HERE'S HEALTH

Can an arthritis drug protect the livers of alcoholics?

WITH the help of some hard-drinking mice, researchers have shown how
alcohol abuse damages the liver. What's more, they say a drug already
on the market could stave off such damage.

Alcohol abuse can cause inflammation of the liver, or hepatitis, which
eventually leads to scarring, or cirrhosis. Alcoholics with severe
hepatitis have higher levels of an inflammatory protein called tumour
necrosis factor alpha (TNF-alpha) than alcoholics without liver
disease. In the liver, TNF-alpha is mainly produced by cells called
Kupffer cells, and animal experiments show that selectively destroying
these cells can prevent alcohol-induced damage.

Now a team lead by Ronald Thurman of the University of North Carolina
at Chapel Hill has found even more striking evidence that TNF-alpha
plays a central role in alcoholinduced liver disease. The researchers
genetically engineered mice that lacked the receptor for TNF-alpha.
They gave the modified mice alcohol for four weeks and then compared
them with normal mice that drank the same amount of alcohol.

The mice without TNF-alpha receptors had just a seventh as much liver
damage as the normal mice (Gastroenterology, vol 117, p 942). "When we
took out just one protein, we blocked almost all the injury," says
Thurman. "We didn't expect to see so much protection." His group is
now repeating the experiment over a longer period to see if the
modified mice also escape cirrhosis.

"It definitely increases our knowledge of alcohol-induced liver
damage," says Samir Zakhari of the National Institute on Alcohol Abuse
and Alcoholism, near Washington DC. He says that other factors such as
the formation of free radicals probably contribute to liver damage,
but that TNF-alpha must be a major player.

Thurman says some people with arthritis take a drug called Enbrel,
which reduces inflammation by mopping up TNF-alpha. He hopes to test
this drug in alcoholics with hepatitis.