Wednesday 31 July 2019

What is liver fibrosis?


Liver fibrosis occurs when repetitive or long-lasting injury or inflammation causes excessive amounts of scar tissue to build up in the organ. Most types of chronic liver disease can eventually cause fibrosis.
Unlike healthy liver cells, scar tissue cells cannot self-repair or otherwise function. As a result of this, fibrosis can reduce overall liver function and impair the organ's ability to regenerate.
Scar tissue from fibrosis can also block or limit the flow of blood within the liver. This can starve and eventually kill healthy liver cells, creating more scar tissue in the process.
Treatment tends to involve clearing infections, making lifestyle changes, and taking certain medications. This can often reverse the damage of mild to moderate liver fibrosis.
If inflammation continues, possibly because a person has not received treatment, liver fibrosis can develop into more serious liver conditions.
In this article, we will discuss the causes of liver fibrosis, how doctors measure the extent of damage, how symptoms change over time, and the treatments available.

Stages

If a doctor believes that someone has liver fibrosis, they will carefully collect a small tissue sample, or biopsy, from the liver using a large needle.
A pathologist, which is a doctor who specializes in finding the root cause of disease, will then examine the sample under a microscope. They do this to assess the extent and type of damage.
Determining the degree of fibrosis is difficult because pathologists only have a small sample to work with. Other doctors can also assess the same sample in different ways.
Healthcare providers can use several scales to define the stages of fibrosis. These include the Metavir, Ishak, and Batts–Ludwig scales.
These and similar scoring systems take into account the effect that the fibrosis has had on the portal vein, which delivers blood from the intestines to the liver.
Many scales also measure the extent of fibrosis and the location or number of septa, which are fibrous bands of tissue in the biopsy sample.
The Metavir scoring system rates the progression of fibrosis on a scale from A0 to A3:
·         A0: no activity
·         A1: mild activity
·         A2: moderate activity
·         A3: severe activity
The Metavir system also scores the level of fibrosis from F0 to F3:
·         F0: an absence of fibrosis
·         F1: portal fibrosis with no septa
·         F2: portal fibrosis with infrequent septa
·         F3: numerous septa but no cirrhosis
·         F4: cirrhosis
Cirrhosis is scar tissue building up in the liver. This can occur due to unchecked fibrosis. Learn more about cirrhosis here.
The most advanced type of fibrosis someone can have before developing cirrhosis, according to the Metavir system, is stage A3F3.
The Ishak fibrosis scoring system is more complex, and it typically runs from 0 to 6:
·         0: an absence of fibrosis
·         1: an expansion of some portal areas, possibly with short, fibrous septa
·         2: an expansion of most portal areas, possibly with short, fibrous septa
·         3: an expansion of portal areas with sporadic portal-to-portal bridging
·         4: an expansion of portal areas with significant portal-to-portal and portal-to-central bridging
·         5: significant portal-to-portal and portal-to-central bridging with sporadic nodules
·         6: likely or definite cirrhosis
Using the Ishak scale, the most advanced stage of fibrosis a person can have before developing cirrhosis is stage 5.
The Batts–Ludwig scale, common in the United States, is slightly simpler. This scale runs from 0 to 4:
·         0: a lack of fibrosis
·         1: portal fibrosis
·         2: rare portal-to-portal septa
·         3: fibrous septa
·         4: definite or likely cirrhosis
Using the Batts–Ludwig scale, the most advanced stage of fibrosis a person can have before developing cirrhosis is stage 3.
People with fibrosis are usually unaware that they have it. This is because it rarely causes any obvious symptoms.
However, within the liver, fibrosis can:
·         reduce overall function, including the purifying of blood, storing of energy, and clearing of infections
·         limit the organ's ability to regenerate
·         restrict blood flow within the organ
People usually start to experience symptomswhen fibrosis progresses to cirrhosis. These initial symptoms can vary, but some of the most common indicators of early cirrhosis include:
·         a poor appetite
·         feeling weak
·         unexplained exhaustion
·         unexplained weight loss
·         nausea and vomiting
·         discomfort or mild pain in the upper right abdomen
Some common signs of more advanced cirrhosis include:
·         a tendency to bruise or bleed easily
·         edema, or fluid retention in the lower legs, ankles, or feet
·         jaundice, which is a yellowing of the skin and eyes
·         ascites, or abdominal bloating from a buildup of fluid
·         very itchy skin
·         increased sensitivity to medications and their side effects
·         problems with certain cognitive functions, such as memory, concentration, or sleeping
·         a darkening of the urine

Source: Medical News Today

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