Gut-liver axis: an immune link between celiac disease and primary biliary cirrhosis

Gastrointestinal and Hepatobiliary Manifestations Associated with Untreated Celiac Disease in Adults and Children: A Narrative Overview

Celiac disease (CeD) is a chronic inflammatory disease of the small intestine, produced by ingesting dietary gluten products in susceptible people. Gluten causes an impairment of the mucosal surface and, consequently, an abnormal absorption of nutrients. Although malabsorption of essential nutrients is a major risk factor for various CeD-associated morbidities, genetic, immunological, and environmental factors also play an important role. The clinical presentation of CeD widely varies and can range from asymptomatic to full-blown symptoms due to the multi-system nature of CeD. The typical gastrointestinal (GI) manifestations of CeD include abdominal pain, diarrhea, bloating, and weight loss, but several hepatobiliary manifestations and a poor nutritional status have also been described. Currently, a gluten-free diet (GFD) is the only current evidence-based treatment that leads to the complete recovery of mucosal damage and the reversibility of its progression. Conversely, undiagnosed CeD might have severe consequences in children as well as in adult patients. This narrative overview aims to characterize the GI and hepatobiliary manifestations, nutritional deficiencies, and delayed pediatric development associated with unrecognized CeD in order to identify it promptly. Moreover, the role of GFD and how it could prevent long-term complications of CeD are described.

Dissecting causal relationships between primary biliary cholangitis and extrahepatic autoimmune diseases based on Mendelian randomization

As an autoimmune disease, up to 73% of patients with primary biliary cholangitis (PBC) have a combination of extrahepatic autoimmune diseases (EHAIDs); however, the causal relationship between PBC and EHAIDs is unclear. The genome-wide association analyses provided 14 GWAS data for PBC and EHAIDs, and bidirectional, two-sample MR analyses were performed to examine the relationship between PBC and EHAIDs. The analysis using MR provides a strong and meaningful estimation of the bidirectional correlation between PBC and 7 EHAIDs: rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, autoimmune hypothyroidism, inflammatory bowel disease and ulcerative colitis of its types. In addition, PBC increases the risk of autoimmune thyroid diseases such as autoimmune hyperthyroidism and Graves' disease, as well as multiple sclerosis and psoriasis. Additionally, PBC is identified as a risk factor for Crohn's disease and Celiac disease. Based on genetic evidence, there may be connections between PBC and specific EHAIDs: not all coexisting EHAIDs induce PBC, and vice versa. This underscores the significance of prioritizing PBC in clinical practice. Additionally, if any liver function abnormalities are observed during treatment or with EHAIDs, it is crucial to consider the possibility of comorbid PBC.

Gluten and Wheat in Women's Health: Beyond the Gut

Since the rise of awareness of gluten/wheat-related disorders in the academic and clinical field in the last few decades, misinformation regarding the gluten-free diet (GFD) and its impact on health has been spreading among the general population. Despite the established link between gluten and celiac disease (CD), where a GFD is mandatory to reach clinical and histological remission, things are more complicated when it comes to non-celiac gluten/wheat sensitivity (NCGWS) and other autoimmune/dysimmune disorders. In the last conditions, a beneficial effect of gluten withdrawal has not been properly assessed, but still is often suggested without strong supporting evidence. In this context, women have always been exposed, more than men, to higher social pressure related to nutritional behaviors and greater engagement in controlling body weight. With this narrative review, we aim to summarize current evidence on the adherence to a GFD, with particular attention to the impact on women's health.

Extra-intestinal manifestations of Celiac disease in children: their prevalence and association with human leukocyte antigens and pathological and laboratory evaluations

BACKGROUND

Celiac disease (CD) is an autoimmune disease caused by gluten intake. Traditionally CD was believed to be a disease of the gut, although a wide range of extra-intestinal manifestations (EIM) was recognized. The exact prevalence of EIM and the associated risk factors have not been well studied.

AIM

We aimed to assess the prevalence of EIM in children with CD and their association with human leukocyte antigen (HLA) typing, and pathological and laboratory indices.

METHOD

We conducted a cross-sectional study on children and adolescents with a definite diagnosis of CD. They were followed in the main Celiac Clinic of Southern Iran.

RESULTS

We included 204 children who were visited between 2012 and 2017. Nearly 85% of them were positive for HLA-DQ2 and 40.6% for HLA-DQ8. The most prevalent intestinal complaints reported were abdominal pain (42.6%) and chronic constipation (19.1%). Failure-to-thrive (32.7%), iron deficiency anemia (25%), short stature (20.5%), and eczema (18.6%) were the most common EIMs. However, failure-to-thrive and short stature were presented at significantly younger ages, whereas those patients with concomitant type 1 diabetes mellitus (DM) were significantly older. We also found significant relationships between autoimmune thyroid disease and HLA-DQ5, and the presence of headaches with HLA-DQ7. The prevalence of HLA types of DQ2, DQ8, DQ6, and DQ7 significantly varied among different Marsh groups. Patients who were positive for HLA-DQ8, were significantly older, taller, and weightier. No significant association was found between HLA types and any of the gastrointestinal symptoms, anti-tTG and compliance to gluten free diet. Moreover, there were no statistically significant differences detected between the presence of each individual EIM, the level of IgA anti-tTG, sex, and Marsh typing.

