What exactly is autoimmune hepatitis (AIH)?
Here is an overview of autoimmune hepatitis (AIH) including some background information on the symptoms, diagnosis, treatment and outlook for patients. There are some links further down the page if you want further information.
As its name indicates AIH is an autoimmune disease. These are conditions in which the body’s immune system wrongly identifies part of the body as something ‘foreign’ (like a bacterium or a virus) and attacks it. There are many such diseases as this process can occur anywhere in the body. Some of the more common ones you may have come across are rheumatoid arthritis where the joints are affected and type 1 diabetes which affects the insulin producing cells in the pancreas. Others, like AIH, are much more rare.
In AIH the liver cells (known as hepatocytes) are attacked causing inflammation and damage. (The word ‘hepatitis’ means any inflammation of the liver and does NOT imply a specific cause or that the person is infectious). Initially that damage is mild but without treatment, in the long term that damage can become irreversible despite the liver’s renowned ability to regenerate itself. The term cirrhosis is used to describe the scarring that develops in the liver, from ANY cause, as a result of long term inflammation.
The reasons why someone might develop AIH (or any other autoimmune disease) are unclear. We know it is due to the body not controlling the immune system perfectly. The current thinking is that an individual needs to have a genetic predisposition of some sort which is then triggered by an infection or something environmental (e.g. a drug or a toxin). Precise triggers in most people are not known, and it may be that the triggers occurred long before the patient becomes ill. Quite often there are members of the patients family, who have other autoimmune diseases, and this highlights the genetic aspect of disease. However AIH is not inherited as such so children of patients with AIH are very unlikely to get disease.
Thus it is not possible to avoid AIH and it isn’t possible to predict who is going to develop it. It has absolutely nothing to do with lifestyle or alcohol consumption, but once someone has AIH they are of course advised to live healthily.
Although there is no cure for AIH, there are lots of good treatments. At present the drugs used by patients focus on medication to minimise the liver inflammation and lower the activity level of the immune system so that further damage is prevented. Whilst in some people it appears to ‘burn out’ and medication can be stopped most find they need long term medication. Importantly before treatments such as steroids and azathioprine were used, this disease carried a poor outlook; this was dramatically changed by these drugs, so whilst they do carry the risk of side effects, for the majority of patients with AIH they are very important and effective, if used correctly.
Symptoms & Diagnosis
In some people AIH develops quickly and symptoms and signs like nausea, fevers, abdominal pain, muscle pain and jaundice rapidly develop. In others the symptoms are more vague such as tiredness and general fatigue and develop over time. If your GP suspects that you have a liver disease after initial tests then they will refer you to a specialist for further investigations. (The specialist that you are likely to see is a Gastroenterologist who deals with diseases of the digestive tract. Some Gastroenterologists specialise in just the liver and they are called Hepatologists. )
There is no single definitive test for AIH. Diagnosis is made via a series of blood tests/scans etc that point towards AIH and may exclude other possible causes of the symptoms, including recent infections or medications. Your doctor will then assess the likelihood of that pattern of results constituting AIH. If it looks likely that it is AIH then a liver biopsy (removing a tiny piece of the liver for further examination) may be carried out to confirm the diagnosis. This is important to help make a clear diagnosis and to understand the severity of the disease in any one patient.
The aim of treatment is to reduce the inflammation and the activity of the immune system and so stop the damage worsening. Initial treatment is likely to be a steroid medication. The most common drug used is prednisolone but an alternative medication, known as budesonide, is being increasingly used which tends to have fewer side effects. These drugs are often started at a high dose and they work quickly to bring the inflammation under control and the blood tests start to return to normal.
At this point the dose will be reduced and your doctor will probably then introduce another medication that is a different immunosuppressant. They work in a different way and allow the dose of steroid to be reduced in the majority of people completely, or to a low maintenance dose in some. The usual drug used for this is called azathioprine.
The important thing about treating AIH is to expect treatment to be prolonged and long term, and to avoid rushing the treatment. Diseases like AIH are not like Asthma- a quick course of steroids is not effective. Slow and steady therapy gets the best results. Steroids are like the “fire extinguisher” and Azathioprine like the “smoke detector” that stops things starting again.
Like all medications some people find that the drugs do not suit them. In these instances alternative drugs are available. These include mercaptopurine, mycophenolate mofetil, tacrolimus and cyclosporine. However in these cases careful consideration needs to be given to using these medicines.
When treatment first starts you will be monitored closely especially via blood tests. This is to make sure the drugs are working and that they are not having any serious side effects. Over time the frequency of tests and hospital visits will reduce. Many people are monitored long term via 6 or 12 monthly visits to the specialist with the GP doing routine blood tests in between visits.
Most people with AIH do very well. Some can be quite ill initially and take time to recover. Others find it takes a while to arrive at the best combination/dosage of medication that bring the blood test results into the normal range whilst having no or minimal side effects. It can take some time to arrive at this stage.
However a proportion of people do continue to experience fatigue despite normal blood test results. The reason for this is unclear. And for some the side effects of the medication (including increased risk of infection) can be significant. It is important that everyone with AIH discusses the risks and benefits of treatments with their doctors so they fully understand these.
Although some people are shown to have liver damage which can span from only minimal scarring all the way through to cirrhosis (significant scarring) if the AIH is managed effectively then hopefully this won’t worsen significantly. As the liver is very resilient this damage does not necessarily seriously affect liver function. However a few people do develop advanced liver damage and for them a liver transplant may be necessary.
The above information has been reviewed by Gideon Hirschfield, Lead Clinician, Autoimmune Liver Disease Programme, Queen Elizabeth Hospital, Birmingham.