Immunoserological and histological differences between autoimmune hepatitis with acute presentation and chronic autoimmune hepatitis

A case of A20 haploinsufficiency complicated by autoimmune hepatitis

AIM

A20 haploinsufficiency (HA20) is a recently described autoinflammatory disease that manifests symptoms similar to those of Behçet's disease. However, little is known about the involvement of the liver in HA20. Here, we report a case of HA20 complicated by autoimmune hepatitis (AIH).

CASE PRESENTATION

A 33-year-old woman was previously diagnosed with HA20 and chronic thyroiditis, and was treated with prednisolone (PSL; 7.5 mg/day) and levothyroxine sodium hydrate (125 μg/day). She experienced general malaise and jaundice, and biochemical evaluation revealed elevated liver function with an aspartate aminotransferase level of 817 U/L, an alanine aminotransferase level of 833 U/L, and a total bilirubin of 8.3 mg/dL. Pathological evaluation of the liver biopsy revealed interface hepatitis and the patient was diagnosed with acute exacerbation of AIH. Upon increasing the PSL dose to 60 mg/day, the liver enzyme levels rapidly decreased. During tapering of PSL, azathioprine 50 mg/day was added, and there was no relapse of AIH with combination therapy of PSL 7 mg/day and azathioprine 50 mg/day.

CONCLUSION

This is the first report of biopsy-proven AIH in an Asian patient with HA20. This case has significant implications for the pathogenesis and treatment of AIH in patients with HA20.

Ultrastructural Profile Combined with Immunohistochemistry of a Hepatic Progenitor Cell Line in Pediatric Autoimmune Hepatitis: New Insights into the Morphological Pattern of the Disease

Considering that the heterogenic population of a hepatic progenitor cell line (HPCL) can play a vital role in autoimmune hepatitis (AIH), we decided to conduct pioneering retrospective evaluation of these cells in pediatric AIH by means of transmission electron microscopy (TEM). The aim of the study was to assess the ultrastructure of the HPCL in children with untreated AIH. Ultrastructural analysis of the HPCL population, preceded by immunohistochemical staining for cytokeratin 7 (CK7), was performed using pretreatment liver biopsies from 23 children with clinicopathologically diagnosed AIH. Immunohistochemical assessment for CK7 allowed detection of proliferating immature epithelial cells differentiating towards periportal and intralobular intermediate hepatocytes without marked formation of ductular reactions in AIH children. Using TEM, we distinguished three morphological types of HPCs: I—the most undifferentiated progenitor cells; III—intermediate hepatocyte-like cells; II—intermediate bile duct cells. Most frequent were the cells differentiating towards hepatocytes, most rare—those differentiating towards cholangiocytes. The results indicate that an HPCL may be an important source of hepatocyte regeneration. Ultrastructural analyses of the HPCL population, combined with immunohistochemistry for CK7, might be a useful tool to evaluate liver cell regeneration, including fibrogenesis, and may help better understand the morphological pattern of the disease, in pediatric AIH. Frequent appearance of an HPCL in the vicinity of fibrotic foci, often accompanied by hyperactive Kupffer cells and transitional hepatic stellate cells, may indicate their significant involvement in liver fibrogenesis.

Increasing incidence of acute autoimmune hepatitis: a nationwide survey in Japan

The Japanese diagnostic guidelines for autoimmune hepatitis (AIH) were proposed in 2014. This study aimed to determine the trends and characteristics of AIH based on a Japanese nationwide survey. Data for 796 patients who were newly diagnosed with AIH from 2014 to 2017 were collected from January to March, 2019 from 54 hospitals throughout Japan. Clinical characteristics, including treatment, were compared with those reported in a prior 2015 survey. The population had a median age of 63 years at diagnosis, and the male to female ratio was 1:5.3. The numbers of women was significantly lower in this survey than in the 2015 survey. Moreover, the incidence of AIH with histological acute hepatitis increased significantly from 11.0 to 21.7%. The changes in the laboratory findings, such as in transaminase and immunoglobulin G levels and antinuclear antibody titers, as well as in prednisolone treatment, reflected an increasing incidence of acute AIH. The clinical characteristics of AIH changed rapidly, in parallel with the increasing incidence of acute AIH. The elucidation and diagnosis of AIH with acute hepatitis are important in the management of AIH.

Differences in autoimmune hepatitis based on inflammation localization

Histopathology is essential for the diagnosis and evaluation of disease activity of autoimmune hepatitis (AIH). We aimed to elucidate the characteristics of AIH from the localization of inflammation. We re-evaluated a nationwide survey that was performed in Japan in 2018 of AIH patients diagnosed between 2014 and 2017. A total of 303 patients were enrolled, and the clinical and treatment characteristics were compared between the patients with predominantly portal inflammation (230 patients) or lobular inflammation (73 patients). AIH patients with lobular inflammation had a higher probability of being diagnosed with acute hepatitis than those with portal inflammation. Liver enzyme levels were higher in patients with lobular inflammation, whereas immunoglobulin G levels were higher in patients with portal inflammation. The prevalence of an alanine aminotransferase level < 30 U/L after 6 months of treatment was significantly higher in patients with lobular inflammation than in those with portal inflammation (81.7% vs. 67.3%, P = 0.046). The localization of inflammation may be useful for evaluating the onset of AIH.

