The role of autoantibodies as diagnostic markers of autoimmune hepatitis

Autoimmune hepatitis: Appraisal of current treatment guidelines

Autoimmune hepatitis affects patients of all ages and gender, across all geographic regions. Although still rare, its incidence and prevalence are increasing. Genetic predisposition conveyed by human leucocyte antigen is a strong risk factor for the disease and may be responsible in part for the wide variation in presentation in different geographic regions. Our understanding of the underlying pathogenic mechanisms is evolving and may lead to development of more targeted immunotherapies. Diagnosis is based on elevated levels of serum aminotransferases, gamma globulins, autoantibodies and characteristic findings on histology. Exclusion of other causes of chronic hepatitis is important. Although undiagnosed disease is associated with poor outcomes, it is readily treatable with timely immunosuppressive therapy in the majority of patients. International guidelines are available to guide management but there exists a disparity in the standard treatment regimens. This minireview aims to review the available guidelines and summarize the key recommendations involved in management of this complex autoimmune disease.

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.

Natural History and Treatment Outcomes of Severe Autoimmune Hepatitis

GOALS

The aim of this study was to analyze the natural history and treatment outcomes of autoimmune hepatitis (AIH) variants presenting with severe-AIH.

BACKGROUND

Severe acute presentation is an uncommon manifestation of AIH, and it remains poorly characterized.

MATERIALS AND METHODS

We included 101 patients with AIH from January 2011 to December 2015. Patients were classified as seropositive-AIH and seronegative-AIH. Patients with acute liver failure, acute-on-chronic liver failure, and severe acute hepatitis were defined as severe-AIH patients. Patient characteristics and treatment outcomes with follow-up until 12 months were analyzed between the different groups.

RESULTS

Out of 101 cases, 24 (23.76%) had severe AIH. Of them 9 (37.5%) had severe acute hepatitis, 3 (12.5%) had acute liver failure, and 12 (50%) had acute-on-chronic liver failure. Seronegative-AIH patients presented with severe-AIH significantly more frequently compared with seropositive-AIH patients (50% vs. 20.27%, P=0.022). Severe-AIH had 50% complete responders, 25% partial responders, and 25% treatment failures. Jaundice (88.88% vs. 68.7%, P=0.048), encephalopathy (55.55% vs. 6.66%, P=0.014), and higher international normalized ratio values (2.17±0.60 vs. 1.82±0.14, P=0.038) were factors associated with nonresponse rather than the presence or absence of autoantibodies in severe-AIH. The hazard ratio for predicting remission in the non-severe AIH group as compared with the severe-AIH group was 1.502, which was statistically not significant (95% CI, 0.799-2.827; P=0.205).

CONCLUSION

Approximately 24% of patients with AIH have severe-AIH. Conventional autoantibodies are often absent in severe-AIH; however, it does not alter the outcome. Immunosuppressants should be given expediently in patients with severe-AIH.

Diagnosis and Management of Autoimmune Hepatitis: Current Status and Future Directions

Autoimmune hepatitis is characterized by autoantibodies, hypergammaglobulinemia, and interface hepatitis on histological examination. The features lack diagnostic specificity, and other diseases that may resemble autoimmune hepatitis must be excluded. The clinical presentation may be acute, acute severe (fulminant), or asymptomatic; conventional autoantibodies may be absent; centrilobular necrosis and bile duct changes may be present; and the disease may occur after liver transplantation or with features that suggest overlapping disorders. The diagnostic criteria have been codified, and diagnostic scoring systems can support clinical judgment. Nonstandard autoantibodies, including antibodies to actin, α-actinin, soluble liver antigen, perinuclear antineutrophil antigen, asialoglycoprotein receptor, and liver cytosol type 1, are tools that can support the diagnosis, especially in patients with atypical features. Prednisone or prednisolone in combination with azathioprine is the preferred treatment, and strategies using these medications in various doses can ameliorate treatment failure, incomplete response, drug intolerance, and relapse after drug withdrawal. Budesonide, mycophenolate mofetil, and calcineurin inhibitors can be considered in selected patients as frontline or salvage therapies. Molecular (recombinant proteins and monoclonal antibodies), cellular (adoptive transfer and antigenic manipulation), and pharmacological (antioxidants, antifibrotics, and antiapoptotic agents) interventions constitute future directions in management. The evolving knowledge of the pathogenic pathways and the advances in technology promise new management algorithms.

