[Incidence and prevalence of autoimmune hepatitis in the area of the Hospital de Sagunto (Spain)]

Mechanism of Action of Dihydroquercetin in the Prevention and Therapy of Experimental Liver Injury

Liver disease is a global health problem that affects the well-being of tens of thousands of people. Dihydroquercetin (DHQ) is a flavonoid compound derived from various plants. Furthermore, DHQ has shown excellent activity in the prevention and treatment of liver injury, such as the inhibition of hepatocellular carcinoma cell proliferation after administration, the normalization of oxidative indices (like SOD, GSH) in this tissue, and the down-regulation of pro-inflammatory molecules (such as IL-6 and TNF-α). DHQ also exerts its therapeutic effects by affecting molecular pathways such as NF-κB and Nrf2. This paper discusses the latest research progress of DHQ in the treatment of various liver diseases (including viral liver injury, drug liver injury, alcoholic liver injury, non-alcoholic liver injury, fatty liver injury, and immune liver injury). It explores how to optimize the application of DHQ to improve its effectiveness in treating liver diseases, which is valuable for preparing potential therapeutic drugs for human liver diseases in conjunction with DHQ.

Advances in the evaluation and treatment of autoimmune hepatitis

PURPOSE OF REVIEW

The primary therapy of autoimmune hepatitis (AIH) has been established for over three decades. This review focuses on updates in the evaluation and management of patients with AIH.

RECENT FINDINGS

The evaluation of patients has recently been updated to include more definitive screening for other autoimmune diseases, including thyroid disease and celiac disease. Antibody detection by ELISA, an easier and more commonly available method, has been incorporated into the latest iteration of the AIH scoring system. Corticosteroids and AZA remain the backbone of AIH treatment, but there is growing evidence for mycophenolate mofetil as both first-line and second-line therapy, and growing inquiry into calcineurin inhibitors. Noninvasive markers of liver disease have now been validated in AIH, with the strongest evidence for VCTE in patients with minimal hepatic inflammation.

SUMMARY

Recent research of alternative immunosuppressant therapies, noninvasive markers of fibrosis, and updated society guidelines, have improved our ability to evaluate, treat, and follow patients with AIH.

Global incidence and prevalence of autoimmune hepatitis, 1970-2022: a systematic review and meta-analysis

Background

Autoimmune hepatitis (AIH) varies significantly in incidence and prevalence across countries and regions. We aimed to examine global, regional, and national trends in incidence and prevalence of AIH from 1970 to 2022.

Methods

We conducted a thorough search of the PubMed/MEDLINE, Embase, CINAHL, Google Scholar, and Cochrane databases from database inception to August 9, 2023, using the search term "autoimmune hepatitis" in combination with "incidence," "prevalence," or "trend." Only general population-based observational studies with larger samples sizes were considered for inclusion. Studies that recruited convenience samples, and those with fewer than 50 participants were excluded. Summary data were extracted from published reports. A random effects model was used and pooled estimates with 95% CI were used to calculate the incidence and prevalence of AIH. Heterogeneity was evaluated using the I2 statistic. The study protocol was registered with PROSPERO, CRD42023430138.

Findings

A total of 37 eligible studies, encompassing more than 239 million participants and 55,839 patients with AIH from 18 countries across five continents, were included in the analysis. Global pooled incidence and prevalence of AIH were found to be 1.28 cases per 100,000 inhabitant-years (95% CI, 1.01-1.63, I2 = 99·51%; number of studies, 33; sample population, 220,673,674) and 15.65 cases per 100,000 inhabitants (95% CI, 13.42-18.24, I2 = 99·75%; number of studies, 26; sample population, 217,178,684), respectively. The incidence of AIH was greater in countries with high Human Development Index (>0.92), in North America and Oceania (compared with Asia), among females, adults (compared with children), and high latitude (>45°). Similar patterns in AIH prevalence were observed. Pooled AIH prevalence increased gradually from 1970 to 2019 (1970-1999; 9.95 [4.77-15.13], I2 = 95·58% versus 2015-2022; 27.91 [24.86-30.96], I2 = 99·32%; cases per 100,000 inhabitants). The overall incidence and prevalence of AIH, as well as some subgroup analyses of the studies, displayed asymmetry in the funnel plots, suggesting potential evidence of publication bias.

Interpretation

AIH incidence and prevalence have increased significantly and exhibit substantial variation across regions worldwide. Further research is required to assess the incidence and prevalence of AIH, specifically in South America and Africa.

Funding

National Research Foundation of Korea.

Epidemiology and surveillance of autoimmune hepatitis in Asia

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease that mainly injures the hepatocytes. The autoimmune disease might be involved in its aetiology, but this remains to be confirmed. Recently epidemiological studies of AIH in Asia have been broadly conducted, revealing characteristics and management of AIH patients in Asia. In East Asia, most AIH patients are type 1, and type 2 AIH is very rare. However, type 2 AIH in South Asia is as frequent as in Europe and the USA. HLA-DR4 is associated with the characteristics of type 1 AIH in East Asia, whereas HLA-DR3 occurs in AIH patients from South Asia. AIH prevalence worldwide is increasing, and several studies have reported a prevalence of 19.44, 22.80 and 12.99 per 100 000 people in Europe, the USA and Asia respectively. A meta-analysis of studies on AIH showed similar annual incidence rates for all regions, with 1.31, 1.37 and 1.00 per 100 000 people in Asia, Europe and the USA respectively. The increase in the rates could be attributable to the increased awareness of disease concepts and diagnosis. In South Asia, most cases were diagnosed as AIH only after having progressed to cirrhosis, which may cause a higher mortality rate in South Asia than in East Asia. Therefore, the early diagnosis and treatment of AIH patients can improve the current situation in Asia.

Presentation and Outcomes of Autoimmune Hepatitis Type 1 and Type 2 in Children: A Single-center Study

OBJECTIVE

Autoimmune hepatitis (AIH) is designated as type 1 or 2 (AIH-1/2) on the basis of serum autoantibody (Ab) profiles. In children, AIH may present as acute or chronic liver failure or cirrhotic AIH (ALF/CLF/CAIH) with or without overlap sclerosing cholangitis (SC). The aim of this study was to compare demographics, presentation, and outcomes between groups in children.

METHODS

A retrospective electronic chart review of children with AIH who met standard diagnostic criteria with histologic confirmation at Texas Children's Hospital was performed, with de novo AIH after liver transplant (LT) excluded. Patients were identified and divided into AIH-1, AIH-2, ALF, CAIH, AIH-SC, and LT and compared using chi-square analysis, Student t-test, and Mood median test.