CONCLUSION

This study highlights the presence of EIM in CD and their associated factors. We show the potential role of HLA typing in some EIMs, which may shed light for future studies.

Life-threatening onset of coeliac disease: a case report and literature review

BACKGROUND

Coeliac disease (CD) results from an immune-mediated reaction to gluten in genetically predisposed individuals. In rare cases CD may occur with acute features deferring the diagnosis and exposing these patients to possible life-threatening complications. Herein we present the case of a young woman with a coeliac crisis, that is, a sudden clinical onset characterised by severe electrolyte imbalance due to an unknown (previously unrecognised) CD.

METHODS

This is a case report and literature review revealing that coeliac crisis is under-reported, with a total of 48 adult cases so far published. The diagnosis in our case was established by histopathological analysis of multiple duodenal biopsies. The patient's serum was tested by enzyme-linked immunoassay to detect antitransglutaminase IgA antibodies.

RESULTS

In contrast to cases reported in the literature, with male gender predominance and a mean age of 50±17 years, our patient was a young female case of coeliac crisis. However, like in our patient, a higher incidence of coeliac crisis was associated with the human leucocyte antigen (HLA)-DQ2 haplotype, versus HLA-DQ8, and a severe (Marsh-Oberhüber 3c) duodenal mucosa atrophy. Notably, there is no clear correlation between the antitissue transglutaminase 2 IgA antibody titre and coeliac crisis onset/severity, as confirmed by our case report.

CONCLUSIONS

The present case highlights that CD may manifest quite abruptly with a severe malabsorption syndrome, that is, electrolyte abnormalities and hypoproteinaemia. Our case should alert physicians, in particular those in the emergency setting, that even a typically chronic disorder, such as CD, may show life-threatening complications requiring urgent management.

Effect of Gluten-Free Diet on Gut Microbiota Composition in Patients with Celiac Disease and Non-Celiac Gluten/Wheat Sensitivity

Celiac disease (CD) and non-celiac gluten/wheat sensitivity (NCG/WS) are the two most frequent conditions belonging to gluten-related disorders (GRDs). Both these diseases are triggered and worsened by gluten proteins ingestion, although other components, such as amylase/trypsin inhibitors (ATI) and fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), seem to be involved in the NCG/WS onset. Therefore, the only effective treatment to date is the long-life adherence to a strictly gluten-free diet. Recently, increasing attention has been paid to the intestinal barrier, a dynamic system comprising various components, which regulate the delicate crosstalk between metabolic, motor, neuroendocrine and immunological functions. Among the elements characterizing the intestinal barrier, the microbiota plays a key role, modulating the gut integrity maintenance, the immune response and the inflammation process, linked to the CD and NCG/WS outbreak. This narrative review addresses the most recent findings on the gut microbiota modulation induced by the gluten-free diet (GFD) in healthy, CD and NCG/WS patients.

Prevalence of Celiac Disease in Patients with Primary Biliary Cholangitis

Background

Primary biliary cholangitis (PBC) frequently coexists with other autoimmune diseases, including celiac disease (CeD). Although the prevalence of CeD is high among cohorts with PBC, few studies have directly compared this prevalence to those among individuals with other liver diseases (OLD).

Aim

To compare the prevalence of CeD between a cohort with PBC and a cohort with OLD.

Methods

Retrospective study from January 2013 to December 2016. All consecutive patients with an anti-transglutaminase (tTG) assay requested by a hepatologist and a diagnosis of chronic liver disease were included. CeD diagnosis was confirmed by duodenal biopsies.

Results

We included 399 consecutive patients (53.1 years SD 14.0, 54.1% women), notably 51 individuals with PBC and 348 individuals with OLD. PBC group included significantly more women (90.2% versus 48.9% P < 0.0001). The prevalence of CeD was higher in the group with PBC compared to the group with OLD (11.8 versus 2.9%, P < 0.003). In the OLD group, the prevalence of CeD was comparable regardless of the etiologic subgroup (nonalcoholic steatohepatitis 2.7% versus alcoholic liver disease 4.3%, versus viral 1.5% versus other autoimmune liver diseases 3.3%, NS). The presence of gastrointestinal symptoms at the time of the tTG assay was comparable between PBC and OLD groups (31.4 versus 29.6%, NS).

Conclusion

There is a higher prevalence of CeD in the PBC group compared to other liver diseases.

Celiac Disease: Extraintestinal Manifestations and Associated Conditions

Celiac disease is a common form of enteropathy with frequent extraintestinal manifestations (EIM). Misrecognition of these presentations may lead to significant delays in diagnosis. Any organ may be involved, either through an immune/inflammatory phenomenon, or nutritional deficiencies. Some EIM, such as gluten ataxia, may be irreversible if left untreated, but most will improve with a gluten-free diet. Knowledge of the various EIM, as well as the associated conditions which do not improve on a gluten-free diet, will avoid delays in the diagnosis and management of celiac disease and associated manifestations.

