Cirrhosis of the Liver

Cirrhosis of the Liver

Introduction

Cirrhosis is scarring of the liver that involves the formation of fibrous (scar) tissue associated with the destruction of the normal architecture of the liver. It is the result of long-standing injury most commonly due to alcohol in excess but there are a number of other important causes. The destruction of the normal architecture and the loss of liver cells prevents the liver from functioning normally. It plays an important part in digestion of food but it also has a major role in metabolising drugs and making proteins, including those that help the blood to clot (Sundaram & Shaikh, 2009).

Cirrhosis is a serious condition. Survival five years after diagnosis is dependent on the underlying cause of the cirrhosis. The severity of the liver disease can be assessed by scoring system - the most commonly used is the Child's-Pugh classification. The outlook is worse if the cause is alcohol and the patient continues to drink.

Discussion

Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules (lumps that occur as a result of a process in which damaged tissue is regenerated. leading to loss of liver function. Cirrhosis is most commonly caused by alcoholism, hepatitis B and hepatitis C, and fatty liver disease, but has many other possible causes. Some cases are idiopathic (i.e., of unknown cause). Ascites (fluid retention in the abdominal cavity) is the most common complication of cirrhosis, and is associated with a poor quality of life, increased risk of infection, and a poor long-term outcome. Other potentially life-threatening complications are hepatic encephalopathy (confusion and coma) and bleeding from esophageal varices. Cirrhosis is generally irreversible, and treatment usually focuses on preventing progression and complications. In advanced stages of cirrhosis the only option is a liver transplant.

Pathophysiology

The liver plays a vital role in synthesis of proteins (e.g., albumin, clotting factors and complement), detoxification and storage (e.g., vitamin A). In addition, it participates in the metabolism of lipids and carbohydrates. Cirrhosis is often preceded by hepatitis and fatty liver (steatosis), independent of the cause. If the cause is removed at this stage, the changes are still fully reversible.

The pathological hallmark of cirrhosis is the development of scar tissue that replaces normal parenchyma, blocking the portal flow of blood through the organ and disturbing normal function. Recent research shows the pivotal role of the stellate cell, a cell type that normally stores vitamin A, in the development of cirrhosis. Damage to the hepatic parenchyma leads to activation of the stellate cell, which becomes contractile (called myofibroblast) and obstructs blood flow in the circulation. In addition, it secretes TGF-ß1, which leads to a fibrotic response and proliferation of connective tissue. Furthermore, it secretes TIMP 1 and 2, naturally occurring inhibitors of matrix metalloproteinases, which prevents them from breaking down fibrotic material in the extracellular matrix (Sundaram & Shaikh, 2009).

What are the causes of the inflammation that leads to cirrhosis of the liver?

Alcohol excess: the rate of cirrhosis in ...