Alcohol affects the late differentiation of progenitor B cells

Pathogenesis of Alcohol-Associated Liver Disease

Excessive alcohol consumption is a global healthcare problem with enormous social, economic, and clinical consequences. While chronic, heavy alcohol consumption causes structural damage and/or disrupts normal organ function in virtually every tissue of the body, the liver sustains the greatest damage. This is primarily because the liver is the first to see alcohol absorbed from the gastrointestinal tract via the portal circulation and second, because the liver is the principal site of ethanol metabolism. Alcohol-induced damage remains one of the most prevalent disorders of the liver and a leading cause of death or transplantation from liver disease. Despite extensive research on the pathophysiology of this disease, there are still no targeted therapies available. Given the multifactorial mechanisms for alcohol-associated liver disease pathogenesis, it is conceivable that a multitherapeutic regimen is needed to treat different stages in the spectrum of this disease.

Alcoholic liver disease: Current insights into cellular mechanisms

Alcoholic liver disease (ALD) due to chronic alcohol consumption is a significant global disease burden and a leading cause of mortality. Alcohol abuse induces a myriad of aberrant changes in hepatocytes at both the cellular and molecular level. Although the disease spectrum of ALD is widely recognized, the precise triggers for disease progression are still to be fully elucidated. Oxidative stress, mitochondrial dysfunction, gut dysbiosis and altered immune system response plays an important role in disease pathogenesis, triggering the activation of inflammatory pathways and apoptosis. Despite many recent clinical studies treatment options for ALD are limited, especially at the alcoholic hepatitis stage. We have therefore reviewed some of the key pathways involved in the pathogenesis of ALD and highlighted current trials for treating patients.

Alcoholism and Osteoimmunology

BACKGROUND

Chronic consumption of alcohol has an adverse effect on the skeletal system, which may lead to osteoporosis, delayed fracture healing and osteonecrosis of the femoral head. Currently, the treatment is limited, therefore, there is an urgent need to determine the underline mechanism and develop a new treatment. It is well-known that normal bone remodeling relies on the balance between osteoclast-mediated bone resorption and - mediated bone formation. Various factors can destroy the balance, including the dysfunction of the immune system. In this review, we summarized the relevant research in the alcoholic osteopenia with a focus on the abnormal osteoimmunology signals. We provided a new theoretical basis for the prevention and treatment of the alcoholic bone.

METHODS

We searched PubMed for publications from 1 January 1980 to 1 February 2020 to identify relevant and recent literature, summarizing evaluation and the prospect of alcoholic osteopenia. Detailed search terms were 'alcohol', 'alcoholic osteoporosis', 'alcoholic osteopenia' 'immune', 'osteoimmunology', 'bone remodeling', 'osteoporosis treatment' and 'osteoporosis therapy'.

RESULTS

A total of 135 papers are included in the review. About 60 papers described the mechanisms of alcohol involved in bone remodeling. Some papers were focused on the pathogenesis of alcohol on bone through osteoimmune mechanisms.

CONCLUSION

There is a complex network of signals between alcohol and bone remodeling and intercellular communication of osteoimmune may be a potential mechanism for alcoholic bone. Studying the osteoimmune mechanism is critical for drug development specific to the alcoholic bone disorder.

Recent Insights Into the Role of Immune Cells in Alcoholic Liver Disease

Accumulating clinical and experimental evidences have demonstrated that both innate and adaptive immunity are involved in the pathogenesis of alcoholic liver disease (ALD), in which the role of immunity is to fuel the inflammation and to drive the progression of ALD. Various immune cells are implicated in the pathogenesis of ALD. The activation of innate immune cells induced by alcohol and adaptive immune response triggered by oxidative modification of hepatic constituents facilitate the persistent hepatic inflammation. Meanwhile, the suppressed antigen-presenting capability of various innate immune cells and impaired function of T cells may consequently lead to an increased risk of infection in the patients with advanced ALD. In this review, we summarized the significant recent findings of immune cells participating in ALD. The pathways and molecules involved in the regulation of specific immune cells, and novel mediators protecting the liver from alcoholic injury via affecting these cells are particularly highlighted. This review aims to update the knowledge about immunity in the pathogenesis of ALD, which may facilitate to enhancement of currently available interventions for ALD treatment.

