Common polymorphisms in interleukin genes (IL4, IL6, IL8 and IL12) are not associated with alcoholic liver disease or alcoholism in Spanish men

IL-6 and IL-10 gene polymorphisms and cirrhosis of liver risk from a comprehensive analysis

BACKGROUND

Different inflammatory and immune cytokines play a key role in the development of cirrhosis of liver (CL). To investigate the association between interleukin-6,10 (IL-6,10) genes polymorphisms and CL risk through comparison of the allele and genotype distribution frequencies by meta-analysis.

METHODS

A literature search covered with the PubMed, Embase, Cochrane Library, Web of Science, Google Scholar, SinoMed (CNKI and Wanfang) through 20th April, 2021. Odds ratios (OR) and 95% confidence intervals (CI) were used to assess the strength of associations.

RESULTS

After a comprehensive search, three common polymorphisms (rs1800872, rs1800871, rs1800896) in IL-10 gene were selected, and three common polymorphisms (rs1800795, rs1800796, rs1800797) in IL-6 gene were also identified. The important finding was that IL-10 rs1800872 was a risk factor for CL development. For example, there has a significantly increased relationship between rs1800872 polymorphism and CL both in the whole group (OR: 1.30, 95%CI: 1.01-1.67 in heterozygote model), Asian population (OR: 1.40, 95%CI: 1.03-1.88 in heterozygote model) and hospital-based source of control (OR: 1.40, 95%CI: 1.01-1.96 in dominant model). In addition, significant association was found between rs1800896 and primary biliary cirrhosis subtype disease (OR: 1.30, 95%CI: 1.01-1.68 in allelic contrast model). No association was observed in all three polymorphisms in IL-6 gene.

CONCLUSION

Our present study suggests that the IL-10 rs1800872 and rs1800896 polymorphisms is potentially associated with the risk of CL susceptibility.

Interleukin-6 gene polymorphisms and susceptibility to liver diseases: A meta-analysis

BACKGROUND

Several studies have explored the associations between interleukin-6 (IL-6) gene polymorphisms and the susceptibility to liver diseases, however, results remain ambiguous. The goal of this study was to conduct a meta-analysis to provide more credible evidence.

METHODS

Studies identified in the PubMed, Cochrane Library, and EMBASE databases were used to perform a meta-analysis via the STATA software. Pooled odds ratios (OR) were calculated under fixed- and random-effects models to estimate the potential genetic associations.

RESULTS

Twenty-five case-control studies involving 5813 cases and 5298 controls were included in this meta-analysis. Overall, the pooled results suggested that rs1800795 polymorphism was significantly associated with the risk of liver diseases in heterozygote (GC vs CC; OR = 1.57) and dominant (GG+GC vs CC: OR = 1.47) models; rs1800796 polymorphism was significantly associated with the susceptibility to liver diseases in heterozygote (GG vs GC; OR = 0.58) and recessive (GG vs GC+CC: OR = 0.68) models; rs1800797 polymorphism was significantly associated with genetic predisposition to liver diseases in homozygote (GG vs AA: OR = 1.63), heterozygote (GA vs AA; OR = 1.53) and dominant (GG + GA vs AA: OR = 1.61) models. A similar conclusion was found in the HBV, HCV, HCC, NASH and alcoholic liver disease of all ethnic populations for rs1800795; HBV and Asian subgroups for rs1800796; HCV and non-Asian subgroups for rs1800797. However, IL-6 rs2069837 and rs2066992 polymorphisms did not exhibit significant associations with the risk of liver diseases under any genetic models.

CONCLUSION

This meta-analysis suggests that patients carrying G (rs1800795), C (rs1800796) or G (rs1800797) allele or genotypes of IL-6 may be more likely to suffer from liver diseases, which was ethnic-dependent.

Analysis of the relationship between interleukin polymorphisms within miRNA-binding regions and alcoholic liver disease

INTRODUCTION

Alcohol consumption promotes inflammation through the Toll-like receptor 4 (TLR4)/nuclear factor (NF)-?B pathway, leading to organic damage. Some micro-RNA (miRNA) molecules modulate this inflammatory response by downregulating TLR4/NF-?B pathway mediators, like interleukins (ILs). Thus, polymorphisms within IL genes located near miRNA binding sites could modify the risk of ethanol-induced damage. The present study analyzed potential relationships between alcoholism or alcoholic liver disease (ALD) and IL12B 2124 G>T (rs1368439), IL16 5000 C>T (rs1131445), IL1R1 3114 C>T (rs3917328), and NFKB1 3400 A>G (rs4648143) polymorphisms.

