Historical reflections on autoimmune hepatitis

Histopathology of Autoimmune Hepatitis: An Update

Autoimmune hepatitis (AIH) is a rare immune-mediated chronic liver disease that is diagnosed based on a combination of biochemical, immunologic, and histologic features and the exclusion of other causes of liver disease. According to the new consensus criteria of the International Autoimmune Hepatitis Pathology Group (IAIHPG), the likely histologic features include a chronic hepatitis pattern of injury with a lymphoplasmacytic portal infiltrate, interface activity, and portal-based fibrosis. More than mild lobular hepatitis with any of the above features can also be diagnosed as likely AIH in the absence of features of another liver disease. Centrilobular injury with prominent hepatocellular necrosis and mononuclear inflammation may represent an acute-onset disease and indicate possible AIH in the absence of concurrent liver disease. Kupffer cell hyaline bodies and portal lymphocyte apoptosis are significantly associated with AIH, whereas emperipolesis and hepatocellular rosette formation are nonspecific features indicative of disease severity. Liver histology is an integral part of the clinical diagnostic scoring system and is required to confirm or support AIH diagnosis. Substitution of the histologic component of the simplified AIH scoring system with the consensus IAIHPG criteria has been proposed to optimize clinical diagnosis. This review explores the significant role of histopathology in AIH by analyzing its main features and current histologic diagnostic criteria, different AIH presentations, differential diagnosis, assessment of concurrent liver disease, and identification of AIH variants with primary cholangiopathy.

Autoimmune Hepatitis: From Evolution to Current Status-A Pathologist's Perspective

Autoimmune hepatitis (AIH) is a chronic, relapsing and remitting, immune-mediated liver disease that progresses to cirrhosis if left untreated. A significant number of patients may present with acute hepatitis or acute liver failure, which are often misdiagnosed as toxic liver injury. AIH shows a preponderance in young women but may be seen in children and the elderly. Diagnosis requires the integration of clinical, biochemical, and serologic parameters, along with supportive liver histology and exclusion of other causes of liver disease. Liver biopsy is a prerequisite for diagnosis of AIH, to assess severity and stage of disease, exclude other entities, and recognize any concurrent morbidities. No single biomarker or histologic feature is pathognomonic for AIH. The diagnostic and histologic criteria have undergone several modifications since the original scoring system was proposed by the International Autoimmune Hepatitis Group (IAIHG) in 1993. Recently, the IAIHG has proposed consensus recommendations for histologic criteria, relevant for both acute and chronic AIH. This review article will describe the evolving diagnostic criteria for AIH, with their limitations and utility, and with an emphasis on the role of liver histology in the diagnosis and management of AIH.

Estimating autoimmune hepatitis in patients with hepatic dysfunction

Autoimmune Hepatitis (AIH) is a chronic inflammatory disease of the liver of unknown aetiology characterized by polyclonal hypergammaglobulinemia and circulating autoantibodies. Objective of the study is to find out the prevalence of autoimmune hepatitis and its causative autoantibody (Anti-nuclear, anti-smooth muscle, anti-liver kidney microsomes-1) following comprehensive diagnostic criteria given by International Autoimmune Hepatitis Group.

MATERIAL AND METHODS

250 patients with raised aminotransferase but, negative for the commonest three clinical conditions viz, viral hepatitis, drug induced liver injury and alcohol induced liver injury were suspected to be a case of autoimmune hepatitis. Recent IAIHG criteria was followed in making diagnosis of autoimmune hepatitis. We did the investigation for viral hepatitis (acute/chronic), drug induced liver injury and alcohol induced liver injury and then measured serum IgG. Indirect Immunofluorescence (IIF) was done for Anti-nuclear antibody and was also done for anti-smooth muscle antibody and anti-liver kidney microsomes-1 antibody simultaneously.

RESULT

As per IAIHG criteria, out of 250 patients, Ig "G" was elevated in 88 patients with significant titres for Anti-nuclear antibody (50 patients), anti-smooth muscle antibody (65 patients), anti-liver kidney microsomes-1 antibody (7 patients) and Anti-mitochondrial antibody (18 patients) were found. As per International Autoimmune Hepatitis Group Comprehensive scoring system, probable diagnosis was made in 83 patients (33.2%) and 12 were confirmed for autoimmune hepatitis (4.8%).