RESULTS

Among 91 children with AIH, 72 (79.1%) had AIH-1, 19 (20.9%) had AIH-2, 13 (14.3%) had ALF, 25 (27.5%) had CAIH, and 14 (15.4%) had AIH-SC. Both AIH-1/2 had female and Hispanic predominance (72.2/89.5%, 40.3/57.9%). AIH-2 presented at younger mean age in years than AIH-1 (6.8, 12.1, P < 0.05). Both AIH-1/2 had low rates of remission after 1 year of IS (25.4, 35.7%) and most recent (30.6, 54.5%) follow-up. Twenty-two (24.2) patients received LT: 16 had AIH-1 (72.7%), 6 had AIH-2 (27.3%), 9 (40.9%) had ALF, and 13 (59.1%) had CAIH. One-year patient and graft survivals were 100%.

CONCLUSIONS

The epidemiology and clinical presentation of AIH-1 and -2 had a few subtle differences. AIH-1 was associated with more complications after LT. More data are needed to better characterize the 2 as separate disease entities.

Incidence, prevalence and mortality of autoimmune hepatitis in England 1997-2015. A population-based cohort study

BACKGROUND & AIMS

There are few population-based studies of the incidence and mortality of autoimmune hepatitis. The burden of the disease and how it has changed over time have not been fully explored. We conducted a population-based cohort study on the incidence and mortality of autoimmune hepatitis in England, 1997-2015.

METHODS

From the Clinical Practice Research Datalink we included 882 patients diagnosed with autoimmune hepatitis in England, 1997-2015. The patients were followed through 2015, and we calculated the sex- and age-standardized incidence and prevalence of autoimmune hepatitis. We examined variation in incidence by sex, age, calendar year, geographical region and socioeconomic status, and incidence rate ratios were calculated with Poisson regression. We calculated all-cause and cause-specific mortality.

RESULTS

The overall standardized incidence rate of autoimmune hepatitis was 2.08 (95% confidence interval 1.94-2.22) per 100,000 population per year, higher in women, higher in older age and independent of region and socioeconomic status. From 1997 to 2015 the incidence doubled from 1.27 (95% confidence interval 0.51-2.02) to 2.56 (95% confidence interval 1.79-3.33) per 100,000 population per year. The 10-year cumulative all-cause mortality was 31.9% (95% confidence interval 27.6-36.5), and the 10-year cumulative liver-related mortality, including hepatocellular carcinoma was ~10.5%.

CONCLUSIONS

This population-based study showed that the incidence of autoimmune hepatitis doubled over an eighteen-year period. The incidence was particularly high in older women and was similar across all regions of England and independent of socioeconomic status. Patients with autoimmune hepatitis had a high mortality.

Increased incidence of autoimmune hepatitis is associated with wider use of biological drugs

BACKGROUND & AIMS

Population-based studies on the epidemiology of autoimmune hepatitis (AIH) are scarce. Drug-induced AIH (DIAIH) is increasingly recognized in association with immunomodulatory therapy. We aimed to determine the incidence, prevalence and natural history of AIH in a population-based setting.

METHODS

We collected data of new diagnosis of AIH in Iceland from 2006 to 2015. Cases were identified through search of diagnostic codes and text search for AIH within electronical medical records of all hospitals in Iceland and through records of smooth muscle antibodies (SMA) test results by the only laboratory in the country analyzing SMA. Patients were included in the final analysis if they received the clinical diagnosis of AIH or were started on immunosuppressive therapy.

RESULTS

The mean annual incidence of AIH in Iceland was 2.2 cases per 100 000 inhabitants. Point prevalence on 31 December 2015 was 27/100 000. The median age at diagnosis was 56 years and 86% of patients were of female gender. DIAIH was suspected in 13 of 71 patients (18%) of which eight cases were related to infliximab. Immunosuppressive treatment was started in all but two patients. At the end of follow-up (median 4.8 years) 66 of 71 (93%) patients were alive.

CONCLUSION

The incidence and prevalence rates of AIH in Iceland are the highest reported so far in a population-based setting. Higher incidence can partly be explained by the increasing use of biological drugs. Immunosuppressive therapy was very effective in achieving remission and prognosis was favorable.

Systematic review and meta-analysis on the incidence and prevalence of autoimmune hepatitis in Asian, European, and American population

BACKGROUND AND AIM

Reported incidence and prevalence rates of autoimmune hepatitis (AIH) have been sparse and heterogeneous. The aim of this meta-analysis was to estimate the worldwide incidence and prevalence rates of AIH and reveal population difference.

METHODS

Published articles on the epidemiology of AIH in PubMed, Embase, and Cochrane Library were systematically searched from inception to April 28, 2019. Two investigators independently reviewed these literatures and evaluated their quality. A random-effects model was used to pool the overall incidence and prevalence rates. The impact of population difference, gender, age, study period, study quality, diagnostic criteria, and study design was further analyzed with subgroup analysis and meta-regression.

RESULTS

A total of 22 studies were included in the meta-analysis. The pooled worldwide annual incidence and prevalence of AIH were 1.37 (95% confidence interval [CI]: 0.95-1.80) and 17.44 (95% CI: 12.01-22.87) per 100 000 persons, respectively. Subgroup analysis showed that the pooled annual incidence for Asian, European, and American population was 1.31 (95% CI: 0.42-2.20), 1.37 (95% CI: 1.10-1.64), and 1.00 (95% CI: 0.44-1.56) per 100 000 persons, respectively; the pooled prevalence for Asian, European, and American population was 12.99 (95% CI: 2.05-23.92), 19.44 (95% CI: 15.63-23.24), and 22.80 (95% CI: -13.48 to 59.07) per 100 000 persons, respectively. In addition, higher incidence and prevalence rates were observed in women than men, and a higher prevalence rate was observed in elderly than young people.

CONCLUSIONS

Autoimmune hepatitis is a rare disease, with a similar incidence worldwide and a higher prevalence in European and American than in Asian population.

Incidence, prevalence, and causes of death of patients with autoimmune hepatitis: A nationwide register-based cohort study in Finland

BACKGROUND

Epidemiological studies of autoimmune hepatitis are scarce and often based on single centre registries.

AIMS

We conducted a nationwide register study of incidence, prevalence, survival, and causes of death of autoimmune hepatitis patients in Finland.

METHODS

Autoimmune hepatitis cases 1995-2015 were retrieved from the national database of special reimbursements for drugs costs. Data on causes of death were retrieved from Statistics Finland.

RESULTS

After incomplete registration of AIH during the first years, the incidence of autoimmune hepatitis stabilised to 1.1/100,000 person-years (1.6 in women and 0.52 in men) in 2008-2015. The prevalence of autoimmune hepatitis at the end of 2015 was 14.3/100,000, 23.0/100,000 in women and 6.6/100,000 in men. The all-cause standardized mortality ratio (SMR) of autoimmune hepatitis patients was 1.81 (95% confidence interval (CI) 1.47-2.20). The SMR was increased in all age groups and in both sexes. The SMR for hepatocellular carcinoma was 20.6 (95% CI 10.3-36.8), and for digestive diseases in overall 13.5 (95% CI 8.2-20.8), constituting mainly from autoimmune hepatitis and liver cirrhosis.