PATIENTS AND METHODS

The study included 301 male alcoholic patients and 156 male healthy volunteers. Polymorphisms were genotyped using TaqMan^® PCR assays for allelic discrimination. Allele and genotype frequencies were compared between groups. Logistic regression analysis was performed to analyze the inheritance model.

RESULTS

Analysis of the IL1R1 (rs3917328) polymorphism showed that the proportion of alleleT carriers (CT and TT genotypes) was higher in healthy controls (9.7%) than in alcoholic patients (6.5%; P=.042). However, multivariable logistic regression analyses did not yield a significant result. No differences between groups were found for other analyzed polymorphisms.

CONCLUSIONS

Our study describes, for the first time, the expected frequencies of certain polymorphisms within miRNA-binding sites in alcoholic patients with and without ALD. Further studies should be developed to clarify the potential relevance of these polymorphisms in alcoholism and ALD development.

New approaches for fibrosis regression in alcoholic cirrhosis

Liver fibrosis is a dynamic process of fibrinogenesis and fibrinolysis. It is sequelae of recurrent injury and inflammation to the liver. Only recently has there been significant progress in understanding the pathophysiology behind liver fibrosis. This has allowed for the development of identifiable targets for potential therapies. In this article we will discuss the underlying general cellular mechanisms that play a key role in the pathway of fibrinogenesis and fibrinolysis and then focus on the mechanisms that are key in alcohol-induced liver fibrosis. Challenges in formulating potential fibrosis therapies as well as current potential targets for liver fibrosis will be reviewed as well.

Alcoholic liver disease and hepatitis C virus infection

Alcohol consumption and hepatitis C virus (HCV) infection have a synergic hepatotoxic effect, and the coexistence of these factors increases the risk of advanced liver disease. The main mechanisms of this effect are increased viral replication and altered immune response, although genetic predisposition may also play an important role. Traditionally, HCV prevalence has been considered to be higher (up to 50%) in alcoholic patients than in the general population. However, the presence of advanced alcoholic liver disease (ALD) or intravenous drug use (IDU) may have confounded the results of previous studies, and the real prevalence of HCV infection in alcoholic patients without ALD or prior IDU has been shown to be lower. Due to the toxic combined effect of HCV and alcohol, patients with HCV infection should be screened for excessive ethanol intake. Patients starting treatment for HCV infection should be specifically advised to stop or reduce alcohol consumption because of its potential impact on treatment efficacy and adherence and may benefit from additional support during antiviral therapy. This recommendation might be extended to all currently recommended drugs for HCV treatment. Patients with alcohol dependence and HCV infection, can be treated with acamprosate, nalmefene, topiramate, and disulfiram, although baclofen is the only drug specifically tested for this purpose in patients with ALD and/or HCV infection.

Alcoholic liver disease and hepatitis C virus infection

Alcohol consumption and hepatitis C virus (HCV) infection have a synergic hepatotoxic effect, and the coexistence of these factors increases the risk of advanced liver disease. The main mechanisms of this effect are increased viral replication and altered immune response, although genetic predisposition may also play an important role. Traditionally, HCV prevalence has been considered to be higher (up to 50%) in alcoholic patients than in the general population. However, the presence of advanced alcoholic liver disease (ALD) or intravenous drug use (IDU) may have confounded the results of previous studies, and the real prevalence of HCV infection in alcoholic patients without ALD or prior IDU has been shown to be lower. Due to the toxic combined effect of HCV and alcohol, patients with HCV infection should be screened for excessive ethanol intake. Patients starting treatment for HCV infection should be specifically advised to stop or reduce alcohol consumption because of its potential impact on treatment efficacy and adherence and may benefit from additional support during antiviral therapy. This recommendation might be extended to all currently recommended drugs for HCV treatment. Patients with alcohol dependence and HCV infection, can be treated with acamprosate, nalmefene, topiramate, and disulfiram, although baclofen is the only drug specifically tested for this purpose in patients with ALD and/or HCV infection.