Incidence, prevalence, and outcome of primary biliary cholangitis in a nationwide Swedish population-based cohort

Available epidemiological data on primary biliary cholangitis (PBC) in Sweden originate from regional studies in the 1980s and may not reflect modern day PBC. We aimed to estimate incidence and prevalence, survival and death causes, and gender differences in PBC. We used international classification of disease (ICD) codes to identify patients with PBC in inpatient and outpatient registries 1987-2014 who were then linked to the Swedish cause of death, cancer and prescribed drug registries. Each PBC patient was matched with 10 reference individuals from the general population. In sensitivity analyses, we examined PBC patients identified through clinical patient records from Karolinska, Sahlgrenska and Örebro University Hospitals. We identified 5,350 adults with PBC. Prevalence of PBC increased steadily from 5.0 (1987) to 34.6 (2014) per 100,000 inhabitants whereas the yearly incidence rate was relatively constant with a median of 2.6 per 100,000 person-years, with a female:male gender ratio of 4:1. Compared to reference individuals, PBC individuals aged 15-39 years at diagnosis had a substantially higher risk of death (Hazard Ratio [HR] 12.7, 95% Confidence Interval [CI] 8.3-19.5) than those diagnosed between 40-59 (HR 4.1, 95% CI 3.7-4.5) and >60 (HR 3.7, 95% CI 3.5-3.9) years of age. Relative risks of mortality were highest in men. In conclusion, we found that recorded prevalence of PBC in Sweden has increased substantially during the last 30 years although incidence has been stable. Patients diagnosed in young adulthood were at a 12.7-fold increased risk of death, and male PBC patients had worse prognosis.

Celiac disease: a comprehensive current review

BACKGROUND

Celiac disease remains a challenging condition because of a steady increase in knowledge tackling its pathophysiology, diagnosis, management, and possible therapeutic options.

MAIN BODY

A major milestone in the history of celiac disease was the identification of tissue transglutaminase as the autoantigen, thereby confirming the autoimmune nature of this disorder. A genetic background (HLA-DQ2/DQ8 positivity and non-HLA genes) is a mandatory determinant of the development of the disease, which occurs with the contribution of environmental factors (e.g., viral infections and dysbiosis of gut microbiota). Its prevalence in the general population is of approximately 1%, with female predominance. The disease can occur at any age, with a variety of symptoms/manifestations. This multifaceted clinical presentation leads to several phenotypes, i.e., gastrointestinal, extraintestinal, subclinical, potential, seronegative, non-responsive, and refractory. Although small intestinal biopsy remains the diagnostic 'gold standard', highly sensitive and specific serological tests, such as tissue transglutaminase, endomysial and deamidated gliadin peptide antibodies, have become gradually more important in the diagnostic work-up of celiac disease. Currently, the only treatment for celiac disease is a life-long, strict gluten-free diet leading to improvement in quality of life, ameliorating symptoms, and preventing the occurrence of refractory celiac disease, ulcerative jejunoileitis, and small intestinal adenocarcinoma and lymphoma.

CONCLUSIONS

The present review is timely and provides a thorough appraisal of various aspects characterizing celiac disease. Remaining challenges include obtaining a better understanding of still-unclear phenotypes such as slow-responsive, potential (minimal lesions) and seronegative celiac disease. The identification of alternative or complementary treatments to the gluten-free diet brings hope for patients unavoidably burdened by diet restrictions.

Discordance Between Serology and Histology for Celiac Disease in a Cohort with Coexisting Liver Disorders

Background

The liver and celiac disease (CeD) share a complex relationship. While in some patients, isolated hypertransaminasemia is the only manifestation of CeD, liver diseases (LD) may also be associated with the presence of isolated tissue transglutaminase antibodies IgA (tTG IgA) without histologic evidence of CeD.

Aims

To examine the yield of tTG IgA testing (a) in the workup for chronic liver disease (CLD) or cytolysis and (b) to identify biopsy-confirmed CeD (BxCeD) among patients with concomitant LD.

Methods

Retrospective study including two cohorts. Cohort 1 represented 444 consecutive individuals without known CeD for which liver specialists requested tTG IgA. Incidence of positive tTG and BxCeD was evaluated. Cohort 2 included 212 consecutive individuals with positive tTG IgA and subsequent duodenal biopsies. The frequency and clinical characteristics of individuals without BxCeD were examined, with and without concurrent LD.

Results

The rate of first time positive tTG IgA among the tests requested by a liver specialist (cohort 1) was 2.0% (n = 9). However, 33.0% (n = 3) of these patients did not have BxCeD. Cohort 2 included 33 individuals with coexisting LD, of which 42.4% did not have BxCeD, compared with 16.2% of the patients without LD (P < 0.001). The majority of the patients without BxCeD (65.1%) showed an increase < 3 times upper limit of normal of tTG IgA.