CONCLUSION

Female preponderance was observed and type 1 Autoimmune Hepatitis was most common whereas type 2 Autoimmune Hepatitis was found in few cases. Most patients had anti-smooth muscle antibody and anti-nuclear antibody positivity indicating the type, but no significant difference was seen in clinical symptoms or biochemical parameters between the different types. 162 patients couldn't be evaluated for autoimmune hepatitis because of serum IgG cut-off criteria >1500 ​mg/l.

Advances in Understanding and Managing Autoimmune Hepatitis: A Narrative Review

Autoimmune hepatitis (AIH) is a chronic liver disease characterized by immune-mediated destruction of hepatocytes, leading to inflammation and fibrosis. In recent years, significant advances have been made in understanding the pathogenesis, epidemiology, diagnosis, and treatment of AIH. This comprehensive narrative review aims to provide an up-to-date overview of these advances. The review begins by outlining the historical background of AIH, dating back to its initial recognition in the 1940s, and highlights the evolution of diagnostic criteria and classification based on autoantibody profiles. The epidemiology of AIH is explored, discussing its varying prevalence across different regions and the role of genetic predisposition, viral infections, and drug exposure as risk factors. Furthermore, the review delves into the pathogenesis of AIH, focusing on the dysregulated immune response, involvement of T cells, and potential contribution of the gut microbiome. Clinical presentation, diagnostic criteria, and liver biopsy as crucial tools for diagnosis are also discussed. Regarding management, the review provides an in-depth analysis of the standard first-line treatments involving glucocorticoids and azathioprine, as well as alternative therapies for non-responsive cases. Additionally, emerging second and third-line treatment options are examined. In conclusion, this narrative review highlights the complexity of AIH and underscores the importance of early diagnosis and individualized treatment approaches to improve patient outcomes. Further research and clinical trials are needed to optimize AIH management and ensure a better long-term prognosis for affected individuals.

Pharmacokinetic/Pharmacodynamic Assessment of Selective Phosphodiesterase Inhibitors in a Mouse Model of Autoimmune Hepatitis

Autoimmune hepatitis (AIH) is a life-threatening disorder currently treated with nonspecific immunosuppressive drugs. It is postulated that phosphodiesterase (PDE) inhibitors, as agents exerting anti-inflammatory and immunomodulatory activities, may constitute a possible treatment of autoimmune disorders. This study develops a pharmacokinetic/pharmacodynamic (PK/PD) model to assess the effects of PDE-selective inhibitors, namely, cilostazol (PDE3), rolipram (PDE4), and BRL-50481 (PDE7), in a mouse model of AIH. The pharmacokinetics of the PDE inhibitors (PDEi) were assessed in male BALB/c mice after intraperitoneal administration. In pharmacodynamic studies, mice received PDEi and AIH was induced in these animals by intravenous injection of concanavalin A (ConA). Serum drug concentrations, tumor necrosis factor α (TNFα), interleukin 17 (IL-17), and aminotransferase activities were quantified. The PK/PD analysis was performed using ADAPT5 software. The PK/PD model assumes inhibition of cAMP hydrolysis in T cells by PDEi, ConA-triggered formation of TNFα and IL-17, suppression of TNFα and IL-17 production by cAMP, and stimulatory effects of TNFα and IL-17 on the hepatic release of aminotransferases. Selective blockage of PDE4 leads to the highest inhibition of cAMP degradation in T cells and amelioration of disease outcomes. However, inhibition of both PDE3 and PDE7 also contribute to this effect. The proposed PK/PD model may be used to assess and predict the activities of novel PDEi and their combinations in ConA-induced hepatitis. A balanced suppression of different types of PDE appears to be a promising treatment option for AIH; however, this hypothesis warrants testing in humans based on translation of the PK/PD model into clinical settings. SIGNIFICANCE STATEMENT: A novel PK/PD model of PDE inhibitor effects in mice with ConA-induced autoimmune hepatitis was developed involving a mechanistic component describing changes in cAMP concentrations in mouse T cells. According to model predictions, inhibition of PDE4 in T cells causes the highest cAMP elevation in T cells, but suppression of PDE3 and PDE7 also contribute to this effect. A balanced inhibition of PDE3, PDE4, and PDE7 appears to be a promising treatment strategy for AIH.