Acute onset of autoimmune hepatitis in children and adolescents

BACKGROUND

Autoimmune hepatitis (AIH) is a rare progressive liver disease, which manifests as acute hepatitis in 40%-50% of pediatric cases. This refers predominantly to spontaneous exacerbations of previously unrecognized subclinical AIH with laboratory and histological signs of chronic hepatitis, or to acute exacerbations of known chronic disease. Only a few of these patients fulfill criteria for acute liver failure (ALF).

METHODS

Forty children diagnosed with AIH in our center between 2000 and 2018 were included in this study. All of them fulfilled revised diagnostic criteria of the International Autoimmune Hepatitis Group (IAIHG) for probable or confirmed AIH, and other etiologies of liver diseases were excluded. Patients were divided into two groups: acute AIH (A-AIH) or chronic AIH (C-AIH).

RESULTS

Acute onset of AIH occurred in 19/40 children (48%). Six of them fulfilled the criteria of ALF with coagulopathy and encephalopathy. Five of 6 children with ALF suffered from exacerbation of previously undiagnosed chronic AIH, among which 4 children were histologically confirmed as micronodular cirrhosis. The remaining one patient had fulminant AIH with centrilobular necrosis, but no histological signs of previous chronic liver damage. We observed significantly lower levels of albumin, higher levels of aminotransferases, bilirubin, INR, IgG, higher IAIHG score and more severe histological findings in A-AIH than in C-AIH. No differences in patient age and presence of autoantibodies were observed between A-AIH and C-AIH. All children, including those with ALF and cirrhosis, were treated with corticosteroids, and are alive and achieved AIH remission. Liver transplant was not indicated in any patient.

CONCLUSION

Rapid and accurate diagnosis of A-AIH may be difficult. However, timely start of immunosuppressive therapy improves prognosis and decreases number of indicated liver transplantations in children with AIH.

Acute onset autoimmune hepatitis: Clinical presentation and treatment outcomes

INTRODUCTION AND AIM

Autoimmune hepatitis (AIH) may present acutely, which can rapidly progress to fulminant type. This pattern has been described worldwide but is generally under-reported. We aim to describe the clinical presentation and treatment outcomes of patients with acute onset AIH.

MATERIALS AND METHODS

A multicenter retrospective cohort study of patients with acute onset AIH. Clinical, biochemical, and histological data were analyzed and the outcomes were reported.

RESULTS

Seventy patients were included. The mean age was 33.8±1.5 years and 58.6% were female. Upon initial presentation, 94% had jaundice, 44% had fatigue, 31% had pruritus, and 29% had abdominal pain. Biochemical analysis revealed elevated alanine transaminase (733±463.6), aspartate transaminase (699±423), and total bilirubin (210±181.8). Antinuclear antibody (ANA) was positive in 61% of patients, anti-smooth muscle antibody (ASMA) in 69%, and both in 31%; immunoglobulin G (IgG) was elevated in 86% of patients. Advanced fibrosis was found in 39%. Complete remission was achieved in 74.3%, two patients required liver transplants and six died. No specific biomarkers were identified as predictive of remission; however, advanced age was associated with poor prognosis.

CONCLUSION

Acute onset AIH is a disease that requires early diagnosis and management. We confirmed that elevated transaminases are the hallmark of biochemical presentation of acute AIH. High IgG, ANA and ASMA are typically present in such patients upon presentation, however, their absence does not totally exclude the diagnosis. Initial response to treatment was excellent; however, the long-term mortality was higher than the general patient population.

Interleukin-33/ST2-Mediated Inflammation Plays a Critical Role in the Pathogenesis and Severity of Type I Autoimmune Hepatitis

Interleukin (IL)‐33 was recently described as a new member of the IL‐1 family; members of this family have proinflammatory activity. IL‐33 and its soluble receptor ST2 (sST2) have been implicated in the pathogenesis of autoimmune diseases. This study investigated serum IL‐33 and sST2 in type I autoimmune hepatitis (AIH) and the relationship of these molecules with clinical and pathologic parameters. Subjects included 65 patients with AIH who were diagnosed in our hospital. The control population included 17 healthy individuals and 36 patients with primary biliary cholangitis (PBC). Mean age at AIH diagnosis was 55.5 years, and the male‐to‐female ratio was 6:59. Serum IL‐33 and sST2 levels were significantly higher in patients with AIH than in those with PBC or controls. Importantly, immunohistochemistry revealed high IL‐33 expression in liver sections from patients with AIH. In particular, serum IL‐33 and sST2 levels were significantly higher in acute‐onset AIH than in chronic‐onset AIH. Serum IL‐33 levels were positively correlated with serum total bilirubin (TB), alanine aminotransferase (ALT), and necroinflammatory activity in AIH. We performed multivariate logistic regression analysis and found serum IL‐33 levels to be independent factors for severe activity. Serum sST2 levels were positively correlated with serum TB and ALT and negatively correlated with serum albumin and prothrombin time in AIH. In particular, serum sST2 levels were significantly higher in severe symptoms of AIH. Serum IL‐33 and sST2 levels in patients with AIH responsive to treatment with prednisolone were significantly decreased after treatment. Interestingly, serum IL‐33 level was associated with a significantly increased risk of relapse. Conclusion: IL‐33/ST2 may play an important role in the pathogenesis and severity of AIH and may be a promising target for AIH therapy.

This study aimed to investigate serum IL‐33 and sST2 in type I autoimmune hepatitis (AIH) patients and its relationship with clinical and pathological parameters. Multivariate analysis was performed, and serum IL‐33 levels were independent factors for severe activity and relapse. Our findings suggest that IL‐33/ST2 may play an important role in the pathogenesis and severity of AIH and may present a promising target for AIH therapy.