Association Between IL-4 Polymorphisms and Risk of Liver Disease: An Updated Meta-Analysis

Interleukin-4 (IL-4) polymorphisms have been reported to influence an individual's susceptibility to liver disease as it is a central anti-inflammatory Th2 cytokine; however, these results remain controversial.A comprehensive meta-analysis of the relevant literature was thus performed to better estimate the relationship between IL-4 polymorphisms and liver disease.Systematic searches of various databases (PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure) for studies published before July 5, 2015 were performed. Odds ratios (ORs) with 95% confidence intervals (CIs) calculated in fixed or random-effects models were used to estimate the strength of the association. Subgroup analyses, meta-regression, Galbraith plots, and sensitivity analyses were also performed.A total of 16 case-control studies, of which 15 involved the -590C/T polymorphism and 3 involved the -33T/C polymorphism, were included in the study. With respect to the -590C/T polymorphism, a significantly increased risk of liver diseases was found in the overall population (TT + CT vs CC: OR = 1.25, 95% CI = 1.06-1.49, P = 0.009 and CT vs CC: OR = 1.22, 95% CI = 1.00-1.48, P = 0.048) and the Asian population (TT + CT vs CC: OR = 1.28, 95% CI = 1.04-1.57, P = 0.020). Further subgroup analyses also showed significant associations between the -590C > T polymorphism and the risk of hepatitis C infection and hepatocellular carcinoma. However, no association was found between the -33T/C polymorphism and risk of liver diseases in all comparison models.This meta-analysis suggested that the IL-4 -590C > T polymorphism is associated with an increased risk of hepatitis C infection and hepatocellular carcinoma, especially among the Asian population.

Serum interleukin 8 and 12 levels predict severity and mortality in patients with alcoholic hepatitis

BACKGROUND

Alcoholic hepatitis (AH) is a common life-threatening illness particularly when it is severe. Alcoholic liver disease is associated with cytokine imbalance. There is paucity of information about the relationship of interleukin (IL) levels with severity and mortality of patients with AH. Our aim was to correlate serum IL-8 and IL-12 values with disease severity (mild vs. severe) and mortality.

METHODS

Fifty patients and 25 healthy subjects were included in the study. Serum IL-8 and -12 levels were analyzed and correlated with disease severity and mortality. Predictive value for 6 months mortality of IL-8, IL-12, Maddreys discriminant function (mDF), age, bilirubin, international normalized ratio, and creatinine score (ABIC) and Glasgow alcoholic hepatitis score (GAHS) was compared by the area under the receiver operating curve (AUROC).

RESULTS

Mean (±SD) serum IL-8 levels were significantly higher in patients with severe AH as compared to mild AH [539.04 ± 89.77 vs. 253.66 ± 56.66 pg/mL (p < 0.001)] and controls [539.04 ± 89.77 vs. 99.96 ± 20.94 pg/mL (p < 0.001)]. Similarly, mean (+SD) serum IL-12 levels in severe AH were also significantly higher as compared to mild AH [344.47 ± 93.04 vs. 101.92 ± 16.70 pg/mL (p < 0.001)] and controls [344.47 ± 93.04 vs. 47.84 ± 11.22 pg/mL (p < 0.001)]. AUROCs of IL-8, IL-12, mDF, ABIC, and GAHS were 0.995, 0.998, 0.975, 0.873, and 0.883 for predicting 6 months mortality.

CONCLUSION

Serum IL-8 and -12 levels were markedly elevated in AH with increasing levels as the severity increases. Serum levels of IL-8 and -12 were better predictors of short-term mortality as compared to conventional prognostic scores.

Alcohol dehydrogenase-specific T-cell responses are associated with alcohol consumption in patients with alcohol-related cirrhosis