Brazilian society of hepatology recommendations for the diagnosis and management of autoimmune diseases of the liver

ABSTRACT In order to draw evidence-based recommendations concerning the management of autoimmune diseases of the liver, the Brazilian Society of Hepatology has sponsored a single-topic meeting in October 18th, 2014 at São Paulo. An organizing committee comprised of seven investigators was previously elected by the Governing Board to organize the scientific agenda as well as to select twenty panelists to make a systematic review of the literature and to present topics related to the diagnosis and treatment of autoimmune hepatitis, primary sclerosing cholangitis, primary biliary cirrhosis and their overlap syndromes. After the meeting, all panelists gathered together for the discussion of the topics and the elaboration of those recommendations. The text was subsequently submitted for suggestions and approval of all members of the Brazilian Society of Hepatology through its homepage. The present paper is the final version of the reviewed manuscript organized in topics, followed by the recommendations of the Brazilian Society of Hepatology.

Acute and acute severe (fulminant) autoimmune hepatitis

Autoimmune hepatitis frequently has an abrupt onset of symptoms, and it can present with acute liver failure. The abrupt presentation can indicate spontaneous exacerbation of a pre-existent chronic disease, newly created disease, a superimposed infectious or toxic injury, or new disease after viral infection, drug therapy, or liver transplantation. Deficiencies in the classical phenotype may include a low serum immunoglobulin G level and low or absent titers of the conventional autoantibodies. The original revised diagnostic scoring system of the International Autoimmune Hepatitis Group can guide the diagnostic evaluation, but low scores do not preclude the diagnosis. Liver tissue examination is valuable to exclude viral-related or drug-induced liver injury and support the diagnosis by demonstrating centrilobular necrosis (usually with interface hepatitis), lymphoplasmacytic infiltration, hepatocyte rosettes, and fibrosis. Conventional therapy with prednisone and azathioprine induces clinical and laboratory improvement in 68-75 % of patients with acute presentations, and high dose prednisone or prednisolone (preferred drug) is effective in 20-100 % of patients with acute severe (fulminant) presentations. Failure to improve or worsening of any clinical or laboratory feature within 2 weeks of treatment or worsening of a mathematical model of end-stage liver disease within 7 days justifies liver transplantation in acute liver failure. Liver transplantation for acute severe (fulminant) autoimmune hepatitis is as successful as liver transplantation for autoimmune hepatitis with a chronic presentation and other types of acute liver failure (patient survival >1 year, 80-94 %). Liver transplantation should not be delayed or superseded by protracted corticosteroid therapy or the empiric institution of nonstandard medications.

Autoantibody-negative autoimmune hepatitis

Autoimmune hepatitis has a variable clinical phenotype, and the absence of conventional autoantibodies does not preclude its diagnosis or need for treatment. The goals of this review are to describe the frequency and nature of autoantibody-negative autoimmune hepatitis, indicate its outcome after corticosteroid treatment, and increase awareness of the diagnosis in patients with unexplained acute and chronic hepatitis. The frequency of presumed autoantibody-negative autoimmune hepatitis in patients with acute and acute severe presentations is ≤7%, and its frequency in patients with chronic presentations is 1-34%. Patients with acute presentations can have normal serum γ-globulin levels, centrilobular zone 3 necrosis, and low pre-treatment international diagnostic scores. Liver tissue examination is essential for the diagnosis, and hepatic steatosis can be a co-morbid feature. The comprehensive international scoring system can support but never override the clinical diagnosis pre-treatment, and non-standard serological markers should be sought if the clinical diagnosis is uncertain or the diagnostic score is low. A 3-month treatment trial with corticosteroids should be considered in all patients, regardless of the serological findings, and improvements have occurred in 67-87% of cases. Autoantibody-negative autoimmune hepatitis may be associated with an autoantibody outside the conventional battery; it may have a signature autoantibody that is still undiscovered, or its characteristic autoantibodies may have been suppressed or have a delayed expression. The pathogenic mechanisms are presumed to be identical to those of classical disease. Autoantibody-negative autoimmune hepatitis is an infrequent but treatable disease that must be considered in unexplained acute and chronic hepatitis.

