Cutting edge issues in autoimmune hepatitis

Narciclasine ameliorated T cell mediated acute liver injury through activating AMPK pathway

Hepatitis is closely related to cirrhosis and liver cancer, and it is vital that we develop new drugs and identify new drug targets. Traditional Chinese medicine has demonstrated excellent curative effects on liver diseases. The ingredients from Chinese herbals are important source for drug development in the treatment of hepatitis. Here, we found that narciclasine (NCS), a major component extracted from narcissus bulbs, showed hepatoprotective effect against concanavalin A (Con A) induced hepatitis. NCS treatment significantly reduced hepatocyte death, hepatic inflammatory cells infiltration, and serum cytokine levels in Con A challenged mice. We further observed that NCS directly inhibited Con A induced splenocytes proliferation and cytokine production in vitro. RNA-seq results showed that genes related to immune response were upregulated in Con A treated CD4⁺ T cells, which were down-regulated in the presence of NCS. Moreover, the AMPK pathway had been found activated in response to NCS treatment, suggesting a potential target for NCS targets. In conclusion, our results reveal that NCS is a powerful immunosuppressor against T cell activation, thus leading to protection against Con A induced liver injury in mice. These findings provide new insights into the use of natural products in the treatment of autoimmune hepatitis.

A reasoned approach to the treatment of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease affecting all ages, characterised by elevated transaminase and immunoglobulin G levels, positive autoantibodies, interface hepatitis on histology and good response to immunosuppressive treatment. If untreated, it has a poor prognosis. The aim of this review is to analyse AIH therapeutic interventions with reference to our knowledge of the pathogenesis of AIH. Standard treatment, based on steroids and azathioprine, leads to disease remission in 80-90% of patients. Alternative first-line treatment with budesonide is effective in adults, but less so in the juvenile form of AIH; first-line treatment with ciclosporin does not provide convincing advantages compared to standard treatment. Second-line treatments are needed for patients not responding or intolerant to first-line standard management. Mycophenolate mofetil is the most widely used second-line drug, and has good efficacy particularly for patients intolerant to azathioprine, but is teratogenic. Only few and heterogeneous data on calcineurin inhibitors and m-TOR inhibitors are available. Biologicals, including anti-tumour necrosis factor- α and anti-CD20 monoclonal antibodies, have given ambivalent results and may have severe side-effects. Clinical trials with new therapeutic options aiming at targeting B lymphocytes and proinflammatory cytokines, or expanding regulatory T cells to restore tolerance are ongoing.

Development and validation of a new simplified diagnostic scoring system for pediatric autoimmune hepatitis

BACKGROUND

Children with autoimmune hepatitis (AIH) often exhibit particular features. Accordingly, seven pediatric-specific criteria have been proposed.

AIM

To develop a prediction model based on them, transform it into a scoring system and study its accuracy.

METHODS

A cohort of children under study for liver disease was consecutively selected. AIH diagnosis was based on classical criteria. Already proposed pediatric criteria were recorded. The best possible regression model was selected, and the beta coefficient of each criterion was translated into a whole number (points). Total scores were obtained following the points system and the best cut-off was calculated. Subsequently, accuracy of the diagnostic score was studied in the validation set.

RESULTS

Among 212 included patients, 100 had AIH. The score included 5 criteria: autoantibodies (0-2 points), hypergammaglobulinemia, exclusion of viral hepatitis, exclusion of Wilson's disease (1 point each) and liver histology (3 points). In addition, a normal cholangiogram is mandatory. The validation set was formed of 70 patients (24 with AIH). In this subsample, a score of ≥6 renders a sensitivity/specificity of 95.8%/100%. The area under the receiver operating characteristic curve was 97.1%.

CONCLUSION

Pediatric-specific criteria for the diagnosis of AIH can be reliably used as a scoring system.

Accuracy of the Simplified Criteria for Autoimmune Hepatitis in Children: Systematic Review and Decision Analysis

BACKGROUND/OBJECTIVES

Several studies have been conducted on the accuracy of simplified criteria for autoimmune hepatitis that were presented in 2008 as an alternative to original criteria. Our purpose is to summarize the evidence available regarding their accuracy in children and to carry out a basic clinical decision analysis based on it.

METHODS

Electronic and manual searches were performed with keywords related to diagnostic validity terms. Data from included studies were extracted, and summary estimates of accuracy measures were calculated. An effect model was chosen depending on heterogeneity, and the presence of publication bias was also studied. Therapeutic threshold was calculated based on the already published data. Through a Bayesian approach, simplified criteria's clinical utility was simulated, taking into account the meta-analyzed indicators and several assumptions on the prevalence of autoimmune hepatitis.