CONCLUSION

Incidence of autoimmune hepatitis has remained stable, with clear female predominance. Autoimmune hepatitis is associated with a markedly increased risk of death with hepatocellular cancer forming the greatest risk.

Diagnosis, presentation and initial severity of Autoimmune Hepatitis (AIH) in patients attending 28 hospitals in the UK

BACKGROUND & AIMS

There is limited information regarding patients with AIH outside relatively few large centres. We describe here the presenting features of patients with AIH, collected as part of an audit involving 28 UK hospitals.

METHODS

Patients (incident since 1/1/2007 or prevalent since 1/1/2000) were ≥18 years and either met 1999 International AIH Group (IAIHG) diagnostic criteria (n = 1164), or received immunosuppressive therapy for clinically diagnosed AIH (n = 103).

RESULTS

Of 1267 patients (80% women, 91% Caucasian, age (median(range)) 55(8-86) years, 0.5% had acute viral hepatitis (CMV/EBV/HEV); 2% were taking Nitrofurantoin and 0.7% Khat. Twenty-one percent had clinical decompensation and/or a MELD score of >15. Time from first abnormal liver tests to diagnosis was ≥1 year in 19% and was longer in jaundiced vs non-jaundiced patients. HBV and HCV serology were undocumented in 4%, serum immunoglobulins in 31% and autoantibodies in 11%-27%. When documented, ≥1 antibody was present in 83%. LKM-1-positive and autoantibody-negative patients had more severe disease. Histological cirrhosis was reported in 23%, interface hepatitis 88%, predominant lymphocytes/plasma cells 75%, rosettes 19% and emperipolesis 0.4%. Only 65% of those meeting 1999 IAIHG criteria also met simplified IAIHG criteria. University Hospitals compared to District General Hospitals, were more likely to report histological features of AIH.

CONCLUSIONS

This cohort from across the UK is older than other multicentre AIH cohorts. One-fifth had decompensation or MELD >15. Diagnosis was delayed in 19%, diagnostic testing was incomplete in one-third and rosettes and emperipolesis were infrequently reported.

The Importance of Sex Stratification in Autoimmune Disease Biomarker Research: A Systematic Review

The immune system is highly dynamic and regulated by many baseline characteristic factors. As such, significant variability may exist among different patient groups suffering from the same autoimmune disease (AD). However, contemporary research practices tend to take the reductionist aggregate approach: they do not segment AD patients before embarking on biomarker discovery. This approach has been productive: many novel AD biomarkers have recently been discovered. Yet, subsequent validation studies of these biomarkers tend to suffer from a lack of specificity, sensitivity, and reproducibility which hamper their translation for clinical use. To enhance reproducibility in validation studies, an optimal discovery-phase study design is paramount: one which takes into account different parameters affecting the immune system biology. In this systematic review, we highlight need for stratification in one such parameter, i.e., sex stratification. We will first explore sex differences in immune system biology and AD prevalence, followed by reported sex-bias in the clinical phenotypes of two ADs—one which more commonly affects females: systemic lupus erythematosus, and one which more commonly affects males: ankylosing spondylitis. The practice of sex stratification in biomarker research may not only advance the discovery of sex-specific AD biomarkers but more importantly, promote reproducibility in subsequent validation studies, thus easing the translation of these novel biomarkers from bench to bedside to improve AD diagnosis. In addition, such practice will also promote deeper understanding for differential AD pathophysiology in males and females, which will be useful for the development of more effective interventions for each sex type.

Autoimmune liver disease and the enteric microbiome

The human enteric microbiome is highly complex and has more than 150 times more genes within it than its host. The host and the microbiome have a commensurate relationship that can evolve over time. The typically symbiotic relationship between the two can become pathogenic. The microbiome composition in adults reflects their history of exposure to bacteria and environmental factors during early life, their genetic background, age, interactions with the immune system, geographical location, and, most especially, their diet. Similarly, these factors are thought to contribute to the development of autoimmune disease. It is possible that alterations in the intestinal microbiome could lead to liver disease. There is emerging data for the contribution of the microbiome in development of primary sclerosing cholangitis, primary biliary cholangitis, and autoimmune hepatitis; liver disorders associated with aberrant immune function in genetically susceptible individuals.

Autoimmune hepatitis

Autoimmune hepatitis (AIH) is a severe liver disease that affects children and adults worldwide. The diagnosis of AIH relies on increased serum transaminase and immunoglobulin G levels, presence of autoantibodies and interface hepatitis on liver histology. AIH arises in genetically predisposed individuals when a trigger, such as exposure to a virus, leads to a T cell-mediated autoimmune response directed against liver autoantigens; this immune response is permitted by inadequate regulatory immune control leading to a loss of tolerance. AIH responds favourably to immunosuppressive treatment, which should be started as soon as the diagnosis is made. Standard regimens include fairly high initial doses of corticosteroids (prednisone or prednisolone), which are tapered gradually as azathioprine is introduced. For those patients who do not respond to standard treatment, second-line drugs should be considered, including mycophenolate mofetil, calcineurin inhibitors, mechanistic target of rapamycin (mTOR) inhibitors and biologic agents, which should be administered only in specialized hepatology centres. Liver transplantation is a life-saving option for those who progress to end-stage liver disease, although AIH can recur or develop de novo after transplantation. In-depth investigation of immune pathways and analysis of changes to the intestinal microbiota should advance our knowledge of the pathogenesis of AIH and lead to novel, tailored and better tolerated therapies.

Hospitalizations for Autoimmune Hepatitis Disproportionately Affect Black and Latino Americans

OBJECTIVES

The healthcare burden of autoimmune hepatitis (AIH) in the United States has not been characterized. We previously showed that AIH disproportionately affects people of color in a single hospital system. The current study aimed to determine whether the same disparity occurs nationwide.

METHODS

We analyzed hospitalizations with a primary discharge diagnosis corresponding to the ICD-9 code for AIH in the National Inpatient Sample between 2008 and 2012. For each racial/ethnic group, we calculated the AIH hospitalization rate per 100,000 population and per 100,000 all-cause hospitalizations, then calculated a risk ratio compared to the reference rate among whites. We used multivariable logistic regression models to assess for racial disparities and to identify predictors of in-hospital mortality during AIH hospitalizations.

RESULTS

The national rate of AIH hospitalization was 0.73 hospitalizations per 100,000 population. Blacks and Latinos were hospitalized for AIH at a rate 69% (P<0.001) and 20% higher (P<0.001) than whites, respectively. After controlling for age, gender, payer, residence, zip code income, region, and cirrhosis, black race was a statistically significant predictor for mortality during AIH hospitalizations (odds ratio (OR) 2.81, 95% confidence interval (CI) 1.43, 5.47).