Cryptogenic chronic hepatitis and its changing guise in adults

Cryptogenic chronic hepatitis is a disease that is unexplained by conventional clinical, laboratory and histological findings, and it can progress to cirrhosis, develop hepatocellular carcinoma, and require liver transplantation. The goals of this review are to describe the changing phenotype of cryptogenic chronic hepatitis in adults, develop a diagnostic algorithm appropriate to current practice, and suggest treatment options. The frequency of cryptogenic hepatitis is estimated at 5.4%. Cryptogenic cirrhosis is diagnosed in 5-30% of patients with cirrhosis, and it is present in 3-14% of adults awaiting liver transplantation. Nonalcoholic fatty liver disease has been implicated in 21-63% of patients, and autoimmune hepatitis is a likely diagnosis in 10-54% of individuals. Viral infections, hereditary liver diseases, celiac disease, and unsuspected alcohol or drug-induced liver injury are recognized infrequently in the current cryptogenic population. Manifestations of the metabolic syndrome heighten the suspicion of nonalcoholic fatty liver disease, and the absence of hepatic steatosis does not discount this possibility. The diagnostic scoring system of the International Autoimmune Hepatitis Group can support the diagnosis of autoimmune hepatitis in some patients. Certain genetic mutations may have disease-specificity, and they suggest that some patients may have an independent and uncharacterized disease. Corticosteroid therapy is effective in patients with autoimmune features, and life-style changes and specific therapies for manifestations of the metabolic syndrome are appropriate for all obese patients. The 1- and 5-year survivals after liver transplantation have ranged from 72-85% to 58-73%, respectively.

Performance parameters of the conventional serological markers for autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis is defined by a conventional battery of autoantibodies that may also be present in other liver diseases.

AIMS

To define the performance parameters of the conventional autoantibodies for autoimmune hepatitis, determine the diagnostic implications of simultaneous autoantibody production, and assess the performances of serological assays based on indirect immunofluorescence and enzyme immunoassay.

METHODS

In this study, 265 adults satisfying codified criteria for autoimmune hepatitis and 342 adults who satisfied conventional diagnostic criteria for another chronic liver disease were each assessed for the conventional autoantibodies.

RESULTS

Antinuclear antibodies, smooth muscle antibodies, and antibodies to liver kidney type 1 had sensitivities of only 32, 16, and 1%, respectively, for the diagnosis of autoimmune hepatitis, and their diagnostic accuracy ranged from 56 to 61%. The combination of antinuclear antibodies and smooth muscle antibodies at presentation had superior sensitivity (43%), specificity (99%), positive (97%) and negative (69%) predictabilities, and diagnostic accuracy (74%) than each marker alone. The occurrence of multiple autoantibodies was lower in other chronic liver diseases than in autoimmune hepatitis (8% versus 51%, p < 0.000001). The enzyme immunoassay for antinuclear antibodies had an accuracy that was not discriminative for autoimmune hepatitis (p = 0.06).

CONCLUSIONS

Isolated autoantibodies have a low diagnostic accuracy for autoimmune hepatitis. Concurrent antinuclear antibodies and smooth muscle antibodies have superior performance parameters. The enzyme immunoassay for antinuclear antibodies performs less well than the assay based on indirect immunofluorescence.