RESULTS

The search yielded 166 studies, four of which were finally included, providing a total population of 437 patients. Pooled sensitivity and specificity of the simplified criteria for the diagnosis of autoimmune hepatitis in children was 77% and 95%, respectively, with a diagnostic odds ratio of 67. No evidence of publication bias was found. For prevalences ranging from 8.5 to 85.7, the predictive value of either a positive or a negative result moved beyond the therapeutic threshold (estimated at 56%).

CONCLUSIONS

The simplified criteria show high specificity and moderate sensitivity for the diagnosis of autoimmune hepatitis in children. A positive result can justify starting a therapeutic assay, but a negative result does not seem sufficient to rule out this condition.

Accuracy of the 2008 Simplified Criteria for the Diagnosis of Autoimmune Hepatitis in Children

PURPOSE

Classical criteria for diagnosis of autoimmune hepatitis (AIH) are intended as research tool and are difficult to apply at patient's bedside. We aimed to study the accuracy of simplified criteria and the concordance with the expert diagnosis based on the original criteria.

METHODS

A cohort of children under study for liver disorder was selected through consecutive sampling to obtain the prevalence of AIH within the group of differential diagnoses. AIH was defined, based on classical criteria, through committee review of medical reports. Validity indicators of the simplified criteria were obtained in an intention to diagnose approach. Optimal cut-off and the area under the receiver operating characteristic (ROC) curve were calculated.

RESULTS

Out of 212 cases reviewed, 47.2% were AIH. For the optimal cut-off (6 points), the simplified criteria showed a sensitivity of 72.0% and a specificity of 96.4%, with a 94.7% positive and a 79.4% negative predictive value. The area under the ROC curve was 94.3%. There was a good agreement in the pre-treatment concordance between the classical and the simplified criteria (kappa index, 0.775).

CONCLUSION

Simplified criteria provide a moderate sensitivity for the diagnosis of AIH, but may help in indicating treatment in cases under suspicion with 6 or more points.

Challenges in the Standardization of Autoantibody Testing: a Comprehensive Review

Standardization and harmonization are complementary tools to achieve higher testing quality in laboratory medicine. Both are of great relevance and are strongly needed in autoimmune diagnostics, due to the impressive advance in basic research and technological development observed in this diagnostic field in recent years that has led to the introduction of many new tests and new analytical methods. It is, therefore, essential that this strong innovative thrust is translated into clinical practice in a coordinated way to avoid confusion and the risk of potentially harmful errors for the patient. However, while standardization of antibody assays is a very complex task, harmonization of procedures and behaviors is a more feasible target and should necessarily include all the phases of the total testing process-in the pre-analytical phase, appropriateness of test requests, harmonization of autoantibody terminology, and adoption of uniform nomenclature for laboratory tests; in the analytical phase, harmonization of measurements, and sharing of test profiles and diagnostic algorithms; and in the post-analytical phase, harmonization of data reporting, and criteria for interpreting immunoserological results, especially harmonization of units, reference intervals, decision limits, and definition and notification of critical values. We here provide and discuss some examples of harmonization initiatives related to anti-nuclear antibodies, TSH receptor, and anti-thyroid peroxidase antibodies and to antibodies associated with autoimmune hepatitis and with celiac disease. These initiatives could be the starting steps to achieve a wider consensus and a closer interaction among stakeholders in the path of autoimmune diagnostics harmonization to enhance clinical effectiveness and provide greater patient safety.

Autoantibody and human leukocyte antigen profiles in children with autoimmune liver disease and their first-degree relatives

OBJECTIVE

Familial clustering of juvenile autoimmune liver disease (AILD), including autoimmune hepatitis and autoimmune sclerosing cholangitis (ASC), is rare, despite a high prevalence of autoimmune disorders in AILD families.

METHODS

To investigate this discrepancy, we measured autoantibodies diagnostic for AILD, anti-nuclear, anti-smooth muscle, anti-liver kidney microsomal type 1, anti-liver cytosol type 1, and anti-soluble liver antigen antibodies, and human leukocyte antigen profiles in 31 patients and 65 of their first-degree relatives (FDR). The autoantibody profile was compared with that of 42 healthy subjects (HS).

