The liver has many important functions, including digesting your food and processing and distributing nutrients. The liver is the body’s largest internal organ. The liver is called the body’s metabolic factory because of the important role it plays in metabolism—the way cells change food into energy after food is digested and absorbed into the blood. It also metabolizes medications. Many drug interactions happen because of the metabolic pathways in the liver. If someone is taking two different medications that share a pathway, you’re likely to have a drug interaction. The liver has many other important functions, including:
- taking up, storing, and processing nutrients from food—including fat, sugar, and protein—and delivering them to the rest of the body when needed.
- making new proteins, such as clotting factors and immune factors.
- producing bile. In addition to carrying toxins and waste products out of the body, bile helps the body digest fats and the fat-soluble vitamins A, D, E, and K.
- removing waste products the kidneys cannot remove, such as fats, cholesterol, toxins, and medications.
- metabolizing medications.
This month is Liver Awareness Month and there are many kinds of liver diseases and conditions. Some, like hepatitis, are caused by viruses. Others can be the result of drugs or drinking too much alcohol. And some are caused by an autoimmune disease. Autoimmune hepatitis is a chronic disease in which your body’s immune system attacks the liver and causes inflammation and liver damage. Without treatment, autoimmune hepatitis may get worse and lead to complications, such as cirrhosis.
Autoimmune hepatitis can occur at any age and affects people of all racial and ethnic groups. The disease is more common in girls and women than in boys and men. Experts aren’t sure what causes autoimmune hepatitis. Studies suggest that certain genes make some people more likely to develop autoimmune diseases. In people with these genes, factors in the environment may trigger an autoimmune reaction that causes their immune system to attack the liver.
Some people who have autoimmune hepatitis may also have features of liver diseases that affect their bile ducts—the tubes that carry bile out of the liver—such as:
- primary biliary cholangitis (PBC)
- primary sclerosing cholangitis (PSC)
- bile duct problems that can’t be classified as PBC or PSC
People with autoimmune hepatitis are at risk for having other autoimmune diseases. Examples include:
- celiac disease
- thyroid conditions such as Graves’ disease and Hashimoto’s disease
- rheumatoid arthritis
- type 1 diabetes
- inflammatory bowel disease, such as ulcerative colitis
Symptoms of autoimmune hepatitis include:
- feeling tired
- joint pain
- poor appetite
- pain over the liver, in the upper part of the abdomen
- yellowish color of the whites of the eyes and skin, called jaundice
- darkening of the color of urine
- lightening of the color of stools
- skin conditions, such as rash , psoriasis , vitiligo , or acne
Some people with autoimmune hepatitis have no symptoms. In such cases, doctors may find evidence of liver problems during routine blood tests that leads to a diagnosis of autoimmune hepatitis. People without symptoms at diagnosis may develop symptoms later.
Some people with autoimmune hepatitis don’t have symptoms until they develop complications due to cirrhosis. These symptoms include:
- feeling tired or weak
- losing weight without trying
- bloating from a buildup of fluid in the abdomen, called ascites
- swelling of the lower legs, ankles, or feet, called edema
- itchy skin
In order to diagnose autoimmune hepatitis, your doctor will ask about your symptoms and other factors such as alcohol consumption or diseases you may have such as inflammatory bowel disease or thyroid conditions. They will also check your physical condition including if you have a yellowish color in the whites of your eyes, enlargement of the liver or spleen, tenderness or swelling in the abdomen, or swelling in the lower legs, feet or ankles.
Additionally, your doctor may order one or more blood tests to help diagnose autoimmune hepatitis. These include tests that check levels of the liver enzymes alanine transaminase (ALT) and aspartate transaminase (AST) and check for autoantibodies such as antinuclear antibody (ANA) and anti-smooth muscle antibody (SMA). ALT and AST are particularly important because these liver enzymes are highly elevated in people with autoimmune hepatitis. Doctors check ALT and AST levels to follow the progress of the disease and the response to treatment.
An ultrasound and a liver biopsy may also be necessary to look for the features of autoimmune hepatitis and to check the amount of scarring to find out if you have cirrhosis.
Once diagnosed, your doctor will treat autoimmune hepatitis with medicines that suppress, or decrease the activity of your immune system, reducing your immune system’s attack on your liver. The medicines doctors most often prescribe are corticosteroids —prednisone or prednisolone —with or without another medicine called azathioprine. Treatment can relieve symptoms and prevent or reverse liver damage in many people with autoimmune hepatitis. Early treatment of autoimmune hepatitis can lower the chances of developing cirrhosis and other complications. A minority of people who have no symptoms or only a mild form of the disease may or may not need medicines.