Hepatic Immune Microenvironment in Alcoholic and Nonalcoholic Liver Disease

Many types of innate (natural killer cells, natural killer T cells, and Kupffer cells/macrophages) and adaptive (T cells and B cells) immune cells are enriched within the liver and function in liver physiology and pathology. Liver pathology is generally induced by two types of immunologic insults: failure to eliminate antigens derived from the gastrointestinal tract which are important for host defense and an impaired tissue protective tolerance mechanism that helps reduce the negative outcomes of immunopathology. Accumulating evidence from the last several decades suggests that hepatic immune cells play an important role in the pathogenesis of alcoholic and nonalcoholic liver injury and inflammation in humans and mice. Here, we focus on the roles of innate and adaptive immune cells in the development and maintenance of alcoholic liver disease and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Additionally, the pathogenesis of liver disease and new therapeutic targets for preventing and treating alcoholic liver disease and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis are discussed.

Alcohol and tobacco consumption affect the oral carriage of Candida albicans and mutans streptococci

This study sought to determine if there is a relationship between the consumption of alcohol and tobacco and oral colonization by mutans streptococci and Candida species. Subjects were recruited from the University Dental Clinic of CEU Cardenal Herrera University (Moncada, Valencia). Information on alcohol and tobacco consumption was obtained by questionnaire. Individual stimulated saliva samples from 105 patients were obtained and selective media was used to isolate and quantify mutans streptococci and Candida spp. colony forming units per millilitre of saliva (CFU ml(-1) ). Samples were stratified by duration and quantity of alcohol and tobacco consumption. Alcohol consumption statistically significantly decreased oral carriage of mutans streptococci, whereas there was no effect on Candida albicans colonization levels. Tobacco users were found to harbour elevated levels of C. albicans; however, there was no observed effect on bacterial colonization by mutans streptococci. The carriage of other species investigated, such as Candida krusei, Candida tropicalis and lactobacilli, do not show a response to the consumption of the stimulants analysed. Microbial colonization of the oral cavity changes in a species-specific manner in response to dietary and social habits such as drinking alcohol and smoking.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this paper, we evaluate the effect of alcohol and tobacco consumption on key species of the oral microflora. Our results show species-specific changes in two major opportunistic pathogens, such as Candida albicans and mutans streptococci, whereas other members of oral microflora are not affected by the consumption of the stimulants studied. We believe this original paper will contribute to raise awareness among the dental community towards a more personalized oral health assessment, taking in consideration alcohol and tobacco consumption in the prevention of specific oral and systemic pathologies.

Re-examination of Opisthorchis viverrini Infection in Northeast Thailand

BACKGROUND

Liver fluke infection caused by the parasite Opisthorchis viverrini (O. viverrini), a human carcinogen, is endemic in north-eastern Thailand and remains a major health problem.

OBJECTIVES

The objectives of the study were to (1) resurvey the prevalence of O. viverrini infection in a field site from the Khon Kaen Cohort Study (in newly recruited subjects as well as previous cohort subjects surveyed in 1992); (2) investigate how subjects' lifestyle habits and their exposure to health promotion initiatives influence changes in prevalence of O. viverrini infection.

MATERIALS AND METHODS

The prevalence of O. viverrini infection in the cohort subjects (as well as new subjects) was investigated using faecal egg counts. Information on demographic factors, lifestyle and awareness of health promotion initiatives were obtained through questionnaires.

RESULTS

O. viverrini infection rates in the same individuals of the cohort were lower in 2006 than in 1992. Also, by studying the period effect, the current 35-44 year olds had a 12.4% (95% CI 3.9% to 20.9%) lower prevalence of O. viverrini infection than the 35-44 year olds in 1992 (24.2% versus 11.8%). Lifestyle choices showed that smoking and alcohol consumption were associated with an increased chance of acquiring O. viverrini infection with adjusted odds ratios of 10.1 (95%CI 2.4-41.6) and 5.3 (95%CI 1.2-23.0), respectively.