RESULTS

Autoantibodies were detected in 71% (22/31) patients. Anti-nuclear antibody or anti-smooth muscle antibody were present in 4/65 FDR (6.2%). HS were negative for all autoantibodies. The frequencies of homozygous HLA DRB1*0301 (DR3) genes and haplotype A1-B8-DR3 were higher in the patients (25% and 43%) than in FDR (9% and 27%) and HS (0% and 16%). The frequencies of disease-protective genes DR4 and/or DR15 were lower in the patients (25%) than in FDR (42%) and HS (42%). Only 1 family contained 2 patients with AILD, 1 with ASC and 1 with primary sclerosing cholangitis. Both patients possessed A1-B8-DR3 genes, the ASC being homozygous and the primary sclerosing cholangitis heterozygous. Six FDR had nonhepatic autoimmune disorders, none being autoantibody positive.

CONCLUSIONS

Homozygosity for DR3 plays a major role in the predisposition to juvenile AILD. Diagnostic autoantibodies for AILD are rare among patients' FDR and not linked to clinical manifestation of AILD.

Autoimmunity in 2012

The initiation and perpetuation of autoimmunity recognize numerous checkpoints, from the genomic susceptibility to the breakdown of tolerance. This latter phenomenon includes the loss of B cell anergy and T regulatory cell failure, as well as the production of autoantibodies and autoreactive T cells. These mechanisms ultimately lead to tissue injury via different mechanisms that span from the production of proinflammatory cytokines to the chemotaxis of immune cells to the target sites. The pathways to autoimmunity have been widely investigated over the past year and resulted in a number of articles in peer-reviewed journals that has increased by nearly 10 % compared to 2011. We herein follow on the attempt to provide a brief discussion of the majority of articles on autoimmune diseases that were published in the major immunology journals in the previous solar year. The selection is necessarily arbitrary and may thus not be seen as comprehensive but reflects current research trends. Indeed, 2012 articles were mostly dedicated to define new and old mechanisms with potential therapeutic implications in autoimmunity in general, though based on specific clinical conditions or animal models. As paradigmatic examples, the environmental influence on autoimmunity, Th17 changes modulating the autoimmune response, serum autoantibodies and B cell changes as biomarkers and therapeutic targets were major issues addressed by experimental articles in 2012. Further, a growing number of studies investigated the sex bias of autoimmunity and supported different working hypotheses to explain the female predominance, including sex chromosome changes and reproductive life factors. In conclusion, the resulting scenario illustrates that common factors may underlie different autoimmune diseases and this is well represented by the observed alterations in interferon-α and TGFβ or by the shared signaling pathways.

Less travelled roads in clinical immunology and allergy: drug reactions and the environmental influence

Allergy and clinical immunology are examples of areas of knowledge in which working hypotheses are dominant over mechanistic understanding. As such, sometimes scientific efforts follow major streams and overlook some epidemiologically prevalent conditions that thus become underestimated by the research community. For this reason, we welcome the present issue of Clinical Reviews in Allergy and Immunology that is dedicated to uncommon themes in clinical immunology and allergy. First, comprehensive discussions are provided for allergy phenomena of large potential impact in clinical practice such as reactions to cephalosporins or aspirin-induced asthma and in everyday life such as allergies to food additives or legumes. Further, the issue addresses other uncommon themes such as urticaria and angioedema, cercarial dermatitis, or late-onset inflammation to soft tissue fillers. Last, there will be discussion on transversal issues such as olfactory defects in autoimmunity, interleukin 1 beta pathway, and the search for new serological markers in chronic inflammation. As a result, we are convinced that this issue will be of help to clinicians involved in internal medicine as well as to allergists and clinical immunologists. More importantly, we are convinced that these discussions will be of interest also to basic scientists for the numerous translational implications.

Diagnostic criteria of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic immune-mediated liver disorder characterised by female preponderance, elevated transaminase and immunoglobulin G levels, seropositivity for autoantibodies and interface hepatitis. Presentation is highly variable, therefore AIH should be considered during the diagnostic workup of any increase in liver enzyme levels. A set of inclusion and exclusion criteria for the diagnosis of AIH have been established by the International Autoimmune Hepatitis Group (IAIHG). There are two main types of AIH: type 1, positive for anti-nuclear (ANA) and/or anti-smooth muscle antibodies (SMAs) and type 2, defined by the presence of anti-liver kidney microsomal antibody type 1 (LKM-1) and/or anti-liver cytosol type 1 (LC-1) autoantibodies. The central role of autoantibodies in the diagnosis of AIH has led the IAIHG to produce a consensus statement detailing appropriate and effective methods for their detection. Autoantibodies should be tested by indirect immunofluorescence at an initial dilution of 1/40 in adults and 1/10 in children on a freshly prepared rodent substrate that includes kidney, liver and stomach sections to allow for the simultaneous detection of all reactivities relevant to AIH. Anti-LKM-1 is often confused with anti-mitochondrial antibody (AMA) if rodent kidney is used as the sole immunofluorescence substrate. The identification of the molecular targets of anti-LKM-1 and AMA has led to the establishment of immuno-assays based on the use of the recombinant or purified autoantigens. Perinuclear anti-nuclear neutrophil antibody (p-ANNA) is an additional marker of AIH-1; anti soluble liver antigen (SLA) antibodies are specific for autoimmune liver disease, can be present in AIH-1 and AIH-2 and are associated with a more severe clinical course. Anti-SLA are detectable by ELISA or radio-immuno-assays, but not by immunofluorescence. AIH is exquisitely responsive to immunosuppressive treatment, which should be instituted promptly to prevent rapid deterioration and promote remission and long-term survival.