CONCLUSIONS

Hospitalizations for AIH disproportionately affect black and Latino Americans. Black race is independently associated with higher odds of death during hospitalizations for AIH. This racial disparity may be related to biological, genetic, environmental, socioeconomic, and healthcare access and quality factors.

Review article: next-generation transformative advances in the pathogenesis and management of autoimmune hepatitis

BACKGROUND

Advances in autoimmune hepatitis that transform current concepts of pathogenesis and management can be anticipated as products of ongoing investigations driven by unmet clinical needs and an evolving biotechnology.

AIM

To describe the advances that are likely to become transformative in autoimmune hepatitis, based on the direction of current investigations.

METHODS

Pertinent abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and a secondary bibliography was developed. The discovery process was repeated, and a tertiary bibliography was identified. The number of abstracts reviewed was 2830, and the number of full-length articles reviewed exceeded 150.

RESULTS

Risk-laden allelic variants outside the major histocompatibility complex (rs3184504, r36000782) are being identified by genome-wide association studies, and their gene products are potential therapeutic targets. Epigenetic changes associated with environmental cues can enhance the transcriptional activity of genes, and chromatin re-structuring and antagonists of noncoding molecules of ribonucleic acid are feasible interventions. The intestinal microbiome is a discovery field for microbial products and activated immune cells that may translocate to the periphery and respond to manipulation. Epidemiological studies and controlled interview-based surveys may implicate environmental and xenobiotic factors that warrant evidence-based changes in lifestyle, and site-directed molecular and cellular interventions promise to change the paradigm of treatment from one of blanket immunosuppression.

CONCLUSIONS

Advances in genetics, epigenetics, pathophysiology, epidemiology, and site-directed molecular and cellular interventions constitute the next generation of transformative advances in autoimmune hepatitis.

Global Disparities and Their Implications in the Occurrence and Outcome of Autoimmune Hepatitis

Autoimmune hepatitis has a variable occurrence, clinical phenotype, and outcome, and the factors contributing to this variability are uncertain. The goals of this review are to examine the global disparities in the occurrence and outcome of autoimmune hepatitis, suggest bases for these disparities, and encourage investigations that extend beyond single-center experiences. Disparities in the incidence and prevalence of autoimmune hepatitis in different age groups, genders, ethnicities, and geographical regions suggest that factors other than genetic predisposition are involved. Age- and gender-related antigen exposures from the external (infections, toxins, and medications) and internal (intestinal microbiome) environment may affect the incidence of the disease, and the timeliness and nature of treatment may influence its prevalence. The increasing incidence of autoimmune hepatitis in Spain, Denmark, and the Netherlands suggests that a new etiological trigger has been introduced or that the susceptible population has changed. Variations in mortality between Western and Asian-Pacific countries may result from differences in disease detection or management, and variations in gender predilection, peak age of onset, frequency of concurrent immune diseases, and serological profile may reflect gender-biased and age-related antigen exposures and genetic predispositions. Global collaborations, population-based epidemiological studies that identify case clustering, and controlled interview-based surveys are mechanisms by which to understand these disparities and improve management. In conclusion, autoimmune hepatitis has a rising incidence in some countries and variable occurrence, phenotype, and outcome between countries and subgroups within countries. These disparities suggest that unrecognized population-based environmental, infectious, or socioeconomic factors are affecting its character.

Liver immunology: How to reconcile tolerance with autoimmunity

There are several examples of liver tolerance: the relative ease by which liver allografts are accepted and the exploitation of the hepatic microenvironment by the malarial parasite and hepatotrophic viruses are notable examples. The vasculature of the liver supports a unique population of antigen presenting cells specialised to maintain immunological tolerance despite continuous exposure to gut-derived antigens. Liver sinusoidal endothelial cells and Kupffer cells appear to be key to the maintenance of immune tolerance, by promoting T cell anergy or deletion and the generation of regulatory cell subsets. Despite this, there are three liver diseases with likely autoimmune involvement: primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune hepatitis. How can we reconcile this with the inherent tolerogenicity of the liver? Genetic studies have uncovered several associations with genes involved in the activation of the innate and adaptive immune systems. There is also evidence pointing to pathogenic and xenobiotic triggers of autoimmune liver disease. Coupled to this, impaired immunoregulatory mechanisms potentially play a permissive role, allowing the autoimmune response to proceed.

Factoring the intestinal microbiome into the pathogenesis of autoimmune hepatitis

The intestinal microbiome is a reservoir of microbial antigens and activated immune cells. The aims of this review were to describe the role of the intestinal microbiome in generating innate and adaptive immune responses, indicate how these responses contribute to the development of systemic immune-mediated diseases, and encourage investigations that improve the understanding and management of autoimmune hepatitis. Alterations in the composition of the intestinal microflora (dysbiosis) can disrupt intestinal and systemic immune tolerances for commensal bacteria. Toll-like receptors within the intestine can recognize microbe-associated molecular patterns and shape subsets of T helper lymphocytes that may cross-react with host antigens (molecular mimicry). Activated gut-derived lymphocytes can migrate to lymph nodes, and gut-derived microbial antigens can translocate to extra-intestinal sites. Inflammasomes can form within hepatocytes and hepatic stellate cells, and they can drive the pro-inflammatory, immune-mediated, and fibrotic responses. Diet, designer probiotics, vitamin supplements, re-colonization methods, antibiotics, drugs that decrease intestinal permeability, and molecular interventions that block signaling pathways may emerge as adjunctive regimens that complement conventional immunosuppressive management. In conclusion, investigations of the intestinal microbiome are warranted in autoimmune hepatitis and promise to clarify pathogenic mechanisms and suggest alternative management strategies.

Cutting edge issues in autoimmune hepatitis

Autoimmune hepatitis (AIH) is a severe liver disease affecting all age groups worldwide. Novel basic and clinical aspects of AIH, addressed at a Monothematic Conference in London in September 2015, are highlighted in this review. The diagnosis of AIH relies upon detection of characteristic autoantibodies, hypergammaglobulinemia, and interface hepatitis on liver histology. The International Autoimmune Hepatitis Group (IAIHG) has devised diagnostic scoring systems to help in comparative studies and clinical practice. AIH arises in a genetically predisposed host, when yet unknown triggers - such an encounter with a pathogen - lead to a T cell-mediated immune response targeting liver autoantigens. This immune response is inadequately controlled because regulatory mechanisms are impaired. The mainstay of treatment for AIH is immunosuppression, which should be instituted as soon as the diagnosis is made. Standard treatment regimens include relatively high doses of predniso(lo)ne, which are tapered gradually as azathioprine is introduced. Recent guidelines have described newer treatment regimens and have tightened the goal of therapy to complete normalization of biochemical, serological and histological parameters. Mycophenolate mofetil, calcineurin inhibitors, mTOR inhibitors and biological agents are potential salvage therapies, but should be reserved for selected non-responsive patients and administered only in experienced centers. Liver transplantation is a life-saving option for those patients who progress to end-stage liver disease. Further dissection of cellular and molecular pathways involved in AIH pathogenesis is likely to lead to the discovery of novel, tailored and better tolerated therapies.

