What are the other Names for this Condition? (Also known as/Synonyms)

• Type 1 AIH
• Type 1 Autoimmune Hepatitis
• Type I AIH

What is Type I Autoimmune Hepatitis? (Definition/Background Information)

• Autoimmune hepatitis (AIH) is an autoimmune disease of unknown cause that results in the body’s own immune system attacking the liver. When this happens, abnormal inflammation characteristic of hepatitis occurs, causing damage to the liver. There are three types of AIH
• Type I Autoimmune Hepatitis is the most common form of AIH in North America and is known as the classical type. It is a serious condition that without proper treatment worsens over time. It is typically chronic and can last for many years, causing prolonged damage to the liver
• The signs and symptoms of Type I Autoimmune Hepatitis may include nausea and vomiting, fatigue, abdominal pain, jaundice, and appetite loss. This type of AIH is usually diagnosed during adulthood, and mostly among women
• Without the administration of prompt treatment, cirrhosis i.e., abnormal scarring and hardening of the liver can occur. Progressive scarring not only damages the liver and its functioning ability but can also lead to liver failure. Longstanding untreated Type I Autoimmune Hepatitis can even result in liver failure that often necessitates a liver transplantation
• Currently, there is no cure for Type I Autoimmune Hepatitis, but the signs and symptoms of the condition and its rate of progression can be controlled with appropriate treatment. Type I AIH reportedly responds well to treatment using corticosteroids

Who gets Type I Autoimmune Hepatitis? (Age and Sex Distribution)

• Type I Autoimmune Hepatitis can occur in individuals of all ages and both gender (male and female). However, most of the cases are noted in adults
• Nearly 80% of the cases are observed in females and the female-male ratio is 4:1
• Type I AIH is the most common type in northern America, accounting for over 95% of the cases

What are the Risk Factors for Type I Autoimmune Hepatitis? (Predisposing Factors)

The common risk factors of Type I Autoimmune Hepatitis include:

• Individuals, with autoimmune diseases, such as diabetes mellitus (type 1 diabetes), celiac disease, Hashimoto's thyroiditis, inflammatory bowel disease (IBD) including ulcerative colitis, rheumatoid arthritis (RA), immune thrombocytopenia (ITP), and Graves’s disease
• Gender: AIH occurs at a higher incidence rate in females
• Human leukocyte antigen (HLA) genotype is observed to play a role in the development of this condition; two genotypes are noted, namely HLA DRB1*03 and HLA DRB1*04. The HLA system is a form of gene complex
• Genetic predisposition and family history: In vast majority of Type I AIH, there is no family history, and hence, the current recommendation is not to screen family members for the condition
• Hemolytic anemia
• Presence of bacterial or viral infections has been known to cause the development of the condition. The exact mechanism of how this happens is still being researched into
• Use of certain medications have been reported to be a risk factor for the development of AIH

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Type I Autoimmune Hepatitis? (Etiology)

The exact cause of Type I Autoimmune Hepatitis is currently unknown. It is caused by a combination of environmental, genetic, and immunological factors. The immunological factors may constitute certain preexisting autoimmune disorders such as diabetes, inflammatory bowel diseases, rheumatoid arthritis, Graves’s disease, among other conditions.

• Generally, AIH occurs when the immune system is compromised and begins to function abnormally. This causes the immune system to attack the liver, which is healthy, causing liver inflammation or hepatitis
• Some drugs and certain infections have been found to contribute to this abnormal response of the immune system. While, stoppage of the particular drug or treating the infection may alleviate the symptoms, attack on the liver and inflammation may continue to take place even after such remedial measures are taken
• Individuals with certain HLA genotypes have a higher risk for AIH; those with HLA DRB1*04 genotype present underlying autoimmune disorders to a much greater extent than those with HLA DRB1*03 genotype
• Some researchers have proposed that certain genetic factors may predispose an individual to AIH. This may be a reason why this condition has been observed to run in families, in some rare cases

What are the Signs and Symptoms of Type I Autoimmune Hepatitis?

The severity of signs and symptoms of Type I Autoimmune Hepatitis may vary from one individual to another. In some, it may be mild, resulting in a delayed diagnosis of the condition. Some individuals are diagnosed incidentally during wellness checkups. In other individuals, the signs and symptoms may be severe. 

The signs and symptoms may include

• Jaundice (yellowing of the skin)
• Icterus (yellowing of the eyes)
• Loss of appetite
• Nausea and vomiting
• Fatigue
• Abdominal pain and swelling 
• Skin rashes/itching
• Dark-colored urine
• Light-colored stools 
• Joint pain
• Enlarged or swollen liver (hepatomegaly)
• Amenorrhea in women (absence of menstruation)

The signs and symptoms of the underlying condition (such as autoimmune disease), if any present, may be noted.

How is Type I Autoimmune Hepatitis Diagnosed?

