Author: Leah Farquharson
Editor: Nelly Sadat
Overview
Autoimmune Hepatitis (AIH) is an autoimmune disease that affects the liver (Manns et al., 2015). AIH is an incorrect immune response where the immune system targets the liver (Manns et al., 2015). The exact cause of AIH is currently unknown, but genetic factors may be one of the causes or contributors (Sucher et al., 2019). AIH affects approximately 4 females to every 1 male (Sucher et al., 2019).
If AIH goes untreated for long periods of time, it can lead to liver failure and severe liver diseases such as cirrhosis, acute liver failure, and liver transplant, or even death (Mieli-Vergani et al., 2018). Many patients (around ⅓) with AIH do not show any symptoms and are only diagnosed after a liver function test, which can result in the patient’s AIH remaining untreated (Sucher et al., 2019). Another one-third of patients have severe/ advanced AIH, even cirrhosis, at the time of diagnosis (Gatsoulis et al., 2015).
What Causes Autoimmune Hepatitis?
The exact cause of AIH is unknown (Gatsoulis et al., 2015), but genetic factors may play a role in increasing the risk of developing AIH (Sucher et al., 2019). AIH usually occurs when an individual’s immune system attacks liver cells after being exposed to pathogens or other environmental factors (Mieli-Vergani et al., 2018). This is called “molecular mimicry”, where the immune system targets itself, mistaking it for pathogens due to similar structures (Mieli-Vergani et al., 2018).
As a result of molecular mimicry, Autoimmune hepatitis is often triggered following an infection or sickness (Gatsoulis et al., 2015). Patients with AIH also may have a lower than normal count for cells that suppress inflammatory responses, which may result in uncontrolled immune responses (Mieli-Vergani et al., 2018).
Symptoms
Acute Hepatitis:
- Discomfort/malaise (Gatsoulis et al., 2015),
- Abdominal pain (Gatsoulis et al., 2015),
- Nausea (Gatsoulis et al., 2015)
Autoimmune Hepatitis:
- Fatigue and lack of energy (Gatsoulis et al., 2015),
- Desire to itch (Gatsoulis et al., 2015),
- Pain or inflammation of joints (Manns et al., 2015),
- Abdominal pain (Gatsoulis et al., 2015),
- Weight loss/ Anorexia (Gatsoulis et al., 2015),
- Nausea (Gatsoulis et al., 2015),
Advanced/ Severe AIH:
- High Blood Pressure (Mieli-Vergani et al., 2018),
- Gastrointestinal (GI) bleeding (Mieli-Vergani et al., 2018),
- Yellowing of eyes and skin (Manns et al., 2015)
Risk factors
- Genetic factors (Sucher et al., 2019),
- Sex (females are at increased risk compared to males, 4:1) (Sucher et al., 2019),
- Viruses and other pathogens such as microbes, xenobiotics, antibiotics (nitrofurantoin, minocycline), statins, anti-TNF agents (adalimumab, infliximab) and antibiotics (Manns et al., 2015) (Gatsoulis et al., 2015)
Diagnosis
AIH can present in varying degrees from asymptomatic (no symptoms) to severe symptoms (Gatsoulis et al., 2015). Fatigue is generally the most common symptom of AIH patients, and is sometimes even present in asymptomatic patients (Manns et al., 2015). Other common symptoms include abdominal pain (usually localized at the right upper quadrant), nausea, a desire to itch and discomfort (Gatsoulis et al., 2015).
A liver function test may be performed to assess the function of the liver to determine diagnoses (Sucher et al., 2019). If further testing is required, healthcare providers may perform tests such as blood tests to test the patient’s circulating levels of components like transaminases, immunoglobulin G (IgG) and autoantibodies (Pape et al., 2019). A blood count may also be done to determine T cell levels (Mieli-Vergani et al., 2018).
Treatment
Since AIH is an autoimmune disorder, the most common and most effective treatment is to suppress the immune system (Mieli-Vergani et al., 2018). The sooner the patient starts this treatment after diagnosis, the more effective the treatment will be (Mieli-Vergani et al., 2018). Immunosuppressive treatment is recommended to continue for two years after blood tests show results in the normal range (Pape et al., 2019). Medications such as corticosteroids and azathioprine can also be used, alone or together, to help manage the disease (Mieli-Vergani et al., 2018).
Tests such as glucose monitoring and blood counts should be performed regularly to monitor side effects of medications (Pape et al., 2019). Once a patient’s circulating lab tests are considered normal, the patient is declared to be in complete remission (Manns et al., 2015). The patient should still undergo routine checks to make sure their blood test results stay normal (Pape et al., 2019).
References
Gatsoulis, N. K., Zachou, K., Koukoulis, G. K., & Dalekos, G. N. (2015). Autoimmune hepatitis, one disease with many faces: etiopathogenetic, clinico-laboratory and histological characteristics. World journal of gastroenterology, 21(1), 60–83. DOI: 10.3748/wjg.v21.i1.60
Manns, M. P., Lohse, A. W., & Vergani, D. (2015). Autoimmune hepatitis–Update 2015. Journal of hepatology, 62(1 Suppl), S100–S111. DOI: 10.1016/j.jhep.2015.03.005
Mieli-Vergani, G., Vergani, D., Czaja, A. J., Manns, M. P., Krawitt, E. L., Vierling, J. M., Lohse, A. W., & Montano-Loza, A. J. (2018). Autoimmune hepatitis. Nature reviews. Disease primers, 4, 18017. DOI: 10.1038/nrdp.2018.17
Pape, S., Schramm, C., & Gevers, T. J. (2019). Clinical management of autoimmune hepatitis. United European gastroenterology journal, 7(9), 1156–1163. DOI: 10.1177/2050640619872408
Sucher, E., Sucher, R., Gradistanac, T., Brandacher, G., Schneeberger, S., & Berg, T. (2019). Autoimmune Hepatitis-Immunologically Triggered Liver Pathogenesis-Diagnostic and Therapeutic Strategies. Journal of immunology research, 2019, 9437043. DOI: 10.1155/2019/9437043