Incidence and prevalence of autoimmune hepatitis in the Ueda area, Japan

AIM

Although autoimmune hepatitis (AIH) is considered to be rare in Japan, precise data on the incidence and prevalence of this disease are scarce due to the lack of a nationwide registry. We therefore conducted a study of these factors over a secondary medical care area.

METHODS

We retrospectively investigated the medical records of AIH patients seen during 2004-2009 and prospectively recruited subjects from 2010 to 2014 at our hospital. We surveyed via written questionnaires to all family doctors and hospitals in our secondary medical care area of Ueda, with a population 187 205 individuals over 14 years of age. We also surveyed several core liver disease hospitals in the areas neighboring Ueda.

RESULTS

Forty-eight patients with AIH were diagnosed between 2004 and 2014. AIH with histological features of acute hepatitis was increased. The average annual incidence of AIH in the area was 2.23 (age-standardized to the Japanese population). Forty-eight patients (37 patients diagnosed between 2004 and 2014, and 11 patients before 2003) were followed to the study end-point. The prevalence was 23.4 (age-standardized to the Japanese population) on 31 December 2014. After age-standardization to the World Health Organization world standard population, the incidence and prevalence of AIH decreased to 1.52 and 15.0, respectively, likely due to the high proportion of elderly patients in Japan.

CONCLUSION

The incidence and prevalence of AIH in Japan may be higher than previously believed due to increased awareness among family doctors, and a rise in the diagnosis of mild or atypical AIH.

Autoimmune hepatitis and long-term disease course in children in Turkey, a single-center experience

INTRODUCTION

The aim of this study is to determine clinic and laboratory features, treatment protocols, treatment responses, and long term follow-up of children with autoimmune hepatitis (AIH) in a region of Turkey followed at Ege University.

MATERIALS AND METHODS

The records of 47 children with AIH between 1998 and 2012 were retrospectively analyzed for clinical profiles, treatment response, relapse rate, and long-term side effects.

RESULTS

The median age of the children was 10±4.1 years (55.3% females). A total of 29 patients presented with chronic hepatitis (61.7%). According to the autoantibody profiles, 40 (85.1%) and seven (14.9%) cases were classified as type 1 and type 2, respectively. Presentation with acute hepatitis and chronic hepatitis was significantly higher in type 1 disease. Laboratory findings at presentation was found similar among races as well as AIH types (P>0.05). The prednisolone was used for remission induction in 37 patients; 86.4% (n: 32) achieved a complete response, 2.7% (n: 1) achieved a partial response, and four patients (10.8%) showed no response. Maintenance was attained by low-dose steroid plus thiopurine and relapse in steroid responders (n: 32) was 9.4% (n: 3) at 8, 12, and 48 months. A total of 36% (n: 24) had neither acute nor chronic treatment side effects. Bone marrow suppression was observed in five patients and hyperglycemia was observed in one patient (10.6 and 2.1%), respectively.

CONCLUSION

AIH type 1 prevails in children in a region of Turkey during the second decade of life. Low-dose corticosteroids combined with azathioprine are found.

National incidence of autoimmune liver diseases and its relationship with the human development index

OBJECTIVE

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH) and immunoglobulin G4 related cholangitis represent the major autoimmune liver diseases (AILD). However, the relationship between AILD incidence and socioeconomic development levels is yet to be explored.

RESULTS

A total of 43 studies were included. There was a positive but not significant correlation between the PBC incidence and HDI on a global level (r=0.348, P=0.082). However, in Europe, a significantly positive correlation existed between the PBC incidence and HDI (r=0.455, P=0.044). No statistical correlation between PSC incidence and HDI was observed (r=0.116, P=0.706). The incidence of AIH revealed a positive correlation with the national HDI both globally (r=0.638, P=0.014) and in Europe (r=0.644, P=0.045). Moreover, the PBC incidence demonstrated a positive correlation with the health index (r=0.422, P=0.036), but a negative correlation with the education index (r= -0.650, P<0.01). Moreover, the income index presented a positive correlation with both the PSC incidence (r=0.599, P=0.031) and the AIH incidence (r=0.649, P=0.012).

METHODS

PubMed was searched to identify relevant epidemiological studies on AILD. The human development index (HDI) was applied as an indicator for socioeconomic development. HDI data were obtained and calculated based on the 2014 Human Development Report. Pearson coefficient and linear regression analysis were conducted to estimate the correlation between incidence and HDI.

CONCLUSIONS

There is positive association between the national incidence of AILD and the socioeconomic status, as measured by HDI. In less-developed countries, the incidence of AILD, especially PBC and AIH, might be less common.

Auto immune hepatitis

To provide an update of the latest trends in epidemiology, clinical course, diagnostics, complications and treatment of auto immune hepatitis (AIH). A search of the MEDLINE database was performed using the search terms: “auto immune hepatitis”, “clinical presentation”, “symptoms”, “signs”, “diagnosis”, “auto antibodies”, “laboratory values”, “serology”, “histopathology”, “histology”, “genetics”, “HLA genes”, “non-HLA genes”, “environment”, “epidemiology”, “prevalence”, “incidence”, “demographics”, “complications”, “HCC”, “PBC”, “PSC”, “corticosteroid”, “therapy”, “treatment”, “alternative treatment”. English-language full-text articles and abstracts were considered. Articles included reviews, meta-analysis, prospective retrospective studies. No publication date restrictions were applied. AIH is an immune meditated progressive inflammatory liver disease that predominantly affects middle-aged females but may affect people of all ages. The clinical spectrum of AIH is wide, ranging from absent or mild symptoms to fulminant hepatic failure. The aetiology of AIH is still unknown, but is believed to occur as the consequence of an aberrant immune response towards an un-known trigger in a genetically susceptible host. In the absence of a gold standard, diagnosis is based on the combination of clinical, biochemical and histopathological criteria. Immunosuppressive treatment has been the cornerstone of treatment since the earliest description of the disease in 1950 by Waldenström. Such treatment is often successful at inducing remission and generally leads to normal life expectancy. Nevertheless, there remain significant areas of unmet aetiological a clinical needs including fundamental insight in disease pathogenesis, optimal therapy, duration of treatment and treatment alternatives in those patients unresponsive to standard treatment regimens.

