Management of Difficult Cases of Autoimmune Hepatitis. Curr Gastroenterol Rep. 2016;18:9. [PMID: 26780632 DOI: 10.1007/s11894-015-0484-7]

IL-15-producing splenic B cells play pathogenic roles in the development of autoimmune hepatitis

Background & Aims

B-cell depletion therapy with an anti-CD20 is an effective treatment strategy for patients with refractory autoimmune hepatitis (AIH). However, the mechanisms underlying B-cell action are unclear.

Methods

Herein, we used the adeno-associated virus IL-12 model, in which hepatic IL-12 expression triggers liver injuries characteristic of AIH. We also analysed the clinical samples of patients with AIH.

Results

B-cell depletion using anti-CD20 or splenectomy was found to improve liver functions and decrease the cytotoxic CD8⁺ T-cell (cytotoxic T lymphocyte [CTL]) count in the liver. This improvement was reversed by the adoptive transfer of splenic B cells derived from AAV IL-12-treated mice to splenectomised mice as it caused the hepatic CTL count to increase. RNA-sequencing analysis identified IL-15 as a key factor in pathogenic B cells, which promotes CTL expansion and subsequent migration to the liver via the CXCL9/CXCR3 axis. Indeed, IL-15 neutralisation ameliorated hepatitis by suppressing splenic and hepatic CTLs in vivo. The close distribution of B220⁺ B cells and CD8⁺ T cells in the spleen of AIH mice suggested mutual interactions. Mechanistically, IFNγ and CD40L/CD40 signalling were indispensable for the expression of IL-15 in B cells, and in vitro co-culture experiments revealed that splenic CD40L⁺CD8⁺ T cells promoted IL-15 production in B cells, which led to CTL expansion. In patients with AIH, high serum IL-15 concentration and IL-15⁺ B-cell counts, positively correlating with serum alanine aminotransferase levels, support translation and potential therapeutic targeting in human AIH.

Conclusions

This investigation elucidated the roles of IL-15-producing splenic B cells that occur in concert with pathogenic CD8⁺ T cells during the development of AIH.

Impact and Implications

IL-15-producing B cells were shown to exacerbate experimental AIH via cytotoxic T lymphocyte expansion. CD40L⁺CD8⁺ T cells promoted IL-15 expression in B cells, indicating the mutual interaction of both cells. High serum IL-15 concentrations, IL-15⁺ B-cell counts, and CD40L⁺IL-15Rα⁺CD8⁺ T-cell counts were confirmed in the blood of patients with AIH.

Natural history and management of refractory autoimmune hepatitis

Content available: Author Interview and Audio Recording.

Identification and characterization of dynamically regulated hepatitis-related genes in a concanavalin A-induced liver injury model

Background: Concanavalin A (ConA)-induced liver damage of mice is a well-established murine model mimicking the human autoimmune hepatitis (AIH). However, the pathogenic genes of the liver injury remain to be revealed.

Methods: Using time-series liver transcriptome, top dynamic genes were inferred from a set of segmented regression models, and cross-checked by weighted correlation network analysis (WGCNA). AIH murine models created by ConA were used to verify the in vivo effect of these genes.

Results: We identified 115 top dynamic genes, of which most were overlapped with the hub genes determined by WGCNA. The expression of several top dynamic genes including Cd63, Saa3, Slc10a1, Nrxn1, Ugt2a3, were verified in vivo. Further, Cluster determinant 63 (Cd63) knockdown in mice treated with ConA showed significantly less liver pathology and inflammation as well as higher survival rates than the corresponding controls.

Conclusion: We have identified the top dynamic genes related to the process of acute liver injury, and highlighted a targeted strategy for Cd63 might have utility for the protection of hepatocellular damage.

Novel HLA Class I Alleles Outside the Extended DR3 Haplotype Are Protective against Autoimmune Hepatitis

HLA class II allele, DRB1*03:01, is the most common genetic risk factor for autoimmune hepatitis (AIH), but other unrecognized HLA related risks exist.

Autoimmune Hepatitis: Clinical Characteristics and Predictors of Biochemical Response to Treatment

BACKGROUND AND OBJECTIVES

Autoimmune hepatitis (AIH) is an important cause of chronic liver disease. Aim of this study was to evaluate the clinical characteristics and factors predicting response to treatment in patients with AIH.