CONCLUSIONS

Our study has demonstrated that although the prevalence of O. viverrini infection over a 14-year period has decreased, unhealthy lifestyle was common with smoking and alcohol consumption being associated with increased chances of infection, emphasising the double burden of disease which developing countries are facing.

Altered Distribution of Peripheral Blood Maturation-Associated B-Cell Subsets in Chronic Alcoholism

BACKGROUND

Although decreased counts of peripheral blood (PB) B cells-associated with an apparently contradictory polyclonal hypergammaglobulinemia-have been reported in chronic alcoholism, no information exists about the specific subsets of circulating B cells altered and their relationship with antibody production. Here, we analyzed for the first time the distribution of multiple maturation-associated subpopulations of PB B cells in alcoholism and its potential relationship with the onset of liver disease.

METHODS

PB samples from 35 male patients-20 had alcoholic hepatitis (AH) and 15 chronic alcoholism without liver disease (AWLD)-were studied, in parallel to 19 male healthy donors (controls). The distribution of PB B-cell subsets (immature/regulatory, naïve, CD27(-) and CD27(+) memory B lymphocytes, and circulating plasmablasts of distinct immunoglobulin-Ig-isotypes) was analyzed by flow cytometry.

RESULTS

Patients with AH showed significantly decreased numbers of total PB B lymphocytes (vs. controls and AWLD), at the expense of immature, memory, and, to a lesser extent, also naïve B cells. AWLD showed reduced numbers of immature and naïve B cells (vs. controls), but higher PB counts of plasmablasts (vs. the other 2 groups). Although PB memory B cells were reduced among the patients, the percentage of surface (s)IgA(+) cells (particularly CD27(-) /sIgA(+) cells) was increased in AH, whereas both sIgG(+) and sIgA(+) memory B cells were significantly overrepresented in AWLD versus healthy donors. Regarding circulating plasmablasts, patients with AH only showed significantly reduced counts of sIgG(+) cells versus controls. In contrast, the proportion of both sIgA(+) and sIgG(+) plasmablasts-from all plasmablasts-was reduced in AH and increased in AWLD (vs. the other 2 groups).

CONCLUSIONS

AH and AWLD patients display a significantly reduced PB B-cell count, at the expense of decreased numbers of recently produced immature/regulatory B cells and naïve B cells, together with an increase in Ig-switched memory B lymphocytes and plasmablasts, particularly of IgA(+) cells.

Impact of Alcohol Abuse on the Adaptive Immune System

Alcohol exposure, and particularly chronic heavy drinking, affects all components of the adaptive immune system. Studies both in humans and in animal models determined that chronic alcohol abuse reduces the number of peripheral T cells, disrupts the balance between different T-cell types, influences T-cell activation, impairs T-cell functioning, and promotes T-cell apoptosis. Chronic alcohol exposure also seems to cause loss of peripheral B cells, while simultaneously inducing increased production of immunoglobulins. In particular, the levels of antibodies against liver-specific autoantigens are increased in patients with alcoholic liver disease and may promote alcohol-related liver damage. Finally, chronic alcohol exposure in utero interferes with normal T-cell and B-cell development, which may increase the risk of infections during both childhood and adulthood. Alcohol's impact on T cells and B cells increases the risk of infections (e.g., pneumonia, HIV infection, hepatitis C virus infection, and tuberculosis), impairs responses to vaccinations against such infections, exacerbates cancer risk, and interferes with delayed-type hypersensitivity. In contrast to these deleterious effects of heavy alcohol exposure, moderate alcohol consumption may have beneficial effects on the adaptive immune system, including improved responses to vaccination and infection. The molecular mechanisms underlying ethanol's impact on the adaptive immune system remain poorly understood.