Genetic factors affecting the occurrence, clinical phenotype, and outcome of autoimmune hepatitis

Autoimmune hepatitis is a polygenic disorder of unknown cause in which the genetic risk factors that affect occurrence, clinical phenotype, severity, and outcome still are being clarified. The susceptibility alleles in white North American and northern European patients reside on the DRB1 gene, and they are DRB1*0301 and DRB1*0401. These alleles encode a 6 amino acid sequence at positions 67-72 in the DRbeta polypeptide chain of the class II molecules of the major histocompatibility complex. This sequence is associated with susceptibility, and lysine at position DRbeta71 is the key determinant. Molecular mimicry between foreign and self-antigens may explain the loss of self-tolerance and the occurrence of concurrent immune diseases in anatomically distant organs. Disease severity is associated with the number of alleles encoding lysine at DRbeta71 (gene dose) and the number of polymorphisms, including those of the tumor necrosis factor-alpha gene, cytotoxic T lymphocyte antigen-4 gene, and tumor necrosis factor-receptor superfamily gene, that can modify the immune response. Individuals in different geographic regions may have different susceptibility alleles that reflect indigenous triggering antigens, and these may provide clues to the etiologic agent. Knowledge of the genetic predispositions for autoimmune hepatitis may elucidate pathogenic mechanisms, identify etiologic agents, characterize susceptible populations, foresee outcomes, and target new therapies. These lessons may be applicable to autoimmune disease in general.

Autoimmune hepatitis. Part B: diagnosis

Diagnostic criteria have been codified by the International Autoimmune Hepatitis Group, and a scoring system can quantify the strength of the diagnosis and over-ride the impact of absent or inconsistent features. The absence of a definable etiologic agent and precise diagnostic test, implies that the diagnosis may be missed or misapplied. Centrilobular (zone 3) necrosis may be an early form of autoimmune hepatitis and this pattern can transform to the classical pattern of interface hepatitis. An acute severe or fulminant presentation is possible, and different ethnic groups may have different manifestations and outcomes. Asymptomatic patients at presentation commonly become symptomatic, and treatment decisions must be based on objective features of disease severity and not the presence or absence of symptoms. Concurrent autoimmune diseases are frequent, and they may constitute an autoimmune polyglandular syndrome associated with a single gene mutation. Emerging autoantibodies of possible prognostic value are antibodies to soluble liver antigen/liver pancreas, asialoglycoprotein receptor, actin, and liver cytosol type 1. HLA DRB1*03, *04, *03-*04, *07, *13 and DQB1*02 are associated with the occurrence, clinical phenotype and outcome of autoimmune hepatitis. Variant syndromes should be suspected if cholestatic features are prominent and conventional treatment is ineffective.

Autoimmune liver disease

PURPOSE OF REVIEW

The aim of this article is to review studies that improve the diagnosis and treatment of autoimmune hepatitis and suggest new drug and molecular interventions.

RECENT FINDINGS

Elderly patients have an indolent but aggressive disease that responds well to corticosteroid therapy. Variant syndromes are artificial designations that reflect uncertainties regarding the diagnostic limits of classical disease. Antibodies to cyclic citrullinated proteins and complex assays for antibodies to actin and alpha-actinin may have prognostic value. Defects in the number and function of T regulatory cells may enhance cell-mediated cytotoxicity. HLA DRB113 may be a risk factor in some North American patients, and disease outcome may be influenced by the 'dose' of alleles encoding critical residues. Screening for thiopurine methyltransferase deficiency does not predict azathioprine intolerance. Treatment until normalization of the laboratory and histological features reduces the risk of relapse by 30-50%. Adverse outcomes in pregnancy are associated with antibodies to soluble liver antigen/liver pancreas and Ro/SSA.

SUMMARY

Novel serological tests may have prognostic value. Defects in the suppressor activity of regulatory T cells may promote liver injury. Genetic predispositions strongly influence disease occurrence and outcome. Laboratory and histological features should be normal prior to drug withdrawal. Azathioprine toxicities cannot be predicted.