Conclusions

Although there is clinical value in testing for CeD in the context of LD, there could be a high rate of positive CeD serology unaccompanied by histologic signs in patients with coexisting LD.

Small bowel adenocarcinoma as a complication of celiac disease: clinical and diagnostic features

BACKGROUND

Small bowel adenocarcinoma (SBA) is a rare neoplasm, which can occur in a sporadic form or can be associated with a number of predisposing conditions such as hereditary syndromes and immune-mediated intestinal disorders, e.g. celiac disease (CD). However, the features of SBA in the context of CD remain only partly understood. This study was aimed to show the main clinical features, diagnostic procedures and management options of SBA cases detected in a large cohort of celiac patients diagnosed in a single tertiary care center.

METHODS

We retrospectively reviewed all the SBA cases detected in a cohort of 770 CD patients (599 females; F / M ratio: 3.5:1; median age at diagnosis 36 years, range 18-80 years), diagnosed at the Celiac Disease Referral Center of our University Hospital (Bologna, Italy) from January 1995 to December 2014.

RESULTS

Five (0.65%) out of our 770 CD patients developed SBA. All of them were female with a mean age of 53 years (range 38-72 years). SBA, diagnosed at the same time of the CD diagnosis in three cases, was localized in the jejunum in four cases and in the duodenum in one case. The clinical presentation of SBA was characterized by intestinal sub-occlusion in two cases, while the predominant manifestation of the remaining three cases was iron deficiency anaemia, abdominal pain and acute intestinal obstruction, respectively. All the patients were referred to surgery, and three cases with advanced stage neoplasia were also treated with chemotherapy. The overall survival rate at 5 years was 80%.

CONCLUSIONS

Although in a limited series, herein presented CD-related SBA cases were characterized by a younger age of onset, a higher prevalence in female gender and a better overall survival compared to sporadic, Crohn- and hereditary syndrome-related SBA.

Autoimmunity in celiac disease: Extra-intestinal manifestations

Celiac disease is an autoimmune condition of the small intestine caused by prolamins in genetically susceptible individuals evoked by multiple environmental factors. The pathological luminal intricate eco-events produce multiple signals that irradiate the entire body, resulting in a plethora of extra-intestinal manifestations. Nutrients, dysbiosis, dysbiotic components and their mobilome, post-translational modification of naive proteins, inter-enterocyte's tight junction dysfunction resulting in a leaky gut, microbial lateral genetic transfer of virulent genes, the sensing network of the enteric nervous systems and the ensuing pro-inflammatory messengers are mutually orchestrating the autoimmune interplay. Genetic-environmental-luminal events-mucosal changes are driving centrifugally the remote organs autoimmunity, establishing extra-intestinal multi organ injury. Exploring the underlying intestinal eco-events, the sensing and the delivery pathways and mechanisms that induce the peripheral tissues' damages might unravel new therapeutical strategies to prevent and help the gluten affected patients.

Gut microbiota translocation promotes autoimmune cholangitis

Gut microbiota and bacterial translocation have been implicated as significant contributors to mucosal immune responses and tolerance; alteration of microbial molecules, termed pathogen-associated molecular patterns (PAMP) and bacterial translocation are associated with immune pathology. However, the mechanisms by which dysregulated gut microbiota promotes autoimmunity is unclear. We have taken advantage of a well-characterized murine model of primary biliary cholangitis, dnTGFβRII mice, and an additional unique construct, toll-like receptor 2 (TLR2)-deficient dnTGFβRII mice coined dnTGFβRIITLR2-/- mice to investigate the influences of gut microbiota on autoimmune cholangitis. Firstly, we report that dnTGFβRII mice manifest altered composition of gut microbiota and that alteration of this gut microbiota by administration of antibiotics significantly alleviates T-cell-mediated infiltration and bile duct damage. Second, toll-like receptor 2 (TLR2)-deficient dnTGFβRII mice demonstrate significant exacerbation of autoimmune cholangitis when their epithelial barrier integrity was disrupted. Further, TLR2-deficiency mediates downregulated expression of tight junction-associated protein ZO-1 leading to increased gut permeability and bacterial translocation from gut to liver; use of antibiotics reduces microbiota translocation to liver and also decreases biliary pathology. In conclusion, our data demonstrates the important role of gut microbiota and bacterial translocation in the pathogenesis of murine autoimmune cholangitis.

Bacteremia in Patients With Liver Cirrhosis: Prevalence and Predictors of Multidrug Resistant Organisms

GOALS

The objective of this study was to assess the prevalence and predictors of multidrug resistant organisms (MDRO) in cirrhotic patients with bacteremia at a large tertiary center in the United States.

BACKGROUND

The epidemiology of bacteremia in patients with liver cirrhosis has not been well studied in the United States.

STUDY

This case-case control study included 180 adults with liver cirrhosis hospitalized from 2011 to 2015. Case group 1 were patients with bacteremia due to a MDRO (n=30). Case group 2 were patients with bacteremia due to a non-MDRO (n=60). Control group comprised patients without bacteremia (n=90). MDRO was defined as bacteria that was nonsusceptible to ≥1 agent in ≥3 antimicrobial categories.