Alcoholism: A systemic proinflammatory condition

Excessive ethanol consumption affects virtually any organ, both by indirect and direct mechanisms. Considerable research in the last two decades has widened the knowledge about the paramount importance of proinflammatory cytokines and oxidative damage in the pathogenesis of many of the systemic manifestations of alcoholism. These cytokines derive primarily from activated Kupffer cells exposed to Gram-negative intestinal bacteria, which reach the liver in supra-physiological amounts due to ethanol-mediated increased gut permeability. Reactive oxygen species (ROS) that enhance the inflammatory response are generated both by activation of Kupffer cells and by the direct metabolic effects of ethanol. The effects of this increased cytokine secretion and ROS generation lie far beyond liver damage. In addition to the classic consequences of endotoxemia associated with liver cirrhosis that were described several decades ago, important research in the last ten years has shown that cytokines may also induce damage in remote organs such as brain, bone, muscle, heart, lung, gonads, peripheral nerve, and pancreas. These effects are even seen in alcoholics without significant liver disease. Therefore, alcoholism can be viewed as an inflammatory condition, a concept which opens the possibility of using new therapeutic weapons to treat some of the complications of this devastating and frequent disease. In this review we examine some of the most outstanding consequences of the altered cytokine regulation that occurs in alcoholics in organs other than the liver.

The influential roles of antibiotics prophylaxis in cirrhotic patients with peptic ulcer bleeding after initial endoscopic treatments

The influential roles of antibiotic prophylaxis on cirrhotic patients with peptic ulcer bleeding are still not well documented. The purpose of this study is to clarify these influential roles and to identify the risk factors associated with rebleeding, bacterial infection and in-hospital mortality. A cross-sectional, chart review study was conducted on 210 cirrhotic patients with acute peptic ulcer hemorrhage who underwent therapeutic endoscopic procedures. Patients were divided into group A (with prophylactic intravenous ceftriaxone, n = 74) and group B (without antibiotics, n = 136). The outcomes were length of hospital days, prevention of infection, rebleeding rate and in-hospital mortality. Our results showed that more patients suffered from rebleeding and infection in group B than group A (31.6% vs. 5.4%; p<0.001 and 25% vs. 10.8%; p = 0.014 respectively). The risk factors for rebleeding were active alcoholism, unit of blood transfusion, Rockall score, model for end-stage liver disease score and antibiotic prophylaxis. The risk factors for infection were active alcoholism, Child-Pugh C, Rockall score and antibiotic prophylaxis. Rockall score was the predictive factor for in-hospital mortality. In conclusions, antibiotic prophylaxis in cirrhotic patients after endoscopic interventions for acute peptic ulcer hemorrhage reduced infections and rebleeding rate but not in-hospital mortality. Rockall score was the predictive factor of in-hospital mortality.

Influence of experimental alcohol administration on serum immunoglobulin levels: contrasting effects on IgE and other immunoglobulin classes

In humans, alcoholic liver disease is associated with hypergammaglobulinemia, particularly with high serum concentrations of IgA. Furthermore, alcohol consumption is associated with high concentrations of IgE and low concentrations of IgG. However, there is little experimental evidence to corroborate these observational findings. The objective of the present study was to investigate the potential short-term effects of alcohol administration on serum immunoglobulin concentrations in mice, and the potential influence of sex and strain on these effects. Eight mouse groups were defined by strain (Swiss vs C57BL/6), sex (male vs female), and experimental procedure (alcohol administration vs control diet). Alcohol was administered in a semi-liquid diet (6.5%v/v); control animals received an isocaloric semi-liquid diet. Immunoglobulin concentrations (IgE, IgA, IgM, IgG1, IgG2a, IgG2b, and IgG3) were measured at baseline and weekly thereafter for 4 weeks. Serum Th1 (interferon-gamma) and Th2 (IL-4 and IL-13) cytokines were measured at week 4. We found significant variations in baseline immunoglobulin concentrations depending upon mouse sex and strain. Alcohol administration was quickly followed by an increase in serum IgE concentrations in all experimental groups. IgE increase was correlated with serum IL-13 increase. In contrast, alcohol administration was not associated with significant changes in serum IgA and IgM concentration, and appeared to decrease IgG subclass concentrations. Alcohol effects on immunoglobulin concentrations were independent of mouse strain and sex. In conclusion, alcohol administration in mice had contrasting effects on IgE and other immunoglobulin classes. This experimental evidence confirms observational results in humans.