The diagnosis of Type I Autoimmune Hepatitis is based upon a combination of clinical findings and lab test abnormalities. It is important to rule out other causes of chronic hepatitis, such as alcohol-induced hepatitis, viral hepatitis, and drug-induced hepatitis, before arriving at a diagnosis of AIH.

The following tests and exams may be used in the diagnosis of Type I AIH:

• A complete medical history and a thorough physical examination. The physician may request for a list of all medications that are currently being taken
• Often times, the physician may recommend blood tests to assess the functioning of liver, in order to confirm a diagnosis. The liver contains a large number of enzymes. When the liver is injured, these enzymes are released into blood and they may be analyzed through various blood tests:
  • Testing for common enzymes such as aspartate transaminase (AST) and alanine transaminase (ALT)
  • Patients with Type I AIH have increased amounts of ANA (anti-nuclear antibodies) and ASMA (anti-smooth muscle antibodies) in their blood
• Liver biopsy: If blood tests are not adequate in diagnosing AIH, a liver biopsy may be performed. During this procedure, a small sample of the liver is removed from the body and sent to the laboratory for analysis. If a pathologist finds abnormalities with the liver, a diagnosis of AIH may be confirmed
• Radiological studies, such as USG of abdomen and CT abdomen, are usually not helpful in diagnosing AIH. However, they are often performed to rule-out other conditions causing similar signs and symptoms
• A differential diagnosis may be performed to rule-out the following conditions that present similar signs and symptoms prior to arriving at a diagnosis of Type I AIH

It is important to note that individuals diagnosed with AIH have a higher incidence of primary sclerosing cholangitis (PSC), a long-term and progressive condition of the liver and gallbladder. If PSC is detected, then a magnetic resonance cholangiopancreatography (MRCP; an imaging technique) may be recommended.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Type I Autoimmune Hepatitis?

If Type I Autoimmune Hepatitis is left untreated, it can result in certain complications. Some of the complications include:

• Accumulation of fluid within the abdomen, known as ascites
• Formation of esophageal varices resulting in vomiting of blood
• Since AIH results in liver inflammation without adequate and proper treatment, it can ultimately lead to chronic liver injury. This may worsen and lead to cirrhosis (scarring) of the liver
• Untreated Type I AIH can cause total liver failure, although it is quite rare
• In extreme cases, cirrhosis that is caused by AIH can lead to hepatocellular carcinoma (a type of liver cancer), which can be fatal

How is Type I Autoimmune Hepatitis Treated?

The most important component of treatment for Type I Autoimmune Hepatitis is a prompt and accurate diagnosis of the condition. Following a diagnosis, the treatment measures may include:

• Use of immunosuppressive medications:
  • These medications suppress the immune system and lower its ability to function, preventing it from attacking the liver
  • This includes the administration of corticosteroids such as prednisone, prednisolone, and/or azathioprine. Type I AIH is known to respond well with corticosteroid therapy
  • This is the most effective treatment for AIH, as it not only stops progression of the disease, but also helps in reversing the liver damage
• If immunosuppressive drugs are not effective in treating the condition, the healthcare provider may recommend a liver transplant. This procedure involves removal of the damaged liver from the body and replacing it with a healthy liver from a suitable donor
• Periodic liver biopsy may be performed to determine the level of scarring and inflammation

How can Type I Autoimmune Hepatitis be Prevented?

Currently, there are no known prevention methods for Type I Autoimmune Hepatitis. Also, presently, there are no known methods to prevent the body from developing an autoimmune disease.

• As there are no preventative measures that can be taken, it is important to have regular follow-up visits with the healthcare practitioner, if an individual is diagnosed with AIH, or is at a high risk for developing the condition
• Undertaking early and appropriate treatment of an underlying autoimmune disease may help in lowering one’s risk for AIH
• If the use of certain medications places an individual at an elevated risk for this liver condition, it is advisable to check with the physician on the same

What is the Prognosis of Type I Autoimmune Hepatitis? (Outcomes/Resolutions)

• The prognosis of Type I Autoimmune Hepatitis largely depends on the severity of the disease. Individuals, who are diagnosed early and undergo prompt treatment, have a much better prognosis than those with delayed diagnosis and inadequate treatment
• Patients, who respond well to immunosuppressive drugs, are usually able to recover from AIH and their prognosis is good. Similarly, patients who receive liver transplants are also able to recover from the disease. In both cases, the life expectancies are comparable with those of the general population
• Individuals with HLA DRB1*03 genotypes are known to be diagnosed with Type I AIH at a much younger age, are not known to respond well to corticosteroid treatment, and hence, have less favorable outcomes usually due to liver failure
• Typically, individuals with AIH and with other coexisting autoimmune diseases, do not do as well. In such a scenario, the individual is at a higher risk for other diseases and infections (opportunistic conditions), and their ability to recover is lowered
• Some individuals may need lifelong treatment. Withdrawing treatment may result in a relapse of the condition

Additional and Relevant Useful Information for Type I Autoimmune Hepatitis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/diseases-conditions/immune-related-disorders/