RESULTS

Of the 90 bacteremia episodes, 44% were because of gram-positive bacteria, 50% were because of gram-negative bacteria, and 6% were polymicrobial. MDROs caused 30 of 90 (33%) bacteremia episodes, including methicillin-resistant Staphylococcus species [12% (11/90)], fluoroquinolone-resistant Enterobacteriaceae [10% (9/90)], and Enterococcus faecium [3% (3/90)]. Eight percent of Enterobacteriaceae produced extended-spectrum β-lactamases. Four independent predictors of MDROs were identified: nonwhite race [adjusted odds ratio (aOR), 3.35; 95% confidence interval (CI), 1.19-9.38], biliary cirrhosis (aOR, 11.75; 95% CI, 2.08-66.32), blood cultures obtained >48 hours after hospital admission (aOR, 6.02; 95% CI, 1.70-21.40), and recent health care exposure (aOR, 9.81; 95% CI, 2.15-44.88).

CONCLUSIONS

A significant proportion of bacteremia in cirrhotic patients was due to MDROs at a large US tertiary care center. Local epidemiology data and identification of risk factors associated with MDROs may help with optimal empiric antibiotic selection.

Celiac Disease and Liver Disorders: From Putative Pathogenesis to Clinical Implications

Immunologically mediated liver diseases belong to the common extraintestinal manifestations of celiac disease. We have reviewed the current literature that addresses the association between celiac disease and liver disorders. We searched relevant articles on MEDLINE/PubMed up to 15 June 2018. The objective of the article is to provide a comprehensive and up-to-date review on the latest hypotheses explaining the pathogenetic relationship between celiac disease and liver injury. Besides the involvement of gut–liver axis, tissue transglutaminase antibodies, and impairment of intestinal barrier, we integrate the latest achievements made in elucidation of the role of gut microbiota in celiac disease and liver disorders, that has not yet been sufficiently discussed in the literature in this context. The further objective is to provide a complete clinical overview on the types of liver diseases frequently found in celiac disease. In conclusion, the review highlights the clinical implication, recommend a rational approach for managing elevated transaminases in celiac patients, and underscore the importance of screening for celiac disease in patients with associated liver disease.

Alcohol Modulation of the Postburn Hepatic Response

The widespread and rapidly increasing trend of binge drinking is accompanied by a concomitant rise in the prevalence of trauma patients under the influence of alcohol at the time of their injury. Epidemiological evidence suggests up to half of all adult burn patients are intoxicated at the time of admission, and the presence of alcohol is an independent risk factor for death in the early stages post burn. As the major site of alcohol metabolism and toxicity, the liver is a critical determinant of postburn outcome, and experimental evidence implies an injury threshold exists beyond which burn-induced hepatic derangement is observed. Alcohol may lower this threshold for postburn hepatic damage through a variety of mechanisms including modulation of extrahepatic events, alteration of the gut-liver axis, and changes in signaling pathways. The direct and indirect effects of alcohol may prime the liver for the second-hit of many overlapping physiologic responses to burn injury. In an effort to gain a deeper understanding of how alcohol potentiates postburn hepatic damage, the authors summarize possible mechanisms by which alcohol modulates the postburn hepatic response.

Why Doesn't Primary Biliary Cholangitis Respond to Immunosuppressive Medications?

Purpose of Review

The purpose of this review is to discuss reasons why immunosuppressive therapy so far failed in Primary Biliry Cholangitis.

Recent Findings

Even targeted immunosuppressive therapy seems ineffective or potentially harmful.

Summary

Bile acid-mediated cholangiocyte damage, facilitated by insufficient bicarbonate secretion, seems to attenuate the anti-inflammatory and anti-fibrotic actions of immunosuppressant and immunomodulatory drugs in a clinically significant way.

Recent advances in the diagnosis and treatment of primary biliary cholangitis

Primary biliary cholangitis (PBC), formerly referred to as primary biliary cirrhosis, is an infrequent progressive intrahepatic cholestatic autoimmune illness that can evolve into hepatic fibrosis, hepatic cirrhosis, hepatic failure, and, in some cases, hepatocellular carcinoma. The disease itself is characterized by T-lymphocyte-mediated chronic non-suppurative destructive cholangitis and elevated serum levels of extremely specific anti-mitochondrial autoantibodies (AMAs). In this article, we will not only review epidemiology, risk factors, natural history, predictive scores, radiologic approaches (e.g., acoustic radiation force impulse imaging, vibration controlled transient elastography, and magnetic resonance elastography), clinical features, serological characteristics covering biochemical markers, immunoglobulins, infections markers, biomarkers, predictive fibrosis marker, specific antibodies (including AMAs such as AMA-M2), anti-nuclear autoantibodies [such as anti-multiple nuclear dot autoantibodies (anti-sp100, PML, NDP52, anti-sp140), anti-rim-like/membranous anti-nuclear autoantibodies (anti-gp210, anti-p62), anti-centromere autoantibodies, and some of the novel autoantibodies], histopathological characteristics of PBC, diagnostic advances, and anti-diastole of PBC. Furthermore, this review emphasizes the recent advances in research of PBC in terms of therapies, including ursodeoxycholic acid, budesonide, methotrexate, obeticholic acid, cyclosporine A, fibrates such as bezafibrate and fenofibrate, rituximab, mesenchymal stem cells transplant, and hepatic transplant. Currently, hepatic transplant remains the only optimal choice with acknowledged treatment efficiency for end-stage PBC patients.