The clinical phenotypes of autoimmune hepatitis: A comprehensive review

Autoimmune hepatitis (AIH) fulfills the generally accepted contemporary criteria of an autoimmune liver disease: the presence of autoantibodies and autoreactive T cells, a female gender bias, association with other autoimmune diseases, response to immunosuppressive therapy and strong associations with the major histocompatibility complex HLA loci. It occurs worldwide in both children and adults and is marked by both etiopathogenic and clinical heterogeneity, differing from the other putative autoimmune liver diseases, primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), albeit occasionally presenting with overlapping features of PBC or PSC. Although diagnostic criteria have been established and validated, there are still major issues to be clarified due to its variability, such as autoantibody-negative AIH, drug-induced AIH, AIH sharing features with PBC or PSC, and post-transplant de novo AIH. In view of the diverse presentations and courses, including classical chronic onset, acute and acute severe onset, cirrhosis and decompensated cirrhosis, individualized management of patients is indicated. Each patient should receive a personalized analysis of the benefits and side effect risks of drugs. Herein we describe a comprehensive review of the clinical phenotypes of AIH underscoring its clinical heterogeneity.

Incidence and Characteristics of Autoimmune Hepatitis

BACKGROUND AND OBJECTIVES

Autoimmune hepatitis (AIH) is a progressive inflammatory liver disease of unknown etiology, with limited population-based estimates of pediatric incidence. We reported the incidence of pediatric AIH in Canada and described its clinical characteristics.

METHODS

We conducted a retrospective cohort study of patients aged <18 years diagnosed with AIH between 2000-2009 at all pediatric centers in Canada.

RESULTS

A total of 159 children with AIH (60.3% female, 13.2% type 2 AIH) were identified. Annual incidence was 0.23 per 100000 children. Median age at presentation for type 1 was 12 years (interquartile range: 11-14) versus 10 years for type 2 (interquartile range: 4.5-13) (P = .03). Fatigue (58%), jaundice (54%), and abdominal pain (49%) were the most common presenting symptoms. Serum albumin (33 vs 38 g/L; P = .03) and platelet count (187 000 vs 249 000; P <.001) were significantly lower and the international normalized ratio (1.4 vs 1.2; P <.001) was higher in cirrhotic versus noncirrhotic patients. Initial treatment included corticosteroids (80%), azathioprine (32%), and/or cyclosporine (13%). Response to treatment at 1 year was complete in 90%, and partial in 3%. 3% of patients had no response, and 3% responded and later relapsed. Nine patients underwent liver transplantation, and 4 patients died at a mean follow-up of 4 years.

CONCLUSIONS

AIH is uncommon in children and adolescents in Canada. Type 1 AIH was diagnosed 5.5 times more frequently than type 2 AIH. Most patients respond well to conventional therapy, diminishing the need for liver transplantation.

Autoimmune hepatitis: East meets west

Autoimmune hepatitis (AIH) is an inflammatory liver disease with diverse clinical spectrum, which predominantly affects females. This review provides detailed comparisons of epidemiology, genetic predispositions, clinical features, risk factors of hepatocellular carcinoma, and mortality in AIH patients between eastern and western countries. AIH prevalence and incidence are lower in Asia-Pacific area than in Europe and America. European and American patients seem to have more severe disease, characterized with human leukocyte antigen-DR3 haplotype, younger age, more AIH-induced "cirrhosis" at diagnosis, higher elevated serum immunoglobulin G levels, and positive rate of antisoluble liver antigen/liver pancreatitis. The overall AIH diagnostic accuracy of revised original criteria and simplified scoring system are similar in European/American populations and Asian. Cirrhosis at presentation and non-response to immunosuppressive therapy within 1 year are the most important predictors for poor prognosis of AIH patients.

Update on Autoimmune Hepatitis

Autoimmune hepatitis (AIH), a liver disorder affecting both children and adults, is characterized by inflammatory liver histology, elevated transaminase levels, circulating nonorganspecific autoantibodies, and increased levels of immunoglobulin G, in the absence of a known etiology. Two types of AIH are recognized according to seropositivity: smooth muscle antibody and/or antinuclear antibody define AIH type 1 and antibodies to liver-kidney microsome type 1 and/or liver cytosol type 1 define AIH type 2. AIH type 1 affects both adults and children, while AIH type 2 is mainly a paediatric disease, though it does occasionally affects young adults. AIH should be considered during the diagnostic workup of any patient with increased liver enzyme levels. AIH is exquisitely responsive to immunosuppressive treatment with prednisolone with or without azathioprine, with symptom free long-term survival for the majority of patients. For those who do not respond to standard treatment, or who are difficult-to-treat, mycophenolate mofetil and, in the absence of a response, calcineurin inhibitors should be tried in addition to steroids. The pathogenesis of AIH is not fully understood, although there is mounting evidence that genetic susceptibility, molecular mimicry and impaired immunoregulatory networks contribute to the initiation and perpetuation of the autoimmune attack. Liver damage is thought to be mediated primarily by CD4 T-cells, although recent studies support the involvement of diverse populations, including Th17 cells. A deeper understanding of the pathogenesis of AIH is likely to contribute to the development of novel treatments, such as the adoptive transfer of autologous expanded antigenspecific regulatory T-cells, which ultimately aim at restoring tolerance to liver-derived antigens.

Epidemiology and clinical characteristics of autoimmune hepatitis in the Netherlands

BACKGROUND AND AIMS

Epidemiological data on autoimmune hepatitis (AIH) are scarce. In this study, we determined the clinical and epidemiological characteristics of AIH patients in the Netherlands (16.7 million inhabitants).

METHODS

Clinical characteristics were collected from 1313 AIH patients (78% females) from 31 centers, including all eight academic centers in the Netherlands. Additional data on ethnicity, family history and symptoms were obtained by the use of a questionnaire.

RESULTS

The prevalence of AIH was 18.3 (95% confidential interval [CI]: 17.3-19.4) per 100,000 with an annual incidence of 1.1 (95% CI: 0.5-2) in adults. An incidence peak was found in middle-aged women. At diagnosis, 56% of patients had fibrosis and 12% cirrhosis in liver biopsy. Overall, 1% of patients developed HCC and 3% of patients underwent liver transplantation. Overlap with primary biliary cirrhosis and primary sclerosing cholangitis was found in 9% and 6%, respectively. The clinical course did not differ between Caucasian and non-Caucasian patients. Other autoimmune diseases were found in 26% of patients. Half of the patients reported persistent AIH-related symptoms despite treatment with a median treatment period of 8 years (range 1-44 years). Familial occurrence was reported in three cases.

CONCLUSION

This is the largest epidemiological study of AIH in a geographically defined region and demonstrates that the prevalence of AIH in the Netherlands is uncommon. Although familial occurrence of AIH is extremely rare, our twin data may point towards a genetic predisposition. The high percentage of patients with cirrhosis or fibrosis at diagnosis urges the need of more awareness for AIH.