Autoimmmune hepatitis

Autoimmune hepatitis (AIH) is a T-cell mediated, inflammatory liver disease affecting all ages and characterized by female preponderance, elevated serum transaminase and immunoglobulin G levels, positive circulating autoantibodies, and presence of interface hepatitis at liver histology. AIH type 1, affecting both adults and children, is defined by positive anti-nuclear and/or anti-smooth muscle antibodies, while type 2 AIH, affecting mostly children, is defined by positive anti-liver-kidney microsomal type 1 and/or anti-liver cytosol type 1 antibody. While the autoantigens of type 2 AIH are well defined, being the cytochrome P4502D6 (CYP2D6) and the formiminotransferase cyclodeaminase (FTCD), in type 1 AIH they remain to be identified. AIH-1 predisposition is conferred by possession of the MHC class II HLA DRB1*03 at all ages, while DRB1*04 predisposes to late onset disease; AIH-2 is associated with possession of DRB1*07 and DRB1*03. The majority of patients responds well to standard immunosuppressive treatment, based on steroid and azathioprine; second- and third-line drugs should be considered in case of intolerance or insufficient response. This review offers a comprehensive overview of pathophysiological and clinical aspects of AIH.

The association between juvenile autoimmune hepatitis and HLA-DRB1 alleles: Iraqi tertiary center experience

Aim of the study

To highlight the impact of the human leukocyte antigen (HLA) allele on susceptibility and prevention of autoimmune hepatitis (AIH) in Iraqi children.

Material and methods

We conducted a prospective study from children attending the Gastroenterology and Hepatology Clinic of Children’s Welfare Teaching Hospital over five years from the first of September 2015 to the thirty-first of August 2020. It included 19 patients with AIH; their age (at time of diagnosis) ranged between 3 and 16 years, with a female predominance of 78.9%. The diagnosis was made by clinical, serological, and histological features. In addition, 20 age- and sex-matched unrelated subjects of the same ethnic background were selected randomly from healthy individuals undergoing checkup as controls.

Results

19 patients diagnosed with AIH were included in this study, and 20 age- and sex-matched healthy controls, with a female predominance of 78.9%. The commonest autoantibodies found were smooth muscle antibody (SMA) in 13 (68.4%), antinuclear antibody (ANA) in 11 (57.9%). In AIH type 1, PCR showed higher frequencies among patients with HLA-DRB1*03, HLA-DRB1*04, HLA-DRB1*13 alleles in patients with AIH; moreover DRB1*11 and DRB1*15 were less frequent than in the control group. Frequency of HLA-DRB1*04 was 28% and HLA-DRB1*13 was 20% in AIH type 2 patients; HLA-DRB1*13 and HLA-DRB5 showed frequency of 25% for both and HLA-DRB4 frequency was 18.7%.

Conclusions

HLA-DRB1*13, DRB1*04, and DRB1*03 are susceptibility alleles for the development of AIH type 1, while HLA-DRB1*13, HLA-DRB4 and DRB5 are susceptibility alleles for the development of AIH type 2 in Iraqi children.

Synthesis and biological evaluation of (1,2,4)triazole[4,3-a]pyridine derivatives as potential therapeutic agents for concanavalin A-induced hepatitis

A series of (1,2,4)triazole[4,3-a]pyridine (TZP) derivatives have been designed and synthesized. Compound 8d was identified as having the most potent inhibitory activity on NO release in response to lipopolysaccharide (LPS) stimulation and inhibition of the migration induced by MCP-1 protein on RAW264.7 macrophages. Based on the screening data, an immunofluorescence assay and a real-time qPCR assay were conducted, indicating that compound 8d suppressed NF-κB p65 translocation and expression of inflammatory genes by concanavalin A (Con A)-induced RAW264.7 macrophages. More importantly, 8d also exhibited potent efficacy, alleviating Con A-induced hepatitis by downregulating the levels of plasma alanine transaminase (ALT), aspartate transaminase (AST) and inflammatory infiltration in a mouse autoimmune hepatitis (AIH) model. In addition, the flow cytometry (FCM) data showed that compound 8d inhibited the accumulation of MDSCs in the liver of Con A-induced mice. These findings raise the possibility that compound 8d might serve as a potential agent for the treatment of AIH.

