De Novo Autoimmune Hepatitis Following Liver Transplantation

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

[Treatment of Autoimmune Hepatitis]

Autoimmune hepatitis (AIH) is a chronic liver disease, characterized by elevated levels of transaminases, immunoglobulin G, and positive autoantibodies. The disease course is dynamic and presents heterogeneous disease manifestations at diagnosis. This review summarizes the issues regarding the treatment and monitoring of AIH in adult patients. Glucocorticoids and azathioprine are the first line of treatment. Alternative first-line treatments include budesonide or mycophenolate mofetil (MMF). Although no randomized controlled trials have been performed, MMF, cyclosporine, tacrolimus, 6-mercaptopurine, 6-thioguanine, allopurinol, sirolimus, everolimus, infliximab, or rituximab have been attempted in patients not responding to or intolerant to first-line treatments. Most patients require life-long special monitoring, with or without maintenance treatment.

Differential IgG4-Producing Plasma Cell Infiltration in Non- and Post-Transplant Plasma Cell Hepatitis

Autoimmune hepatitis (AIH), post-transplant recurrent AIH (rAIH), and plasma cell-rich rejection (PCR) are clinical diagnoses with the shared histopathologic hallmark of plasma cell hepatitis (PCH). As these histologically and serologically indistinguishable diagnoses are differentiated by clinical context, it remains uncertain whether they represent distinct immunologic phenomena. Improved understanding of immunoglobulin subclass 4-producing plasma cells (IgG4-PC) has brought attention to IgG4 as an immunophenotypic biomarker. To date, degree and clinical significance of IgG4-PC infiltration in PCH remain elusive. This retrospective, single-center study assessed IgG4-PC infiltration in AIH, rAIH, and PCR via standardized immunohistochemistry analysis. Identified cases from 2005 to 2020 (n = 47) included AIH (treatment-naïve AIH (tnAIH): n = 15 and AIH-flare on treatment (fAIH); n = 10), rAIH (n = 8), and PCR (n = 14) were analyzed and correlated with clinical characteristics. IgG4-Positivity (# IgG4-PC/# pan-IgG-expressing cells) distribution was heterogenous and overlapping [tnAIH: 0.060 (IQR 0.040-0.079), fAIH: 0.000 (0.000-0.033), rAIH: 0.000 (0.000-0.035), PCR: 0.228 (0.039-0.558)]. IgG4-Positivity was inversely correlated with corticosteroid use (p < 0.001). IgG4-Positivity ≥0.500 was associated with rapid AST improvement (p = 0.03). The variable IgG4-Positivity of AIH, rAIH and PCR suggests diverse and overlapping immunopathologic mechanisms and that current diagnostic schemes inadequately capture PCH immunopathology. We propose incorporation of IgG4-Positivity to refine current PCH classification and treatment strategies.

Pathogenesis of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic progressive liver disease whose etiology and pathogenesis are not yet clear. It is currently believed that the occurrence of AIH is closely related to genetic susceptibility and immune abnormalities, and other factors such as environment, viral infection and drugs that may cause immune dysfunction. This article reviews the pathogenesis of AIH and describes the latest research results in the past 5 years.

Hellenic Association for the Study of the Liver Clinical Practice Guidelines: Autoimmune hepatitis

Autoimmune hepatitis (AIH) is a relatively rare acute or chronic liver disease of unknown etiology characterized by large heterogeneity. Its distribution is global, covering all ages, both sexes and all ethnic groups. The aim of the present Clinical Practice Guidelines (CPG) of the Hellenic Association for the Study of the Liver was to provide updated guidance and help to gastroenterologists, hepatologists, internists and general practitioners for AIH diagnosis and management. AIH diagnosis is based on clinicopathological characteristics: namely, polyclonal hypergammaglobulinemia, particularly of immunoglobulin G (IgG), circulating autoantibodies, interface hepatitis on liver histology, absence of viral hepatitis, and a favorable response to immunosuppression. Clinical manifestations at disease onset are variable, ranging from asymptomatic to the acute/severe form. Aminotransferase and bilirubin levels vary, while the presence of hepatitis at the histological level is a prerequisite for diagnosis. Autoantibodies are the hallmark for AIH diagnosis; therefore, the CPG describe the appropriate serological algorithm for their detection. AIH therapy should aim to achieve complete biochemical (normalization of IgG and aminotransferases) and histological remission. All patients who have active disease, even those with cirrhosis, should be treated with individualized and response-guided induction therapy using prednisolone in combination with azathioprine or mycophenolate mofetil as first-line therapy. Immunosuppression should be given for at least 3 years and for at least 2 years after the achievement of complete biochemical response, while a liver biopsy should be recommended before treatment discontinuation. Current CPG are also provided for several specific conditions and difficult-to-treat patients.