METHODS

In this prospective observational study, all patients diagnosed with AIH from 2017 to 2019 were included. Biochemical response to the treatment was checked three months after the start of the treatment. Response was considered good if transaminases normalized, or poor if either remained persistently elevated or improved partially.

RESULTS

Of the total 56 patients, 41 (73.2%) were females. Mean age was 29.5 (±16.9) years. About half (53.6%; n = 30) the patients were aged < 25 years and majority [47 (83.9%)] were cirrhotic. Autoimmune serology was negative in 20 (35.7%). Seronegativity was associated with severe necroinflammation (P = 0.015) and esophageal varices (P = 0.021). Response to treatment was good in 34 (60.7%). Bivariate analysis showed that good response to treatment was associated with pre-treatment serum IgG level > 20 g/L (P = 0.024), presence of pseudorosettes on histopathology (P = 0.029) and three months post-immunosuppression serum total bilirubin < 2mg/dL (P < 0.001). Multivariate logistic regression analysis showed that only pre-treatment serum IgG >20 g/L (P = 0.038) and post-treatment serum total bilirubin <2 mg/dL (P = 0.004) were independent predictors of good response to treatment.

CONCLUSION

Majority of AIH patients in our study were young and cirrhotic. A negative autoimmune serology does not rule out AIH and liver biopsy may be required to confirm the diagnosis. Seronegative AIH rapidly progresses to advanced liver disease. Response to treatment is good with pre-treatment IgG > 20g/L and post-treatment total bilirubin < 2 mg/dL.

Extrahepatic Autoimmune Diseases are Prevalent in Autoimmune Hepatitis Patients and Their First-Degree Relatives: Survey Study

Background

Concurrent autoimmune illnesses contribute to increased medical burden and reduced quality of life in patients with autoimmune hepatitis (AIH). The frequency of coexisting autoimmune conditions among North American patients with AIH and their families remains incomplete. Challenges associated with disease capture in the electronic medical record, high study costs, and geographic spread of patients are formidable barriers to understanding the extent of concurrent autoimmune conditions in these groups.

Objective

This objective of this study was to examine the frequency of extrahepatic autoimmune diseases (EHAD) among AIH cases and healthy controls as well as their first-degree relatives using social networking sites (SNS).

Methods

We developed a 53-question survey detailing the history of autoimmune diseases. A survey link was posted at routine intervals within specific Web-based cohorts on SNS. Healthy controls, without self-reported autoimmune liver disease, were recruited from Amazon’s Mechanical Turk. Continuous variables were summarized using medians and P values obtained with the Wilcoxon rank-sum test. Categorical variables were compared using the chi-square test.

Results

Compared with controls (n=1162), cases (n=306) were more likely to be older (median age: 49 vs 33 years), female (284/306, 92.81% vs 955/1162, 82.18%), and have an EHAD (128/306, 41.83% vs 218/1162, 18.76%; P=.001). The most frequent EHADs among cases were thyroid disease (49/306, 16.01% ), Sjögren syndrome (27/306, 8.82%), Raynaud phenomenon (23/306, 7.52%), and psoriasis (22/306, 7.19%). Overall, 55.88% (171/306) of cases and 35.71% (1601/4484) of controls reported at least 1 first-degree relative (FDR) with a history of EHAD (P=.001). Cases had a significantly higher risk of EHAD than controls after the adjustment for age, sex, race, and body mass index: odds ratio 2.46 (95% CI 1.8-3.3); P=.001.

Conclusions

Patients with AIH report higher prevalence of coexistent EHAD than healthy controls, and their FDRs are also more likely to have autoimmune disorders.

Potential triggering factors of acute liver failure as a first manifestation of autoimmune hepatitis-a single center experience of 52 adult patients

AIM

To investigate potential triggering factors leading to acute liver failure (ALF) as the initial presentation of autoimmune hepatitis (AIH).