Fish gut-liver immunity during homeostasis or inflammation revealed by integrative transcriptome and proteome studies

The gut-associated lymphoid tissue, connected with liver via bile and blood, constructs a local immune environment of both defense and tolerance. The gut-liver immunity has been well-studied in mammals, yet in fish remains largely unknown, even though enteritis as well as liver and gallbladder syndrome emerged as a limitation in aquaculture. In this study, we performed integrative bioinformatic analysis for both transcriptomic (gut and liver) and proteomic (intestinal mucus and bile) data, in both healthy and infected tilapias. We found more categories of immune transcripts in gut than liver, as well as more adaptive immune in gut meanwhile more innate in liver. Interestingly reduced differential immune transcripts between gut and liver upon inflammation were also revealed. In addition, more immune proteins in bile than intestinal mucus were identified. And bile probably providing immune effectors to intestinal mucus upon inflammation was deduced. Specifically, many key immune transcripts in gut or liver as well as key immune proteins in mucus or bile were demonstrated. Accordingly, we proposed a hypothesized profile of fish gut-liver immunity, during either homeostasis or inflammation. Current data suggested that fish gut and liver may collaborate immunologically while keep homeostasis using own strategies, including potential unique mechanisms.

Dysbiosis of small intestinal microbiota in liver cirrhosis and its association with etiology

Cirrhosis-associated duodenal dysbiosis is not yet clearly defined. In this research, duodenal mucosal microbiota was analyzed in 30 cirrhotic patients and 28 healthy controls using 16S rRNA gene pyrosequencing methods. The principal coordinate analysis revealed that cirrhotic patients were colonized by remarkable different duodenal mucosal microbiota in comparison with controls. At the genus level, Veillonella, Megasphaera, Dialister, Atopobium, and Prevotella were found overrepresented in cirrhotic duodenum. And the duodenal microbiota of healthy controls was enriched with Neisseria, Haemophilus, and SR1 genera incertae sedis. On the other hand, based on predicted metagenomes analyzed, gene pathways related to nutrient absorption (e.g. sugar and amino acid metabolism) were highly abundant in cirrhosis duodenal microbiota, and functional modules involved in bacterial proliferation and colonization (e.g. bacterial motility proteins and secretion system) were overrepresented in controls. When considering the etiology of cirrhosis, two operational taxonomic units (OTUs), OTU-23 (Neisseria) and OTU-36 (Gemella), were found discriminative between hepatitis-B-virus related cirrhosis and primary biliary cirrhosis. The results suggest that the structure of duodenal mucosa microbiota in cirrhotic patients is dramatically different from healthy controls. The duodenum dysbiosis might be related to alterations of oral microbiota and changes in duodenal micro-environment.

The management of autoimmunity in patients with cholestatic liver diseases

Cholestatic liver diseases are rare diseases that often lead to cirrhosis and its consequent complications. In addition to liver-related morbidity, patients with cholestatic liver diseases often suffer from autoimmune diseases that affect several organs and tissues. The robust and efficient data collection and collaboration between hepatologists and rheumatologists have led to significant advancements in understanding the relationship between the cholestatic liver diseases and associated autoimmune diseases. In this paper, we discuss the cholestatic liver diseases (primary biliary cirrhosis, primary sclerosing cholangitis and immunoglobulin G4 associated cholangitis) and associated autoimmune diseases.

Alcohol and lung injury and immunity

Annually, excessive alcohol use accounts for more than $220 billion in economic costs and 80,000 deaths, making excessive alcohol use the third leading lifestyle-related cause of death in the US. Patients with an alcohol-use disorder (AUD) also have an increased susceptibility to respiratory pathogens and lung injury, including a 2-4-fold increased risk of acute respiratory distress syndrome (ARDS). This review investigates some of the potential mechanisms by which alcohol causes lung injury and impairs lung immunity. In intoxicated individuals with burn injuries, activation of the gut-liver axis drives pulmonary inflammation, thereby negatively impacting morbidity and mortality. In the lung, the upper airway is the first checkpoint to fail in microbe clearance during alcohol-induced lung immune dysfunction. Brief and prolonged alcohol exposure drive different post-translational modifications of novel proteins that control cilia function. Proteomic approaches are needed to identify novel alcohol targets and post-translational modifications in airway cilia that are involved in alcohol-dependent signal transduction pathways. When the upper airway fails to clear inhaled pathogens, they enter the alveolar space where they are primarily cleared by alveolar macrophages (AM). With chronic alcohol ingestion, oxidative stress pathways in the AMs are stimulated, thereby impairing AM immune capacity and pathogen clearance. The epidemiology of pneumococcal pneumonia and AUDs is well established, as both increased predisposition and illness severity have been reported. AUD subjects have increased susceptibility to pneumococcal pneumonia infections, which may be due to the pro-inflammatory response of AMs, leading to increased oxidative stress.