Patients with alcohol-related liver disease (ALD) have antibodies directed to alcohol dehydrogenase (ADH), anti-ADH titers being associated with disease severity and active alcohol consumption. ADH-specific T-cell responses have not been characterized. We aimed to define anti-ADH cellular immune responses and their association with active alcohol consumption and disease severity. Using cultures of peripheral blood mononuclear cells (PBMCs) from 25 patients with alcohol-related cirrhosis (ARC; 12 were actively drinking or abstinent for <6 months, and 13 were abstinent for >6 months) and hepatic mononuclear cells (HMCs) from 14 patients with ARC who were undergoing transplantation, we investigated T-cell reactivity to 25 overlapping peptides representing the full human ADH protein (beta 1 subunit). ADH-specific peripheral T-cell responses were assessed by the quantification of T-cell proliferation and cytokine production and were correlated with the clinical course. In active alcohol consumers, proliferative T-cell responses targeted ADH31-95 and other discontinuous sequences in the ADH peptide, whereas only one sequence was targeted in abstinents. ADH peptides induced the production of interferon-γ (IFN-γ), interleukin-4 (IL-4), and IL-17. IL-4 production was lower in active drinkers versus abstinents, and IL-17 production was higher. Peptides inducing IFN-γ production outnumbered those inducing T-cell proliferation. The intensity of the predominantly T helper 1 (Th 1) responses directly correlated with disease severity. Similar to PBMCs in abstinents, ADH peptides induced weak T-cell proliferation and a similar level of IL-4 production in HMCs but less vigorous Th 1 and T helper 17 responses.

CONCLUSION

This suggests that Th 1 responses to ADH in ARC are induced by alcohol consumption. A Th 1/T helper 2 imbalance characterizes T-cell responses in active drinkers with ARC, whereas IL-4 production prevails in abstinents. This identifies new targets for immunoregulatory therapies in ALD patients for halting detrimental effector T-cell responses, which may encourage liver fibrogenesis and progression to end-stage liver disease.

Genetic association of interleukin-6 polymorphism (-174 G/C) with chronic liver diseases and hepatocellular carcinoma

Interleukin-6 (IL-6) is a pleiotropic cytokine which is expressed in many inflammatory cells in response to different types of stimuli, regulating a number of biological processes. The IL-6 gene is polymorphic in both the 5’ and 3’ flanking regions and more than 150 single nucleotide polymorphisms have been identified so far. Genetic polymorphisms of IL-6 may affect the outcomes of several diseases, where the presence of high levels of circulating IL-6 have been correlated to the stage and/or the progression of the disease itself. The -174 G/C polymorphism is a frequent polymorphism, that is located in the upstream regulatory region of the IL-6 gene and affects IL-6 production. However, the data in the literature on the genetic association between the -174 G/C polymorphism and some specific liver diseases characterized by different etiologies are still controversial. In particular, most of the studies are quite unanimous in describing a correlation between the presence of the high-producer genotype and a worse evolution of the chronic liver disease. This is valid for patients with hepatitis C virus (HCV)-related chronic hepatitis and liver cirrhosis and hepatocellular carcinoma (HCC) whatever the etiology. Studies in hepatitis B virus-related chronic liver diseases are not conclusive, while specific populations like non alcoholic fatty liver disease/non-alcoholic steatohepatitis, autoimmune and human immunodeficiency virus/HCV co-infected patients show a higher prevalence of the low-producer genotype, probably due to the complexity of these clinical pictures. In this direction, a systematic revision of these data should shed more light on the role of this polymorphism in chronic liver diseases and HCC.

Implications of central immune signaling caused by drugs of abuse: mechanisms, mediators and new therapeutic approaches for prediction and treatment of drug dependence

In the past two decades a trickle of manuscripts examining the non-neuronal central nervous system immune consequences of the drugs of abuse has now swollen to a significant body of work. Initially, these studies reported associative evidence of central nervous system proinflammation resulting from exposure to the drugs of abuse demonstrating key implications for neurotoxicity and disease progression associated with, for example, HIV infection. However, more recently this drug-induced activation of central immune signaling is now understood to contribute substantially to the pharmacodynamic actions of the drugs of abuse, by enhancing the engagement of classical mesolimbic dopamine reward pathways and withdrawal centers. This review will highlight the key in vivo animal, human, biological and molecular evidence of these central immune signaling actions of opioids, alcohol, cocaine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA). Excitingly, this new appreciation of central immune signaling activity of drugs of abuse provides novel therapeutic interventions and opportunities to identify 'at risk' individuals through the use of immunogenetics. Discussion will also cover the evidence of modulation of this signaling by existing clinical and pre-clinical drug candidates, and novel pharmacological targets. Finally, following examination of the breadth of central immune signaling actions of the drugs of abuse highlighted here, the current known common immune signaling components will be outlined and their impact on established addiction neurocircuitry discussed, thereby synthesizing a common neuroimmune hypothesis of addiction.