Juvenile autoimmune hepatitis: Spectrum of the disease

Juvenile autoimmune hepatitis (JAIH) is a progressive inflammatory liver disease, affecting mainly young girls, from infancy to late adolescence, characterized by active liver damage, as shown by high serum activity of aminotransferases, by elevated immunoglobulin G levels, high titers of serum non organ-specific and organ-specific autoantibodies, and by interface hepatitis on liver biopsy. It is a multifactorial disease of unknown etiology in which environmental factors act as a trigger in genetically predisposed individuals. Two types of JAIH are identified according to the autoantibody panel detected at diagnosis: AIH-1, characterized by the presence of anti-smooth muscle antibody and/or antinuclear antibody and AIH-2, by anti-liver-kidney microsomal antibody type 1 and/or by the presence of anti-liver cytosol type 1 antibody. Epidemiological distribution, genetic markers, clinical presentation and pattern of serum cytokines differentiate the two types of AIH suggesting possible pathogenetic mechanisms. The most effective therapy for AIH is pharmacological suppression of the immune response. Treatment should be started as soon as the diagnosis is made to avoid severe liver damage and progression of fibrosis. The aim of this review is to outline the most significant and peculiar features of JAIH, based largely on our own personal database and on a review of current literature.

Autoimmune hepatitis in Denmark: incidence, prevalence, prognosis, and causes of death. A nationwide registry-based cohort study

BACKGROUND & AIMS

Population-based studies of the clinical course of autoimmune hepatitis are scarce. We conducted a nationwide study of incidence, prevalence, prognosis, and causes of death of autoimmune hepatitis in Denmark.

METHODS

From nationwide healthcare registries we identified all Danish citizens diagnosed with autoimmune hepatitis in 1994-2012 and their liver biopsy data. We followed patients through January 2013 and examined age-standardized incidence and prevalence, mortality, prognostic factors, risk of hepatocellular carcinoma, and causes of death. We used Cox regression to compare patients' mortality relative to a gender- and age-matched general population sample.

RESULTS

We included 1721 autoimmune hepatitis patients. The incidence rate was 1.68 (95% confidence interval 1.60 to 1.76) per 100,000 population per year, and it doubled during the study period. Of the 1318 patients who were biopsied at diagnosis, 28.3% had cirrhosis. The 10-year cumulative risk of hepatocellular carcinoma was 0.7% (95% confidence interval 0.3 to 1.5). Male gender and cirrhosis were associated with high mortality and development of hepatocellular carcinoma. In the first year after diagnosis, patients with autoimmune hepatitis had six-fold higher mortality than the general population; later, their mortality remained two-fold higher. Their 10-year cumulative mortality was 26.4% (95% confidence interval 23.7 to 29.1). 38.6% of deaths were liver-related including 3.6% from hepatocellular carcinoma.

CONCLUSIONS

This nationwide population-based study of autoimmune hepatitis showed that the incidence increased during 1994-2012, and that the disease remains associated with a high mortality, particularly in the first year after diagnosis. Male gender and cirrhosis were adverse prognostic factors.

Autoimmune hepatitis in southern Israel: a 15-year multicenter study

OBJECTIVE

In this study we aimed to assess the incidence, prevalence and clinical outcomes of patients with autoimmune hepatitis (AIH) in southern Israel.

METHODS

Case-finding methods and population-based administrative data were used to evaluate the epidemiology and prognostic factors of AIH from 1995 to 2010.

RESULTS

During the study period, the average annual prevalence and incidence of AIH in southern Israel were 11.0/100000 and 0.67/100000, respectively. We identified 100 AIH cases with a mean age of 47.9 years, including 95 women and five men. Type 1 AIH was found in 77 cases, and liver fibrosis and cirrhosis were found in 73.4% and 22.3% of all patients who underwent liver biopsy. In all, 98 patients were treated with a combination of steroids and azathioprine or steroids alone (prednisone and azathioprine in 71, budesonide and azathioprine in 11, prednisone or budesonide alone in six and ten, respectively). Complete remission was recorded in 56 patients, whereas partial response or failure of treatment was noted in 42 patients. In multivariate analysis the independent predictors of remission were the degree of liver fibrosis (mild vs bridging fibrosis (F3) and cirrhosis [F4]) (P=0.003) and level of albumin (P=0.031). The estimated 1-year and 10-year survival for AIH were 96.5% and 89.7%, respectively.

CONCLUSIONS

The prevalence of AIH in Israel is quite similar to that of other European Caucasian populations, with a relatively long-term good prognosis, despite a low rate of response to immunosuppressive therapy.

Role of international criteria in the diagnosis of autoimmune hepatitis

AIM: To study the clinical and laboratory characteristics of autoimmune hepatitis (AIH), and compare them with International Autoimmune Hepatitis Group (IAHG) criteria.

METHODS: Sixty consecutive patients with AIH attended the University Clinic at Tabriz University of Medical Sciences, Iran for a 12 mo period and were assessed in a case series study. Serological and biochemical evaluations were carried out in all patients. Autoantibodies, such as antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA), anti-liver-kidney microsomal antibody (ALKM-1) type 1, and perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) were evaluated in these patients. A liver biopsy was performed after diagnosis of the disease. Patients were evaluated in terms of their signs and symptoms, and laboratory results and the degree to which they corresponded with the diagnostic criteria of IAHG. In this study, both a comprehensive diagnostic scoring system and a simplified diagnostic scoring system were employed for AIH.

RESULTS: Sixty patients, 20 male, 40 female, mean age 39.45 ± 17.50 years, participated in the study. Treatment began immediately after enrolment into the study. The percent distribution of the study population into definite and probable did not change after the treatment. The most common symptoms in descending order were fatigue (100%), icter (66.7%), abdominal discomfort (33.3%), abdominal distension (28.3%), dark urine (23.3%), edema (23.3%), hematemesis (20.0%), pruritus (20.0%), melena (11.7%) and pale stool (10.0%). At the physical examination, splenomegaly, ascites, hepatomegaly, epigastric tenderness and an abdominal mass were found in 50.0%, 16.7%, 13.3%, 5.0% and 3.3% of patients, respectively. Hypergammaglobulinemia was detected in 95.0% of cases. ALKM-1, P-ANCA, ANA and ASMA were positive in 71.4%, 66.7%, 42.4% and 19.4% of cases, respectively. Portal hypertensive gastropathy (45.0%), esophageal varices (41.7%) and cirrhosis (40.0%) were the most prevalent complications of AIH, and there was no evidence of primary sclerosing cholangitis, ulcerative colitis and overlap syndrome in these patients. According to IAHG criteria, 80.0% of cases had a definite diagnosis, 15.0% had a probable diagnosis and 5.0% had no AIH. The percent distribution of the study population into definite, probable and no AIH did not change after using the simplified diagnostic scoring system for AIH.