METHODS

A total of 565 patients treated at our Department between 2005 and 2017 for histologically-proven AIH were retrospectively analyzed. However, 52 patients (9.2%) fulfilled the criteria for ALF defined by the "American Association for the Study of the Liver (AASLD)". According to this definition, patients with "acute-on-chronic" or "acute-on-cirrhosis" liver failure were excluded. Following parameters with focus on potential triggering factors were evaluated: Patients' demographics, causation of liver failure, laboratory data (liver enzymes, MELD-score, autoimmune markers, virus serology), liver histology, immunosuppressive regime, and finally, outcome of our patients.

RESULTS

The majority of patients with ALF were female (84.6%) and mean age was 43.6 ± 14.9 years. Interestingly, none of the patients with ALF was positive for anti-liver kidney microsomal antibody (LKM). We could identify potential triggering factors in 26/52 (50.0%) of previously healthy patients presenting ALF as their first manifestation of AIH. These were drug-induced ALF (57.7%), virus-induced ALF (30.8%), and preceding surgery in general anesthesia (11.5%), respectively. Unfortunately, 6 out of 52 patients (11.5%) did not survive ALF and 3 patients (5.7%) underwent liver transplantation (LT). Comparing data of survivors and patients with non-recovery following treatment, MELD-score (P < 0.001), age (P < 0.05), creatinine (P < 0.01), and finally, ALT-values (P < 0.05) reached statistical significance.

CONCLUSION

Drugs, viral infections, and previous surgery may trigger ALF as the initial presentation of AIH. Advanced age and high MELD-score were associated with lethal outcome.

Glassy droplet inclusions within the cytoplasm of Kupffer cells: A novel ultrastructural feature for the diagnosis of pediatric autoimmune hepatitis

Since Kupffer cells/macrophages (KCs/MPs) may be involved in the pathogenesis of autoimmune hepatitis (AIH), this pioneer study was undertaken to evaluate KCs/MPs in pediatric AIH in transmission-electron microscope.

METHODS

Ultrastructural analyses were performed using liver biopsies from 14 children with clinicopathologically diagnosed AIH.

RESULTS

In all AIH children, ultrastructural findings revealed changes in the cells lining sinusoidal vessels, especially KCs/MPs and endothelial cells. KCs/MPs showed increased phagocytic activity and damaged mitochondria, frequently with accompanying intense fibrosis. In 10/14 AIH patients, the cytoplasm of sinusoidal KCs/MPs contained characteristic glassy droplet inclusions. They were round, sharply circumscribed, and contained homogeneous material and distinct translucent fields. Their ultrastructure was identical with the Russel bodies of plasma cells, which were also found in liver biopsies in the same patients.

CONCLUSION

Ultrastructural identification of characteristic cytoplasmic droplets with glassy appearance in KCs/MPs, never before described in AIH, provides a useful novel morphological feature in the diagnosis of this disease.

Endogenous n-3 Polyunsaturated Fatty Acids Attenuate T Cell-Mediated Hepatitis via Autophagy Activation

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) exert anti-inflammatory effects in several liver disorders, including cirrhosis, acute liver failure, and fatty liver disease. To date, little is known about their role in immune-mediated liver diseases. In this study, we used fat-1 transgenic mice rich in endogenous n-3 PUFAs to examine the role of n-3 PUFAs in immune-mediated liver injury. Concanavalin A (Con A) was administered intravenously to wild-type (WT) and fat-1 transgenic mice to induce T cell-mediated hepatitis. Reduced liver damage was shown in Con A-administrated fat-1 transgenic mice, as evidenced by decreased mortality, attenuated hepatic necrosis, lessened serum alanine aminotransferase activity, and inhibited production of pro-inflammatory cytokines (e.g., TNF-α, IL-6, IL-17A, and IFN-γ). In vivo and in vitro studies demonstrated that n-3 PUFAs significantly inhibited the activation of hepatic T cells and the differentiation of Th1 cells after Con A challenge. Further studies showed that n-3 PUFAs markedly increased autophagy level in Con A-treated fat-1 T cells compared with the WT counterparts. Blocking hepatic autophagy activity with chloroquine diminished the differences in T cell activation and liver injury between Con A-injected WT and fat-1 transgenic mice. We conclude that n-3 PUFAs limit Con A-induced hepatitis via an autophagy-dependent mechanism and could be exploited as a new therapeutic approach for autoimmune hepatitis.