Celiac disease-related hepatic injury: Insights into associated conditions and underlying pathomechanisms

BACKGROUND

Celiac disease (CD) is the most common autoimmune enteropathy. Clinical manifestations may range from a typical malabsorption syndrome to several apparently unrelated extra-intestinal symptoms.

AIM

Here we specifically focus on the spectrum of CD-related liver disorders and the underlying pathomechanisms.

METHODS

A computer-based search up to August 2015 was completed using appropriate keywords. References from selected papers were also reviewed and used if relevant.

RESULTS

An unexplained hypertransaminasemia with nonspecific histologic hepatic changes is the most common hepatic presentation. CD however can coexist with a number of liver disorders such as Autoimmune Hepatitis, Autoimmune Cholangitis, Primary Biliary Cirrhosis and Primary Sclerosing Cholangitis requiring a specific treatment in addition to gluten-free diet. CD has also been associated with Viral Hepatitis, Fatty Liver, Non-Alcoholic Steatohepatitis and some severe cryptogenic hepatopaties in the liver transplantation list. Pathomechanisms underlying hepatic injury in CD are multiple, appear still not completely defined and may probably co-occur.

CONCLUSIONS

An ever-increasing number of CD-related liver injuries exist, probably representing a continuum of a same disorder where genetic predisposition, timing, and duration of previous gluten exposure might influence the reversibility of liver damage. Evidences, although not conclusive, support therefore testing for CD also in cryptogenic hepatobiliary conditions where the relationship with CD has not yet been fully investigated.

Prevalence of abnormal liver function tests in celiac disease and the effect of a gluten-free diet in the US population

OBJECTIVES

Guidelines recommend routine screening of liver function tests (LFTs) in patients diagnosed with celiac disease (CD). However, little is known about the prevalence of liver disorders in CD outside of Europe. Our aims were to estimate the prevalence of LFT abnormalities in CD and to evaluate the effect of a gluten-free diet (GFD) on LFTs.

METHODS

Adult patients with biopsy-proven CD were identified from a prospectively maintained database and matched with healthy controls. LFT levels for women and men were defined as abnormal based on the Third National Health and Nutrition Examination Survey (NHANES III) criteria. Data on demographics, coexisting liver diseases, and laboratory work-ups including aspartate transaminase (AST) and alanine transaminase (ALT) values at the time of diagnosis and on a GFD were recorded. Subsequently, data from this cohort were compared with data from 7,789 individuals participating in the National Health and Nutrition Examination Survey, 2009-2010. Univariate logistic regression, Wilcoxon signed-ranks, Student's t-test, χ(2), and Fischer's exact test were used for statistical analysis.

RESULTS

In 463 CD patients with ALT or AST levels at the time of CD diagnosis, 40.6% had elevated LFTs compared with 24.2% of treated CD patients (P<0.001) and 16.6% of matched controls (P<0.001). Similarly, 36.7% of CD patients on the NHANES database had abnormal ALT values compared with 19.3% of non-celiac patients (P=0.03). Approximately, 78.6% of CD patients with elevated LFTs at diagnosis normalized LFTs on a GFD after a mean duration of 1.5±1.5 years.

CONCLUSIONS

Forty percent of individuals will have elevated LFTs at CD diagnosis; however, the majority will normalize with standard CD therapy. LFTs should be checked in all patients with CD and coexisting liver disorder should be considered in patients whose LFTs have not improved within a year on a GFD.

Hepatic hemangioma in celiac patients: data from a large consecutive series

Background and Aims. Hepatic hemangioma (HH) has a widely ranging prevalence. The etiology is unclear; however, associations with autoimmune disorders have been described. We aimed at evaluating the prevalence of HH in celiac disease. Methods. Ninety-seven consecutive patients with celiac disease (18 M, 79 F, median age 41, and range 17-84 years) underwent liver ultrasound between January 2011 and 2012. The findings were compared with those of 1352 nonceliac patients (581 M, 771 F, median age 50, and range 16-94 years), without liver disease or previously detected HH, who underwent US in the same period. Results. Ultrasonographic findings consistent with HH were observed in 14 celiac patients (14.4%), a prevalence significantly higher than in controls (69 cases, 5.1%) (P = 0.0006). Subgroup analysis showed that, among women, the prevalence of HH was 16.4% in the celiac disease group (13/79) compared with 5.9% in controls (46/771) (P = 0.002). In celiac setting, HH had a median diameter of 1.3 cm and presented as a single lesion in 12 cases (86%). Conclusions. Our findings are consistent with a significantly higher prevalence of HH in celiac patients. Although mechanisms underlying this association remain unclear, autoimmune and metabolic processes, as well as alterations of gut-liver axis equilibrium, could play a role.