CONCLUSION: This research showed that the majority of cases in our study were appropriately diagnosed according to the IAHG criteria and simplified scoring system. Thus, these criteria are very useful.

Cutting edge issues in autoimmune hepatitis

Autoimmune hepatitis is an inflammatory liver disease affecting mainly females and characterised histologically by interface hepatitis, biochemically by elevated transaminase levels and serologically by circulating autoantibodies and increased levels of immunoglobulin G. Autoimmune hepatitis responds to immunosuppressive treatment, which should be instituted as soon as diagnosis is made. Seropositivity for smooth muscle and/or antinuclear antibody defines type 1 autoimmune hepatitis, while positivity for liver kidney microsomal type 1 antibody defines type 2 autoimmune hepatitis. The aetiology of autoimmune hepatitis is unknown, though both genetic and environmental factors are involved in its expression. The major mechanism of liver damage involves immune reactions against host liver antigens that are not adequately controlled by defective regulatory T cells. Current research aiming at potentiating regulatory T cell function in vitro to reconstitute tolerance in vivo has given promising results.

Epidemiology and treatment of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory disease of the liver that occurs worldwide with a low and probably underestimated prevalence. Although it typically affects young and middle-aged women, it can occur in both sexes and across all age groups. AIH runs a fluctuating course, but can present as severe and even fulminant hepatic failure or at a stage of advanced fibrosis or cirrhosis. Prognosis of severe AIH is poor if untreated. The pathogenesis is complex, combining environmental factors (external chemical or infectious triggers) and host genetic susceptibility. The diagnosis is based, after exclusion of other etiologies of chronic liver disease, on a combination of different elements, including the presence of elevated transaminases, elevated immunoglobulin G (IgG) levels, the presence and pattern of typical autoantibodies, and a liver biopsy showing interface hepatitis and other characteristic features. No single test can be used to make the diagnosis. Response to treatment can also help to establish the diagnosis. Simplified criteria can be used to make a bedside diagnosis with relatively high accuracy. Treatment consists of corticosteroids or other immunosuppressive regimens according to the severity of the disease, the response to the treatment, and the tolerance to therapy, with liver transplantation as an ultimate remedy in treatment-resistant cases with liver decompensation.

Autoimmune hepatitis

Autoimmune hepatitis (AIH) is an inflammatory liver disease that mainly affects females. It is characterized histologically by interface hepatitis, biochemically by increased aspartate and alanine aminotransferase levels, and serologically by the presence of autoantibodies and increased levels of immunoglobulin G. AIH affects both adults and children, and is particularly aggressive in the latter group. It is a relatively rare but devastating disease, which progresses rapidly unless immunosuppressive treatment is started promptly. With appropriate treatment 80% of patients achieve remission and long-term survival. Those patients who progress to end-stage liver disease because they are unresponsive or nonadherent to treatment, and those with fulminant liver failure (encephalopathy grade II-IV) at diagnosis, require liver transplantation. Seropositivity for smooth muscle and/or antinuclear antibodies defines type 1 AIH, while positivity for liver kidney microsomal type 1 antibodies defines type 2 AIH. The primary cause of AIH is unknown; however, considerable knowledge about the mechanisms of liver damage involved has been gathered over the past 30 years, which is likely to provide the basis for specific modes of treatment and a possible cure.

Population-based epidemiology study of autoimmune hepatitis: a disease of older women?

BACKGROUND AND AIM

The etiology of autoimmune hepatitis (AIH) is unknown, and limited epidemiological data are available. Our aim was to perform a population based epidemiological study of AIH in Canterbury, New Zealand.

METHODS

To calculate point prevalence, all adult and pediatric outpatient clinics and hospital discharge summaries were searched to identify all cases of AIH in the Canterbury region. Incident cases were recruited prospectively in 2008. Demographic and clinical data were extracted from case notes. Both the original revised AIH criteria and the simplified criteria were applied and cases were included in the study if they had definite or probable AIH.

RESULTS

When the original revised criteria were used, 138 cases (123 definite and 14 probable AIH), were identified. Prospective incidence in 2008 was 2.0/100,000 (95% confidence interval [CI] 0.8-3.3/100,000). Point prevalence on 31 December 2008 was 24.5/100,000 (95% CI 20.1-28.9). Age-standardized (World Health Organization standard population) incidence and prevalence were 1.7 and 18.9 per 100,000, respectively. Gender-specific prevalence confirmed a female predominance, while ethnicity-specific prevalence showed higher prevalence in Caucasians. 72% of cases presented after 40 years of age and the peak age of presentation was in the sixth decade of life.

CONCLUSIONS

This is the first and largest population-based epidemiology study of AIH in a geographically defined region using standardized inclusion criteria. The observed incidence and prevalence rates are among the highest reported. The present study confirms that AIH presents predominantly in older women, with a peak in the sixth decade, contrary to the classical description of the disease.

Recent insights in the epidemiology of autoimmune diseases: improved prevalence estimates and understanding of clustering of diseases

Previous studies have estimated a prevalence of a broad grouping of autoimmune diseases of 3.2%, based on literature review of studies published between 1965 and 1995, and 5.3%, based on national hospitalization registry data in Denmark. We examine more recent studies pertaining to the prevalence of 29 autoimmune diseases, and use these data to correct for the underascertainment of some diseases in the hospitalization registry data. This analysis results in an estimated prevalence of 7.6-9.4%, depending on the size of the correction factor used. The rates for most diseases for which data are available from many geographic regions span overlapping ranges. We also review studies of the co-occurrence of diseases within individuals and within families, focusing on specific pairs of diseases to better distinguish patterns that may result in insights pertaining to shared etiological pathways. Overall, data support a tendency for autoimmune diseases to co-occur at greater than expected rates within proband patients and their families, but this does not appear to be a uniform phenomenon across all diseases. Multiple sclerosis and rheumatoid arthritis is one disease pair that appears to have a decreased chance of coexistence.

Autoimmune hepatitis

Autoimmune hepatitis (AIH) is an inflammatory liver disease affecting mainly females and characterised histologically by interface hepatitis, biochemically by elevated transaminase levels and serologically by the presence of autoantibodies and increased levels of immunoglobulin G. AIH responds to immunosuppressive treatment, which should be instituted as soon as diagnosis is made. Seropositivity for smooth muscle and/or anti-nuclear antibody defines type 1 AIH, while positivity for liver kidney microsomal type 1 antibody defines type 2 AIH. The aetiology of AIH is unknown, though both genetic and environmental factors are involved in its expression. Immune reactions against host liver antigens are believed to be the major mechanism of liver damage.