Baseline IL-2 and the AIH score can predict the response to standard therapy in paediatric autoimmune hepatitis

Advancing Biologic Therapy for Refractory Autoimmune Hepatitis

Biologic agents may satisfy an unmet clinical need for treatment of refractory autoimmune hepatitis. The goals of this review are to present the types and results of biologic therapy for refractory autoimmune hepatitis, indicate opportunities to improve and expand biologic treatment, and encourage comparative clinical trials. English abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed. Rituximab (monoclonal antibodies against CD20 on B cells), infliximab (monoclonal antibodies against tumor necrosis factor-alpha), low-dose recombinant interleukin 2 (regulatory T cell promoter), and belimumab (monoclonal antibodies against B cell activating factor) have induced laboratory improvement in small cohorts with refractory autoimmune hepatitis. Ianalumab (monoclonal antibodies against the receptor for B cell activating factor) is in clinical trial. These agents target critical pathogenic pathways, but they may also have serious side effects. Blockade of the B cell activating factor or its receptors may disrupt pivotal B and T cell responses, and recombinant interleukin 2 complexed with certain interleukin 2 antibodies may selectively expand the regulatory T cell population. A proliferation-inducing ligand that enhances T cell proliferation and survival is an unevaluated, potentially pivotal, therapeutic target. Fully human antibodies, expanded target options, improved targeting precision, more effective delivery systems, and biosimilar agents promise to improve efficacy, safety, and accessibility. In conclusion, biologic agents target key pathogenic pathways in autoimmune hepatitis, and early experiences in refractory disease encourage clarification of the preferred target, rigorous clinical trial, and comparative evaluations.

Serum Biomarkers for Autoimmune Hepatitis Type 1: the Case for CD48 and a Review of the Literature

In autoimmune hepatitis (AIH), the persisting inflammation contributes to fibrosis progression, for which conventional biochemical markers manifest relatively unsatisfactory prediction. Herein, we assessed the value of serum CD48 (sCD48) as an indicator for inflammation and fibrosis in AIH type 1. The levels of sCD48 were detected first in an exploratory cohort using ELISA. In this cohort, compared with healthy controls (4.90 ng/mL, P < 0.0001), primary biliary cholangitis (7.32 ng/mL, P < 0.0001), and non-alcoholic fatty liver disease (7.76 ng/mL, P < 0.0001), sCD48 levels were elevated in AIH (12.81 ng/mL) and correlated with histological inflammation and fibrosis. Further using multivariate logistic regression analysis, sCD48 was identified as an independent predictor for both significant inflammation (G3-4) and advanced fibrosis (S3-4). Two predictive scores, based on sCD48, were constructed for diagnosing significant inflammation and advanced fibrosis (sCD48-AIH-SI and sCD48-AIH-AF, respectively). Using these data as a premise, predictive abilities were subsequently evaluated and verified in a validation cohort. In the exploratory cohort, the area under the receiver operating characteristic curve of sCD48 and sCD48-AIH-SI, for significant inflammation, were 0.748 and 0.813, respectively. Besides, during treatment follow-up, sCD48 levels gradually decreased from immunosuppression initiation to re-evaluation biopsy, in parallel with aspartate transaminase, total sera IgG, and fibrosis-4 score. For AIH patients in a re-evaluation biopsy cohort, sCD48 could predict significant fibrosis (S2-4). Further using immunohistochemistry, hepatic CD48 expression was elevated in AIH patients and decreased after treatment. In conclusion, sCD48 and sCD48-based predictive scores predict histological inflammation and fibrosis in AIH-1. Detecting sCD48 might help in the clinical management of AIH.

Exploring the Pathogenic Role and Therapeutic Implications of Interleukin 2 in Autoimmune Hepatitis

Interleukin 2 is essential for the expansion of regulatory T cells, and low-dose recombinant interleukin 2 has improved the clinical manifestations of diverse autoimmune diseases in preliminary studies. The goals of this review are to describe the actions of interleukin 2 and its receptor, present preliminary experiences with low-dose interleukin 2 in the treatment of diverse autoimmune diseases, and evaluate its potential as a therapeutic intervention in autoimmune hepatitis. English abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed. Interleukin 2 is critical for the thymic selection, peripheral expansion, induction, and survival of regulatory T cells, and it is also a growth factor for activated T cells and natural killer cells. Interleukin 2 activates the signal transducer and activator of transcription 5 after binding with its trimeric receptor on regulatory T cells. Immune suppressor activity is increased; anti-inflammatory interleukin 10 is released; pro-inflammatory interferon-gamma is inhibited; and activation-induced apoptosis of CD8⁺ T cells is upregulated. Preliminary experiences with cyclic injections of low-dose recombinant interleukin 2 in diverse autoimmune diseases have demonstrated increased numbers of circulating regulatory T cells, preserved regulatory function, improved clinical manifestations, and excellent tolerance. Similar improvements have been recognized in one of two patients with refractory autoimmune hepatitis. In conclusion, interferon 2 has biological actions that favor the immune suppressor functions of regulatory T cells, and low-dose regimens in preliminary studies encourage its rigorous investigation in autoimmune hepatitis.

Autoimmune hepatitis: from immunopathogenesis to diagnostic and therapeutic innovation

PURPOSE OF REVIEW

To understand the pathogenesis of autoimmune hepatitis (AIH) and the accuracy of diagnosis and treatment options that have improved lately. We summarize the latest research.