An alteration of the gut-liver axis drives pulmonary inflammation after intoxication and burn injury in mice

Approximately half of all adult burn patients are intoxicated at the time of their injury and have worse clinical outcomes than those without prior alcohol exposure. This study tested the hypothesis that intoxication alters the gut-liver axis, leading to increased pulmonary inflammation mediated by burn-induced IL-6 in the liver. C57BL/6 mice were given 1.2 g/kg ethanol 30 min prior to a 15% total body surface area burn. To restore gut barrier function, the specific myosin light chain kinase inhibitor membrane-permeant inhibitor of kinase (PIK), which we have demonstrated to reduce bacterial translocation from the gut, was administered 30 min after injury. Limiting bacterial translocation with PIK attenuated hepatic damage as measured by a 47% reduction in serum alanine aminotransferase (P < 0.05), as well as a 33% reduction in hepatic IL-6 mRNA expression (P < 0.05), compared with intoxicated and burn-injured mice without PIK. This mitigation of hepatic damage was associated with a 49% decline in pulmonary neutrophil infiltration (P < 0.05) and decreased alveolar wall thickening compared with matched controls. These results were reproduced by prophylactic reduction of the bacterial load in the intestines with oral antibiotics before intoxication and burn injury. Overall, these data suggest that the gut-liver axis is deranged when intoxication precedes burn injury and that limiting bacterial translocation in this setting attenuates hepatic damage and pulmonary inflammation.

Oversecretion of soluble CTLA-4 in various autoimmune diseases overlapping celiac disease

AIM

To evaluate the levels of soluble CTLA-4 (sCTLA-4) in sera of celiac disease (CD) patients with overlapping autoimmune diseases (OAD; diabetes mellitus, autoimmune thyroid diseases, inflammatory bowel diseases, and autoimmune polyendocrine syndromes).

METHODS

Sera from Italian patients with CD were obtained and enzyme-linked immunosorbent assay was used to measure sCTLA-4.

RESULTS

Consistently high serum sCTLA-4 levels were observed in CD (13.20 ng/mL, p<0.0001) and OAD (19.48 ng/mL, p<0.0001) compared to normal controls. A significant increase in the level of serum sCTLA-4 was observed in OAD (p=0.0273) compared to CD alone. At variance, no significant difference in the sCTLA-4 levels was observed when single OAD were compared.

CONCLUSION

The present study shows for the first time a statistically significant increase of serum sCTLA-4 levels in CD patients with associated autoimmune disease (namely, CD and OAD) versus patients with CD alone. Previously, the potential genetic associations of several CTLA-4 polymorphisms to susceptibility to autoimmune diseases have been described, although the relationship between CTLA-4 polymorphisms and the ability to produce the soluble form is not fully clarified. CTLA-4 is a strong actor in the adaptive response: our data give supportive evidence of the common background of autoimmune diseases.

Liver abnormalities in bowel diseases

Liver abnormalities are often seen in bowel diseases. Whether these represent aspects of two separate diseases, or if one is causing the other, is not always easy to decide. Extraintestinal manifestations of inflammatory bowel disease (IBD) or coeliac disease are frequently observed. Of these extraintestinal manifestations, hepatic disorders are among the most common. Primary sclerosing cholangitis (PSC) and primary biliary cirrhosis are the most frequent hepatic disorders in IBD and coeliac disease, respectively. Genetic studies have lately elucidated the associations between IBD and PSC, but there is still a long way until we have complete understanding of the molecular aetiology and pathophysiology of these conditions. There is no curative treatment available for PSC, besides liver transplantation. Steatosis and cholelithiasis are also common in IBD, as are signs of hepatic injury due to IBD treatment. Less common liver abnormalities include liver abscesses, hepatic thromboembolic events, granulomatous liver disease and hepatic amyloidosis.

Celiac disease and autoimmune-associated conditions

Celiac disease (CD) is frequently accompanied by a variety of extradigestive manifestations, thus making it a systemic disease rather than a disease limited to the gastrointestinal tract. This is primarily explained by the fact that CD belongs to the group of autoimmune diseases. The only one with a known etiology is related to a permanent intolerance to gluten. Remarkable breakthroughs have been achieved in the last decades, due to a greater interest in the diagnosis of atypical and asymptomatic patients, which are more frequent in adults. The known presence of several associated diseases provides guidance in the search of oligosymptomatic cases as well as studies performed in relatives of patients with CD. The causes for the onset and manifestation of associated diseases are diverse; some share a similar genetic base, like type 1 diabetes mellitus (T1D); others share pathogenic mechanisms, and yet, others are of unknown nature. General practitioners and other specialists must remember that CD may debut with extraintestinal manifestations, and associated illnesses may appear both at the time of diagnosis and throughout the evolution of the disease. The implementation of a gluten-free diet (GFD) improves the overall clinical course and influences the evolution of the associated diseases. In some cases, such as iron deficiency anemia, the GFD contributes to its disappearance. In other disorders, like T1D, this allows a better control of the disease. In several other complications and/or associated diseases, an adequate adherence to a GFD may slow down their evolution, especially if implemented during an early stage.