Cirrhosis

Cirrhosis is a chronic disease of the liver in which liver tissue is replaced by connective tissue, resulting in the loss of liver function. Cirrhosis is caused by damage from toxins (including alcohol), metabolic problems, chronic viral hepatitis or other causes. Cirrhosis is sometimes referred to by its obsolete eponym Laennec's cirrhosis after René Laënnec. Cirrhosis is irreversible but treatment of the causative disease will slow or even halt the damage.

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.

Related Topics:
Albumin - Clotting factors - Complement - Vitamin A - Lipid - Carbohydrate

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

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. Iredale (2003) summarises the pivotal role of 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 and obstructs blood flow in the circulation. In addition, it secretes TGF-β1, which leads to a fibrotic response and proliferation of connective tissue. Furthermore, it disturbs the balance between matrix metalloproteinases and the naturally occurring inhibitors (TIMP 1 and 2), leading to matrix breakdown and replacement by connective tissue-secreted matrix.

Related Topics:
Parenchyma - Stellate cell - Vitamin A - TGF-β₁ - Connective tissue - Matrix metalloproteinase - Matrix

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The fibrous tissue forms nodes, which eventually replace the entire liver architecture, leading to decreased blood flow throughout. The spleen becomes congested, which leads to hypersplenism and increased sequestration of platelets. Portal hypertension is responsible for most severe complications of cirrhosis.

Related Topics:
Spleen - Hypersplenism - Platelet

~ ~ ~ ~ ~ ~ ~ ~ ~ ~