RECENT FINDINGS

Concerning pathogenesis of AIH, different groups have identified pieces of the puzzle that fit together well: An altered microbiome in the gut results in a proinflammatory response in the liver. This response is built by type II natural killer cells and CD4 T cells with an inflammatory phenotype and marked tumor necrosis factor production. When looking specifically at autoantigenic CD4 T cells, these have a B-helper phenotype on transcriptomic analysis. This explains not only elevation of immunoglobulins in AIH, but also mechanistically the effect of anti-B-cell substances in treatment. Diagnosis is now facilitated by an improved diagnostic score for AIH also recognizing modern techniques for autoantibody detection. Treatment in the future will increasingly be focused on reducing dosage and duration of steroid exposition. In addition, B-cell-targeted treatments have been evaluated with considerable success.

SUMMARY

Research in the past 18 months has improved the understanding of pathogenesis and thereby opened a number of possible treatment options. In addition, steroid use is cautioned by the recent findings.

Serum Leptin Serves as an Inflammatory Activity Marker and Predicts Steroid Response in Autoimmune Hepatitis

BACKGROUND AND AIM

Adipocytokines, especially leptin is involved in a wide spectrum of proinflammatory functions, in various tissues. This study was carried out to assess the role of serum leptin in autoimmune hepatitis.

METHODS

Serum leptin was analyzed in treatment naïve autoimmune hepatitis (AIH, n = 48) patients and compared with the primary biliary cholangitis (PBC, n = 16), chronic hepatitis C (CHC, n = 16) and healthy controls (n = 15). Serum leptin correlation was assessed on liver function tests, disease activity, T regulatory cells (Tregs), and Th17 cells in the liver biopsies and on steroid treatment response in AIH.

RESULTS

Serum leptin was higher in AIH than in PBC, CHC, and HC {AIH: 335 (106.2-580), PBC: 126 (52-381.2), CH: 67 (3.7-133.5) and HC: 66 (40-157.5) ng/ml; P = 0.001}. In AIH cases; serum leptin correlated with hepatic activity index (r = 0.896; P < 0.001); serum transaminases (aspartate aminotransferases (AST) = 0.615, P < 0.001, alanine aminotransferases (ALT) = 0.551, P < 0.001). It had inverse correlation with Treg cells (P = -0.711, P < 0.001) and positively correlated with Th17 cells (r = 0.650, P < 0.001) in the liver biopsy tissue. High serum leptin was found to be associated with steroid partial or nonresponsiveness at 4 weeks (P = 0.002).

CONCLUSION

Serum leptin is indicative of higher AIH activity and a reduced number of Tregs cells in liver biopsy tissue. Leptin negative cases have more chances of steroid responsiveness and could help in the selection of AIH cases for appropriate therapy.

Novel Diagnostic and Therapeutic Strategies in Juvenile Autoimmune Hepatitis

Juvenile autoimmune hepatitis (JAIH) is a rare, chronic, inflammatory disease of the liver characterized by a complex interaction between genetic, immunological, and environmental factors leading to loss of immunotolerance to hepatic antigens. It affects both children and adolescents, most commonly females, and its clinical manifestations are quite variable. JAIH is progressive in nature and if left untreated may lead to cirrhosis and terminal liver failure. Although JAIH was first described almost 50 years ago, there have been few significant advances in the clinical management of these patients, both in terms of available diagnostic tools and therapeutic options. Aminotransferase activity, class G immunoglobulins and autoantibodies are the biomarkers used to diagnose AIH and monitor treatment response alongside clinical and histological findings. Despite their utility and cost-effectiveness, these biomarkers are neither an accurate expression of AIH pathogenic mechanism nor a precise measure of treatment response. Current standard of care is mainly based on the administration of steroids and azathioprine. This combination of drugs has been proven effective in inducing remission of disease in the majority of patients dramatically improving their survival; however, it not only fails to restore tolerance to hepatic autoantigens, but it also does not halt disease progression in some patients, it is often needed life-long and finally, it has deleterious side-effects. The ideal therapy should be enough selective to contrast immune-mediated live damage while preserving or potentiating the ability to develop permanent tolerance vs. pathogenic autoantigens. By reviewing the state of the art literature, this article highlights novel diagnostic and therapeutic strategies for managing pediatric AIH with a special focus on new strategies of immunotherapy. These promising tools could improve the diagnostic algorithm, more accurately predict disease prognosis, and provide targeted, individualized treatment.

[Autoimmune hepatitis-standard and second-line therapy]

BACKGROUND

Autoimmune hepatitis (AIH) is a rare chronic inflammatory liver disease. Like other autoimmune diseases, the incidence continues to rise and, if left untreated, it has a detrimental natural course.

AIM

Description of the current etiology, diagnosis and management of AIH.

MATERIALS AND METHODS

Summary of current national as well as international guidelines and highlighting recently published studies.

RESULTS AND CONCLUSION

In addition to autoantibody testing and liver histology, the diagnosis of AIH is based on the exclusion of other relevant liver diseases. The standard of care with prednisolone ± azathioprine, which has been well established for decades, significantly improves long-term survival. The therapeutic aim is the complete normalization of aminotransferases and immunoglobulin G. Budesonide, an alternative topical steroid with fewer systemic side effects, was approved for AIH therapy in non-cirrhotic patients in 2011. The therapeutic goal of complete biochemical remission is achieved in about 80% of patients and liver transplantation is rarely necessary. The majority of patients require life-long immunosuppressive therapy because of high relapse rates after discontinuation of immunosuppressants. Currently used second-line therapies are based on uncontrolled monocentric studies with single substances. Therefore, clear recommendations from international expert groups are lacking. These second-line therapies are not approved by the regulatory authorities such as the Food and Drug Administration or the European Medicines Agency.