Autoimmune hepatitis: Current and future therapeutic options

Autoimmune hepatitis (AIH) is a rare immune-mediated liver disease with few major advances in treatment options over the last several decades. Available options are effective in most patients albeit are imprecise in their mechanisms. Novel and more tolerable induction regimens and alternative options for management of patients intolerant or with suboptimal response to traditional therapies including in the post-transplant setting remain an important unmet need. This review aims to summarize recent data on pharmacological options and investigational drugs in development for patients with AIH. Standard therapy using prednisone with or without azathioprine remains the mainstay of therapy and is effective in most patients. Budesonide may be considered for induction in early disease and in those with mild fibrosis, but has not been approved for maintenance therapy. Mycophenolate mofetil (MMF) in combination with steroids might be an alternative first-line therapy, but results from a randomized trial are awaited. MMF as a second-line maintenance agent has moderate efficacy though more frequent adverse events in patients with cirrhosis may be seen. Tacrolimus may be an equally effective second-line option particularly in non-responders, but data remain limited. Management of recurrent AIH post-liver transplantation remains controversial with insufficient data to support long-term steroid use. Moving forward, expanding the scope of therapeutic options to include biologics including B-cell depleting agents may be a promising step. Recent insights in understanding the pathogenesis of AIH could serve as a basis for future therapies, including the elucidation of different immunoregulatory pathways and the potential role of the intestinal microbiome.

Autoimmune Hepatitis in the Asia-Pacific Area

Autoimmune hepatitis has been considered as a relatively rare immunological liver disease, especially in the Asia-Pacific area. Although the diagnosis criteria and immunosuppressive treatment regimens have been established, there are still some challenges. According to the different presentations, the personalized management of patients who suffer from this disease, including those with chronic or acute severe onset, the autoantibody-negative phenotype and cirrhosis are necessarily descriptive. Each subgroup of patients should receive an individualized therapy. Here, we review the recent studies of autoimmune hepatitis, mainly focusing on the epidemiology and genetics, personalized diagnostics, individualized treatment strategies, special subgroups and outcomes. Most of the research in the literature is based on Japanese and Chinese populations.

Diagnostic autoantibodies for autoimmune liver diseases

Autoimmune liver diseases are conditions of low prevalence that comprise the triad of autoimmune hepatitis, primary biliary cholangitis (cirrhosis) and primary sclerosing cholangitis and their poorly characterised overlapping syndromes. Diagnostic autoantibodies are associated with autoimmune hepatitis and primary biliary cholangitis but not with primary sclerosing cholangitis. Autoantibodies are useful disease markers that facilitate early diagnosis of autoimmune hepatitis and primary biliary cholangitis and allow for therapeutic intervention to prevent progression to liver cirrhosis and associated complications. Adult onset type 1 autoimmune hepatitis is associated with F-actin reactive smooth muscle autoantibody, antinuclear autoantibody in 60% of patients, and autoantibody to SLA/LP in 15–20%. Juvenile onset type 2 autoimmune hepatitis is associated with LKM-1 and LC-1 autoantibodies. Primary biliary cholangitis is associated with a mitochondria-associated autoantibody designated M2 in >90% of patients and with disease-specific antinuclear autoantibodies in 50% that bind to antigens in the nuclear core complex and in multiple nuclear dots. Autoantibodies to the nuclear core complex target gp210, nucleoporin p62 and nuclear lamin B receptor. Autoantibodies to multiple nuclear dots target Sp100 and PML antigens. Liver autoantibodies in asymptomatic patients with normal liver function may precede the subsequent development of overt autoimmune liver disease. For routine diagnostic immunology laboratories, initial screening for liver autoantibodies by immunofluorescence remains the method of choice with confirmation for reactivity with their target antigen by enzyme-linked immunosorbent assay (ELISA) or line blot when required.

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.

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.

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.

Fashioning the immunological self: the biological individuality of F. Macfarlane Burnet

During the 1940s and 1950s, the Australian microbiologist F. Macfarlane Burnet sought a biologically plausible explanation of antibody production. In this essay, we seek to recover the conceptual pathways that Burnet followed in his immunological theorizing. In so doing, we emphasize the influence of speculations on individuality, especially those of philosopher Alfred North Whitehead; the impact of cybernetics and information theory; and the contributions of clinical research into autoimmune disease that took place in Melbourne. We point to the influence of local experimental and intellectual currents on Burnet's work. Accordingly, this essay describes an arc distinct from most other tracings of Burnet's conceptual development, which focus on his early bacteriophage research, his fascination with the work of Julian Huxley and other biologists in the 1920s, and his interest in North Atlantic experimental investigations in the life sciences. No doubt these too were potent influences, but they seem insufficient to explain, for example, Burnet's sudden enthusiasm in the 1940s for immunological definitions of self and not-self. We want to demonstrate here how Burnet's deep involvement in philosophical biology - along with attention to local clinical research - provided him with additional theoretic tools and conceptual equipment, with which to explain immune function.

