosphatidylcholine hydroperoxide (PCOOH) is an important step in evaluating the biochemical processes leading to oxidative injury. However, secondary products of lipid peroxidation are now used as indices. One hundred nine alcoholic patients, aged 22-81 years (mean +/- SEM, 52.0 +/- 1.3 years), and 21 healthy volunteers, aged 41-79 years (51.2 +/- 2.2 years), participated in this study. Plasma PCOOH was measured by HPLC with chemiluminescence detection. Plasma PCOOH concentration was significantly higher in alcoholic patients (46.1 +/- 4.1 pmol/ml) than in controls (15.6 +/- 1.8 pmol/ml). It was significantly higher in patients with blood alcohol (88.0 +/- 10.5 pmol/ml) than in those without alcohol (32.6 +/- 3.1 pmol/ml). The patients with high levels of aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase (gamma-GTP), and triglyceride (TG) showed significantly higher PCOOH concentrations than did patients with normal levels. The PCOOH level was positively correlated with levels of gamma-GTP, HDL, blood alcohol concentration, and TG. Plasma PCOOH levels in 29 alcoholic patients after a 6 week abstinence were decreased significantly (22.8 +/- 11.1 pmol/ml), which was associated with improvement on liver function tests. This is the first measurement of plasma PCOOH in alcoholic patients. These results suggest the involvement of lipid peroxidation in alcohol-induced liver damage and confirm that the PCOOH plasma concentration is a new marker of alcohol consumption as well as oxidative stress in alcoholic patients.

Changes of hepatic fibrosis induced by iron overload in SD rats

AIM: To study the histological changes of hepatic fibrosis induced by diet iron overload in SD rats.

METHODS: After living on an iron overload in diet for 63 d, the male SD rats were decollated and the livers were harvested to examine the liver indexes, morphology of hepatocytes, hepatic stellate cells (HSC), sinusoidal endothelial cells, sinusoid, peri-sinusoid, and distribution of collagen type III and laminin were also observed.

RESULTS: On model rats there were coagulation necrosis of hepatocytes, activated HSC, sinusoidal endothelial cells with less fenestrae, sinusoidal capillarization and light peri-sinusoid fibrosis, thickened basement of central vein, more collagen types I and II and laminin than those in normal controls.

CONCLUSION: Iron overload in diet for some time can injure hepatocytes, activate HSC, decrease the fenestrae of sinusoidal endothelial cell, and result in sinusoidal capillarization and peri-sinusoid fibrosis. It may be feasible to establish an ALD model with iron overload in diet.

Effects of different operations on cirrhotic portal hypertensive liver in rats

AIM: To evaluate respectively the effects of portaazygous disconnection (PAD), mesocaval shunt (MCS) and distal splenocaval shunt (DSCS) on the portasytemic shunting (PSS), hepatic function (HF), hepatic mitochondrial respiratory function (HMRF) and its ultrastructure, anti-oxidation ability (HAOA) and lipoperoxide (LPO), so as to provide theoretical basis to select a suitable operation.

METHODS: Using the cirrhotic portal hypertensive model induced by CCl₄/ethanol in Wristar rats, we investigated PSS, HF, HMRF and its HAOA and LPO during three wks after MCS, DSCS and PAD.

RESULTS: After MCS, the PSS were further increased, HF, HMRF and HAOA were significantly decreased, and LPO increased. Hepatic mitochondrial ultrastructure showed severely damaged. Only a little improvement was found on the third wk. After DSCS and PAD, above mentioned indexes were less influenced, and they were restored a little more quickly in DSCS groups than that in PAD groups. During the first postoperative wk, the PAD group showed the highest mortality.

CONCLUSION: DSCS may be a desirable operation among the three kinds of operation.

Pathogenesis and management of alcoholic hepatitis

Alcoholic hepatitis is a potentially life-threatening complication of alcoholic abuse, typically presenting with symptoms and signs of hepatitis in the presence of an alcohol use disorder. The definitive diagnosis requires liver biopsy, but this is not generally required. The pathogenesis is uncertain, but relevant factors include metabolism of alcohol to toxic products, oxidant stress, acetaldehyde adducts, the action of endotoxin on Kupffer cells, and impaired hepatic regeneration. Mild alcoholic hepatitis recovers with abstinence and the long-term prognosis is determined by the underlying disorder of alcohol use. Severe alcoholic hepatitis is recognized by a Maddrey discriminant function >32 and is associated with a short-term mortality rate of almost 50%. Primary therapy is abstinence from alcohol and supportive care. Corticosteroids have been shown to be beneficial in a subset of severely ill patients with concomitant hepatic encephalopathy, but their use remains controversial. Pentoxifylline has been shown in one study to improve short-term survival rates. Other pharmacological interventions, including colchicine, propylthiouracil, calcium channel antagonists, and insulin with glucagon infusions, have not been proven to be beneficial. Nutritional supplementation with available high-calorie, high-protein diets is beneficial, but does not improve mortality. Orthotopic liver transplantation is not indicated for patients presenting with alcoholic hepatitis who have been drinking until the time of admission, but may be considered in those who achieve stable abstinence if liver function fails to recover.