Liver fibrosis occurs when the healthy tissue of your liver becomes scarred and therefore cannot work as well. Fibrosis is the first stage of liver scarring. Later, if more of the liver becomes scarred, it’s known as liver cirrhosis.
While some animal studies have shown the potential for the liver to regenerate or heal itself, once liver damage is done in humans, the liver doesn’t usually heal. However, medications and lifestyle changes can help to keep fibrosis from getting worse.
What are the stages of liver fibrosis?
There are several different scales of liver fibrosis staging, where a doctor determines the degree of liver damage. Since staging can be subjective, each scale has its own limitations. One doctor may think a liver is slightly more scarred than another. However, doctors will usually assign a stage to liver fibrosis because it helps the patient and other doctors understand the degree to which a person’s liver is affected.
One of the more popular scoring systems is the METAVIR scoring system. This system assigns a score for “activity” or the prediction of how fibrosis is progressing, and for the fibrosis level itself. Doctors can usually assign this score only after taking a biopsy or tissue sample of a piece of the liver. The activity grades range from A0 to A3:
- A0: no activity
- A1: mild activity
- A2: moderate activity
- A3: severe activity
The fibrosis stages range from F0 to F4:
- F0: no fibrosis
- F1: portal fibrosis without septa
- F2: portal fibrosis with few septa
- F3: numerous septa without cirrhosis
- F4: cirrhosis
Therefore, a person with the most severe disease form would have an A3, F4 METAVIR score.
Another scoring system is Batts and Ludwig, which grades fibrosis on a scale of grade 1 to grade 4, with grade 4 being the most severe. The International Association of the Study of the Liver (IASL) also has a scoring system with four categories that range from minimal chronic hepatitis to severe chronic hepatitis.
What are the symptoms of liver fibrosis?
Doctors don’t often diagnose liver fibrosis in its mild to moderate stages. This is because liver fibrosis doesn’t usually cause symptoms until more of the liver is damaged.
When a person does progress in their liver disease, they may experience symptoms that include:
- appetite loss
- difficulty thinking clearly
- fluid buildup in the legs or stomach
- jaundice (where the skin and eyes appear yellow)
- unexplained weight loss
According to a , an estimated 6 to 7 percent of the world’s population has liver fibrosis and doesn’t know it because they don’t have symptoms.
What are the causes of liver fibrosis?
Liver fibrosis occurs after a person experiences injury or inflammation in the liver. The liver’s cells stimulate wound healing. During this wound healing, excess proteins such as collagen and glycoproteins build up in the liver. Eventually, after many instances of repair, the liver cells (known as hepatocytes) can no longer repair themselves. The excess proteins form scar tissue or fibrosis.
Several types of liver diseases exist that can cause fibrosis. These include:
- autoimmune hepatitis
- biliary obstruction
- iron overload
- nonalcoholic fatty liver disease, which includes nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH)
- viral hepatitis B and C
- alcoholic liver disease
According to , the most common cause of liver fibrosis is nonalcoholic fatty liver disease (NAFLD), while the second is alcoholic liver disease due to long-term excesses of drinking alcohol.
Treatment options for liver fibrosis usually depend upon the underlying cause of the fibrosis. A doctor will treat the underlying illness, if possible, to reduce the effects of liver disease. For example, if a person drinks alcohol excessively, a doctor may recommend a treatment program to help them stop drinking. If a person has NAFLD, a doctor may recommend making dietary changes to lose weight and taking medications to promote better blood sugar control. Exercising and losing weight may also help to reduce the disease’s progression.
A doctor may also prescribe medications known as antifibrotics, which have been shown to reduce the likelihood that liver scarring will occur. The antifibrotic prescribed usually depends on the underlying medical condition. Examples of these treatments include:
- chronic liver disease: ACE inhibitors, such as benazepril, Lisinopril, and ramipril
- hepatitis C virus: a-Tocopherol or interferon-alpha
- nonalcoholic steatohepatitis: PPAR-alpha agonist
While researchers are conducting many tests to try to find medications that can reverse the effects of liver fibrosis, there aren’t any medications that can accomplish this currently.
If a person’s liver fibrosis advances to where their liver is very scarred and doesn’t work, a person’s only treatment is often to receive a liver transplant. However, the waiting list is long for these transplant types and not every person is a surgical candidate.
Traditionally, doctors considered taking a liver biopsy the “gold standard” of testing for liver fibrosis. This is a surgical procedure where a doctor would take a tissue sample. A specialist known as a pathologist will examine the tissue for the presence of scarring or fibrosis.
Another option is an imaging test known as transient elastography. This is a test that measures how stiff the liver is. When a person has liver fibrosis, the scarred cells make the liver stiffer. This test uses low-frequency sound waves to measure how stiff liver tissue is. However, it’s possible to have false positives where the liver tissue may appear stiff, but a biopsy doesn’t show liver scarring.
However, doctors have been able to use other tests that don’t require surgery to determine the likelihood a person may have liver fibrosis. These blood tests are usually reserved for those with known chronic hepatitis C infections who are more likely to have liver fibrosis due to their disease. Examples include serum hyaluronate, matrix metalloproteinase-1 (MMP), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1).
Doctors may also use tests that require calculations, such as an aminotransferase-to-platelet ratio (APRI) or a blood test called FibroSURE that measures six different markers of liver function and puts them into an algorithm before assigning a score. However, a doctor can’t usually determine the stage of liver fibrosis based on these tests.
Ideally, a doctor will diagnose a person with liver fibrosis at an earlier stage when the condition is more treatable. However, because the condition doesn’t usually cause symptoms in earlier stages, doctors don’t usually diagnose the condition earlier.
The most significant complication of liver fibrosis can be liver cirrhosis, or severe scarring that makes the liver so damaged a person will become sick. Usually, this takes a long time to occur, such as over the course of one or two decades.
A person needs their liver to survive because the liver is responsible for filtering harmful substances in the blood and performing many other tasks that are important to the body. Ultimately, if a person’s fibrosis progresses to cirrhosis and liver failure, they can have complications such as:
- ascites (severe buildup of fluid in the abdomen)
- hepatic encephalopathy (buildup of waste products that causes confusion)
- hepatorenal syndrome
- portal hypertension
- variceal bleeding
Each of these conditions can be deadly to a person with liver disease.
According to , liver cirrhosis is one of the leading causes of death worldwide. Therefore, it’s important that a person be diagnosed and treated for liver fibrosis as early as possible before it progresses to liver cirrhosis. Because liver fibrosis doesn’t always cause symptoms, this is hard to do. Sometimes doctors have to consider a person’s risk factors, such as being overweight or a heavy drinker, in diagnosing fibrosis and recommending treatments.