Liver transplants have come of age and should be performed more often, but not to replace livers of alcoholics and drug abusers, a panel sponsored by the National Institutes of Health recommended yesterday.

The panel's findings could help clear the way for government and private insurers to pay for liver transplants, which cost in the range of $100,000.

According to the American Liver Foundation, liver disease kills about 50,000 Americans a year, making it the fourth leading cause of death among patients aged 15 to 65.

The panel was established by the NIH to develop a "consensus document" that describes the state of the art as seen by the best practitioners in the field. The 13 doctors and professionals issued their report at the end of a two-day meeting here.

The panel declared that the risky and difficult liver transplant technique is a valid method of therapy that improves on conventional therapy in some cases. It recommended that the technique, now still relatively infrequent, be used more often.

About 75 to 100 liver transplants are performed annually in the United States, and the number is expected to increase to hundreds or thousands a year as surgeons and hospital staffs learn the techniques.

The panel specified types of patients who normally should and should not be candidates to receive livers from the comparatively few available donors.

It virtually eliminated persons afflicted with the most common forms of fatal liver disease in America: alcohol-related cirrhosis and alcoholic hepatitis. It also said victims of chronic hepatitis, such as drug abusers, are poor transplant candidates.

In both the alcohol-related diseases and chronic hepatitis, the transplant often has proved useless because the disease recurs in the newly implanted liver, according to Rudi Schmid, chairman of the NIH panel and a professor at the University of California at San Francisco.

But the panel added that patients "judged likely to abstain from alcohol" might be considered as candidates. Schmid said that suggested standards ranged from six months to two years of proven abstinence but that the panel would leave the decision to doctors.

Another set of patients with very low survival rates--about 12 percent three years after transplantation--are those with terminal liver cancer. Stray cancer cells often remain after the transplant and attack the new liver.

On the other hand, the panel found that infants with a liver duct blockage called extrahepatic biliary atresia have relatively good survival rates after transplants and therefore are good candidates, as are patients who have cirrhosis (a scarring of the liver) but are not alcoholic.

Among other promising cases for transplants are persons with inborn liver defects that cause a fatal inability to produce necessary body chemicals, to filter poisons from the system or to drain properly as blood passes through the liver.

At present, transplants of only kidneys and corneas are designated routine medical procedures eligible for payment under government and private medical payment plans. Transplants of the heart, liver and pancreas still are considered "experimental" rather than "therapeutic."

The Public Health Service is expected to recommend soon whether livers should become the third human organ to be approved for widely available, insurer-paid transplants. The NIH panel's report is expected to have significant influence on the Public Health Service's decision, Schmid said.

Liver transplants normally are not considered until the patient is near death, so even survival rates less than 50 percent may be counted as positive, doctors said.

But the panel said the survival rate has increased significantly in the past two or three years. The chief reason appears to be a new drug, Cyclosporin, which prevents the body from rejecting transplanted tissue.

The survival rate, excluding cancer patients, one year after transplant was 54 percent for those who received Cyclosporin, compared with 29 percent for those who had not. After three years, the rates were 49 percent for Cyclosporin patients and 20 percent for those without.

At the same time the NIH panel was delivering its results, 7-month-old Julie Bohrer, the youngest child to receive a liver transplant, was "doing very well" in critical but stable condition yesterday, a spokesman for University of Minnesota Hospitals said.