Acute Liver Injury Essay

There are many different causes of liver damage. These can be grouped into various categories depending on the timing of the insult and the types of cells most severely affected. As the nature of injury often dictates patient outcome, these patterns of injury have important clinical implications.

Acute versus chronic: Acute liver injury is a common clinical problem. In the most severe cases, acute injury results in overwhelming hepatocyte loss, a clinical condition known as acute liver failure. More frequently, however, acute injuries are self-limiting (assuming that the underlying pathophysiological process resolves) and thus generally do not result in long-term damage. By contrast, chronic liver injuries occur over years, leading to liver dysfunction through the development of fibrosis and/or cirrhosis. Although

Thus, foreign substances undergo so-called first-pass metabolism before they reach other organs in the body. Some hepatotoxins, including carbon tetrachloride (CCl4) and many commonly used drugs, directly cause damage to hepatocytes. However, other toxins become toxic only as a result of enzymatic modification by the liver’s detoxification machinery—the Cytochrome P450 enzymes. For example, acetaminophen (Tylenol) has no toxic properties by itself but becomes noxious upon conversion to the mitochondrial toxin NAPQI (N-acetyl-p-benzoquinone imine) through the activity of the P4502E1 enzyme (14). Toxins can cause injury to hepatocytes, BECs, or both. Cytochrome P450 enzymes are most abundant in zone 3 hepatocytes, accounting for the higher rate of drug toxicity in that portion of the lobule. Toxins can cause either acute or chronic damage, with the most common offenders being alcohol, acetaminophen, galactosamine, CCl4, antibiotics, and nonsteroidal anti-inflammatory