Autoimmune hepatitis: what must be said

Autoimmune hepatitis (AIH) was first studied under its earlier name of "chronic active hepatitis" (CAH) from the 1950s, coincident with a renaissance of interest in autoimmunity. The definition of autoimmune serum reactants in disease, including CAH, gave new insights into chronic hepatitis and liver cirrhosis, and led to refinements of Burnet's clonal selection theory of acquired immunity, 1957-59. Various discoveries including serological reactants in CAH prompted its designation in 1965 as autoimmune hepatitis, and treatment with immunosuppressive drug regimens transformed outcomes and survival. Serological observations further indicated that AIH could exist as either of two types, clinically similar but genetically different: Type 1 aligned more with the non-organ-specific multisystem diseases, and the infrequent Type 2 more with the organ-specific diseases. However, events in either type that could explain the onset of autoimmunity in the normally tolerogenic milieu of the liver have not been discerned. In the genetically predisposed individual, initiation may depend on non-specific death of hepatocytes after which fragments derived from disordered apoptosis acquire the capacity for ongoing auto-immunogenic stimulation. Insufficiency in numbers and function of Treg populations appears important in the promotion of this autoimmune process.

Complete spectrum of AMA-M2 positive liver disease in north India

PURPOSE

This study describes the clinical, histological, and genetic profile of AMA-M2 positive liver disease in north India.

METHODS

Over 13.5 years, 11,221 patients suspected of AiLD (autoimmune liver disease) and negative for viral markers were screened for autoantibodies, ANA, ASMA, AMA, and LKM, by indirect immunofluorescence. Of these patients, 135 were AMA positive and 132 AMA-M2 positive. Clinical presentation of most of these patients was neither typical of AIH nor PBC. Sera of these patients were further tested for gp 210 and Sp 100. Fifty consecutive consenting patients were typed for HLA class II alleles DR and DQ and their clinical, biochemical, histology and genetic profiles were reviewed to characterize the disease spectrum in north India.

RESULTS

Only 22 of 50 patients had liver histology reports, and could be categorized on the basis of the criteria by Chazouillers et al. Of these 22, 13 had overlap syndrome, eight had classical PBC, whereas one had probable PBC. The remaining 28 could not be suitably categorized due to lack of liver histology. HLA DRB1*03 was found to be significantly associated with the disease in North Indian population.

CONCLUSION

This 13.5-year study demonstrates a definite rising annual incidence of AMA-M2-positive liver disease in north India. Complete evaluation of 50 patients indicated that a hepatitic variant of PBC (PBC-AIH), which is significantly associated with DRB1*03, predominates in north India.

A 50-year experience with autoimmune hepatitis: and where are we now?

BACKGROUND

Autoimmune hepatitis (AIH) as chronic active hepatitis became recognized in the 1940s as a progressive hyperglobulinemic disease affecting younger women attributed to persisting virus infection of the liver: autoimmunity then was barely on the horizon.

EARLY OBSERVATIONS

The lupus erythematosus (LE) cell reported in 1948 signified the presence of antinuclear autoantibodies, promoting perceptions of autoimmunity in certain chronic diseases. Recognition of LE cells in chronic hepatitis led to the designation of 'lupoid hepatitis', with autoimmunity further substantiated by anti-cytoplasmic autoantibodies detected by complement fixation. Next a serum reactant with smooth muscle of rodent stomach was found to have a wider distribution and became identified as an autoantibody to filamentous (F) actin. Therapy with corticosteroids proved effective, particularly combined with azathioprine. Various trials showed greatly improved survival and established modern therapy of AIH. An HLA-based predisposition (B8, DR3) was the first pointer to a genetic etiology.