Association of IL-1B genetic polymorphisms with an increased risk of opioid and alcohol dependence

OBJECTIVE

To examine the association between genetic variability of IL-1B, which encodes for the proinflammatory cytokine IL-1beta and the risk of developing opioid dependence. To confirm a previous study, we also examined the association between the IL-1B genetic polymorphism and alcohol dependence.

METHODS

Genomic DNA was isolated from 60 opioid-dependent, 99 alcohol-dependent patients and 60 healthy nondependent controls. Polymerase chain reaction and restriction fragment length polymorphism were used to determine the presence of single nucleotide polymorphisms at positions -511, -31 and 3954 of IL-1B.

RESULTS

IL-1B -511C and -31T alleles were more frequent in both the opioid-dependent and alcohol-dependent patients compared with the control group: odds ratio (OR, 95% confidence interval) P values corrected for false discovery rate=1.91 (1.14-3.20), P=0.043 and 1.89 (1.19-2.99), P=0.014, respectively, for IL-1B -511C>T; and OR=1.74 (1.02-2.97), P=0.066 and 1.80 (1.13-2.88), P=0.017, respectively, for IL-1B -31T>C. In contrast, no association was observed between opioid dependence and the IL-1B 3954C>T single nucleotide polymorphism [OR=1.60 (0.84-3.02), P=0.15].

CONCLUSION

This study confirms the previous finding that IL-1B polymorphism is associated with altered risk of alcohol dependence. IL-1B single nucleotide polymorphisms at position -511 and -31, which increase IL-1beta production, occur at a higher frequency in opioid-dependent populations and may be associated, albeit weakly, with an increased risk of opioid dependence.

Paget's disease of bone is not associated with common polymorphisms in interleukin-6, interleukin-8 and tumor necrosis factor alpha genes

BACKGROUND

Cytokines, specially interleukin (IL)-6, play an important role in the differentiation and activation of osteoclasts and might be involved in osteoblast stimulation in Paget's disease of bone (PDB).

OBJECTIVES

The aim of this study was to investigate the association of polymorphisms in IL-6, IL-8 and tumor necrosis factors-alpha (TNFA) genes among Spanish patients with PDB.

METHODS

We studied four single nucleotide polymorphisms (-174 G>C IL-6, -251 T>A IL-8, -238 G>A TNFA and -308 G>A TNFA) in 172 PDB patients and 150 healthy controls. Distribution of alleles and pro-inflammatory genotypes were studied for association with the presence of the disease and with clinical and laboratory data, as well as the response to bisphosphonate treatment in PDB patients.

RESULTS

We found no statistically significant association between genotype and allele distribution of any of the cytokines polymorphism studied and PDB. No association between the clinical and therapeutic characteristics of PDB and the investigated polymorphism were found.

CONCLUSIONS

This study does not support the hypothesis that the analyzed IL6, IL8 and TNFA polymorphism are associated with PDB.

A functional polymorphism of the NFKB1 gene increases the risk for alcoholic liver cirrhosis in patients with alcohol dependence

BACKGROUND

The genetic basis for the predisposition to alcoholic liver cirrhosis (ALC) remains unknown. Increasing evidence supports a role for the nuclear factor (NF)-kappaB, the NF-kappaB inhibitor alpha (NFKBIA), and the peroxisome proliferator-activated receptor (PPAR)-gamma in the pathogenesis of alcoholic liver disease, raising the possibility that common polymorphisms in genes encoding these molecules may confer susceptibility to ALC. The objective of this study was to analyze the relationship between common polymorphisms in NFKB1, NFKBIA, and PPARG2 genes and the presence of ALC.

METHODS

A total of 258 male alcoholics (161 without liver disease and 97 with ALC) and 101 healthy controls were genotyped for the -94ins/delATTG NFKB1, 3'-UTR+126G>A NFKBIA, and 34C>G PPARG2 polymorphisms. The association of these genetic variants with ALC was tested in alcoholic patients with alcohol abuse and alcohol dependence. A logistic regression analysis was further performed to analyze the model of inheritance.

RESULTS

We found an association between the presence of the deletion allele in NFKB1 polymorphism and ALC in patients with alcohol dependence. We found no association between NFKBIA and PPARG2 polymorphisms and the presence of ALC.

CONCLUSIONS

The deletion allele of the -94ins/del NFKB1 polymorphism could be associated with a higher risk of developing ALC through an increase in inflammation, as supported by previous data.