Clinical significance of detection of anti-neutrophil cytoplasmic antibodies in patients with autoimmune hepatitis

AIM: To explore the significance of detection of anti-myeloperoxidase antibody (ANCAs) in the diagnosis of autoimmune hepatitis (AIH).

METHODS: In total, 48 AIH patients, 190 non-AIH patients and 50 healthy volunteers were included in this retrospective study. Enzyme-linked immunosorbent assay (ELISA) was used to detect anti-RP3, anti -MPO and ALA, while indirect immunofluorescence (IIF) was employed to detect ANCAs.

RESULTS: The positive rates of ANCA, p-ANCA, x-ANCA and ALA in the AIH group had significant differences compared with the non-AIH group (except for PSC). The positive rate of anti-MPO was significantly higher in the AIH group than in the non-AIH group (P < 0.01). Of all specimens in the AIH group, only 1 was positive for c-ANCA and PR3 simultaneously. There was a good correlation between anti-MPO and ANCA, between anti-MPO and p-ANCA, and between ALA and x-ANCA in the AIH group. The kappa values of anti-MPO and ANCA as well as anti-MPO and p-ANCA were 0.819 and 0.875, respectively, showing excellent agreement.

CONCLUSION: Combined detection of ANCAs is helpful for the diagnosis of AIH and AIH subtypes.

The interplay between regulatory and effector T cells in autoimmune hepatitis: Implications for innovative treatment strategies

Autoimmune hepatitis is an immuno-mediated inflammatory liver disorder of unknown etiology and is characterized by hypergammaglobulinaemia, circulating autoantibodies and interface hepatitis. The disease may often present as an acute icteric hepatitis, or run an insidious and progressive course, and in most of the cases it is expected to evolve toward liver cirrhosis and end-stage liver failure, without prompt and appropriate treatment with steroids and other immunosuppressive drugs. Nonetheless, several patients are non-responsive or become non-tolerant to conventional therapy with prednisone/prednisolone with or without azathioprine. Recent findings highlight the role of the interplay between CD4+CD25+ regulatory T cells and Th17 cells in the pathogenesis of autoimmune hepatitis. A numerical and functional imbalance between regulatory and effector cells in favor of the latter appears to be pivotal in the progression of the disease. In addition, the intra-hepatic microenvironment of autoimmune hepatitis is particularly rich in pro-inflammatory cytokines such as IL-6, IL-17, IL-23, IL-1β which play a crucial role in perpetuating and expanding effector cells and subsequent liver damage, whereas regulatory T cells are greatly disadvantaged and inhibited in such polarized habitat. Novel therapeutic interventions should aim at modulating the intra-hepatic pro-inflammatory milieu while favoring the expansion of regulatory T cells. Liver autoantigen-specific regulatory T cells generated and expanded in vitro from patients' own cells might offer a potentially curative approach to autoimmune hepatitis by inhibiting effector cells of the same specificity without inducing pan-immunosuppression.

Cutting-edge issues in autoimmunity and allergy of the digestive system

Autoimmunity and allergy involving the digestive system may be considered as paradigmatic for numerous common themes of complex diseases secondary to tolerance breakdown. Among gastrointestinal autoimmune diseases, for example, we encounter diseases in which a clear environmental trigger is identified (i.e., celiac disease), serum autoantibodies are most specific (i.e., primary biliary cirrhosis), or in which the disease pathophysiology is clearly understood (i.e., autoimmune gastritis). Similarly, it is intriguing that the gastrointestinal tract and the liver circulation represent the crucial environment for the development of immune tolerance. This issue is dedicated to the discussion of recent concepts while identifying two major common issues, i.e., the need for serum biomarkers and the role of vitamin D. Other common themes characterize the etiology and effector mechanisms of these and other autoimmune diseases and are discussed in each cutting-edge overview.