RECENT ADVANCES

Recombinant or purified autoantigenic substrates have led to automated assays, which, together with improved immunofluorescence procedures, allow serological confidence in diagnosis and institution of effective immunosuppressive therapies. The liver-kidney 'microsomal' autoantigen reactive with cytochrome P450 2D6 distinguishes two serological types of AIH that appear pathogenetically distinct. Molecular characterization of antigens and epitopes remains wanting in type 1 AIH.

FUTURE PROSPECTS

The challenge remains with both types of AIH to elucidate in molecular terms the genetic and environmental basis of pathogenesis from initiation to ultimate progression and cirrhosis (when inadequately treated). Advancing technologies are bringing this goal closer to being attainable.

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.

Personalized medicine for HLA-associated drug-hypersensitivity reactions

Multiple genetic and nongenetic factors can modify the action of a drug, resulting in varied responses to a particular drug across different individuals. Personalized medicine incorporates the comprehensive knowledge of these factors to facilitate the selection of optimal therapy, reduce adverse drug reactions, increase patient compliance and increase the efficiency of therapy. Pharmacogenomics, which integrates the knowledge of an individual’s genetic make-up for diagnostic decisions or therapeutic interventions is closely linked to personalized medicine, and is being increasingly used to prevent adverse drug reactions. There are various reports on genetic associations between particular HLA allotypes and drug hypersensitivities and the strongest associations reported thus far, are with the reverse transcriptase inhibitor, abacavir and HLA-B*5701, the gout prophylactic allopurinol and HLA-B*5801 and the antiepileptic carbamazepine and B*1502, providing a defined disease trigger and suggesting a general mechanism for these associations. Recognizing the strong HLA association, the US FDA has recommended genetic testing before starting abacavir and carbamazepine therapies. To incorporate HLA testing for other drug hypersensitivities and life-threatening reactions it is essential first to establish clear HLA associations, and second, to understand the immune-mechanism by which these drugs induce HLA-linked hypersensitivity. The latter will provide insight into the pathologic mechanisms of drug allergy allowing rational immunotherapy for these life-threatening reactions and the development of alternative drug therapies for hypersensitive patients.

Autoantibodies and liver disease: uses and abuses

Confirming whether a patient has autoimmune liver disease is challenging, given its varied presentation and complex definitions. In the continued absence of pathognomonic serum markers, diagnosis requires evaluation of laboratory investigations and, frequently, a liver biopsy - all of which need to be interpreted in the correct clinical context, with an emphasis on exclusion of viral infections, drug toxicity and metabolic disease. However, clear diagnosis is important for appropriate and timely therapy. Autoantibodies remain important tools for clinicians, and were the first proposed serological markers to aid in differentiating viral from chronic autoimmune hepatitis. Their presence is occasionally considered to be synonymous with autoimmune liver disease - a misinterpretation of their clinical significance. The present article summarizes the serum autoantibodies currently investigated in clinical and research practice, along with a description of their value in adult chronic liver diseases, with an emphasis on their appropriate use in the diagnosis and management of patients with autoimmune liver disease.

Geoepidemiology of autoimmune liver diseases

Autoimmune liver diseases are characterized by immune mediated injury of bile ducts or hepatocytes, thus including cholangiopathies such as primary biliary cirrhosis, primary sclerosing cholangitis, and immunoglobulin G4-associated cholangitis, and autoimmune hepatitis. Although the liver was one of the earliest recognized sites of autoimmune aggression, the aetiology of autoimmune liver diseases remains largely obscure and their clinical management still difficult. Since an ever increasing applicability of immunology to a wide variety of chronic diseases, basic and clinical knowledge on autoimmune liver diseases grow rapidly in the last few years. This review will mainly focus on the available geoepidemiology data of these disorders, but it will deal also on their main clinical characteristics, as well as mechanisms of etiopathogenesis, for each of the above diseases, together with their overlap forms. In particular, we will discuss the major underlying immunomolecular mechanisms of development, the genetic influences, the growing number of immuno-serological diagnostic markers, and the increasingly effective therapeutic possibilities.

Management of autoimmune and cholestatic liver disorders

The management of autoimmune and cholestatic liver disorders is a challenging area of hepatology. Autoimmune and cholestatic liver diseases represent a comparatively small proportion of hepatobiliary disorders, yet their appropriate management is of critical importance for patient survival. In this article, management strategies are discussed, including the indications and expectations of pharmacologic therapy, endoscopic approaches, and the role of liver transplantation.