Autoimmune Hepatitis
Introduction
Autoimmune hepatitis (AIH) is not a common disease but with increasing incidence in Asia-Pacific area. Although the etiology and pathogenesis are not completely clear, the disease is the result of loss of autoimmune tolerance in genetically predisposed individuals. AIH is characterized by autoantibodies, and increased amount of gamma globulins in the serum.
Epidemiology
AIH is a rare disease with unknown etiology and may affect all ages, genders and ethnic groups worldwide. It is more seen in females.
What is AIH?
AIH is the result of interactions between genetic susceptibility, predisposing factors, autoantigen response and defective immune system. Autoantibodies target the liver cell (also called hepatocytes).
Predisposing factors
There is a family history of autoimmunity in about 40% of AIH patients. Exposure to drugs, low vitamin D levels and pathogens are known risk factors for AIH. Alterations in intestinal microbiota and translocation of a gut microbe to the liver promote autoimmunity in patients.
Sign and Symptoms
The spectrum of initial manifestations ranges from asymptomatic to acute hepatic failure. Approximately 25% AIH patients do not have any symptoms. The presentation of AIH at onset is variable, ranging from asymptomatic to acute/severe or even fulminant, about one-fourth of AIH patients present with an acute onset, among these patients, some present with the acute exacerbation of chronic AIH, and others present with the true acute AIH without findings of chronic liver disease. One-third of patients at diagnosis have already developed cirrhosis due to delay in diagnosis, irrespective of the presence of symptoms.
The major manifestation is chronic hepatitis and present as sleepiness, fatigue, and general malaise. Fluid in the abdomen, swelling in the lower limbs may be present. The first onset of AIH can occur in pregnant female or after their childbirth. Therefore, early diagnosis and timely treatment are vital for the safety of both mothers and infants.
AIH is usually complicated with other autoimmune diseases like Hashimoto's thyroiditis (10-23%), diabetes mellitus (7-9%), inflammatory bowel disease (2-8%), rheumatoid arthritis (2-5%), Sjögren's syndrome (1-4%), celiac disease (%3.5), psoriasis (3%) and systemic lupus erythe- matosus (SLE) (1-2%)
AIH generally has a chronic presentation with serum ALT and/or AST abnormalities, whereas it can also present as an acute and severe disease with patients presenting in coma (hepatic encephalopathy). Few patients may also develop liver cancer.
Diagnosis
The diagnosis of AIH is based on the presence of typical clinical, laboratory features (including increased serum immunoglobulin G (IgG)/gamma-globulin levels, presence of autoantibodies), combined with pathological examination, and exclusion of other causes of liver diseases [e.g., chronic viral hepatitis, alcoholic liver disease, non-alcoholic steato- hepatitis (NASH), drug-induced liver injury, and Wilson's disease]. Liver biopsy is done to confirm the diagnosis. Serology is very important to the both diagnosis and classification of AIH, serological tests should be completed in all patients for the definitive diagnosis of AIH. Fibroscan is commonly performed.
Management
The aim of AIH treatment is to achieve complete bio- chemical and histological resolution, to suppress inflammatory activity, to prevent fibrosis progression and onset of end-stage liver disease, eventually to prolong survival and improve life quality of patients. Long-term outcome of AIH is now excellent if patients are appropriately managed.
Treatment includes immunosuppressive agents.
Biochemical resolution is defined as reduction of transaminase and IgG levels to normal. Early treatment coincides with favorable long-term prognosis and failure to normalize alanine aminotransferase is a risk factor predicting disease related mortality or transplantation.
IgG levels are also associated with liver inflammatory activity in AIH patients.
Besides, psychological comorbidity of patient is another important issue that needs early recognition and prompt intervention. It was reported that a major depressive syndrome and severe symptoms of anxiety were found to be significantly more frequent in AIH patients compared to the general population, which contributed to an increased risk of noncompliance to AIH therapy
Duration of treatment
Most of AIH patients respond well to treatment and achieve biochemical normalization. But relapse after treatment withdrawal becomes a major issue. Disease relapse is defined as transaminase levels rising abnormally after remission. As mentioned above, it is very common after treatment withdrawal in AIH patients.
Liver transplantation (LT) is an effective therapy for AIH patients with advanced disease and in patients who present with acute liver failure. But recurrence of AIH in the graft after LT is common.
The maternal complication rate during the pregnancy of mother with AIH is 38%, wherein prematurity is mainly due to withholding from adequate treatment. Therefore, pregnant patients with AIH need to receive continuous treatment to reduce the risk of flare.
Living Well with Autoimmune Hepatitis
People with autoimmune hepatitis are advised to avoid alcohol, follow a healthy balanced diet, and take medicines exactly as prescribed. Regular medical check-ups and blood tests are important to monitor liver health. Early treatment and good lifestyle habits can prevent serious complications.
Summary
Autoimmune hepatitis is a treatable liver disease when detected early. Unexplained tiredness, jaundice, or long-lasting digestive symptoms should never be ignored. Seeking medical care on time, following treatment, and spreading awareness can help protect liver health and improve quality of life.
Disclaimer:
This information is provided for educational purposes only. The source of content is found at ILBS and Hepatology International (2021) 15: 223-257
