HEALTH: Hepatitis B Proteins Cleared without treatment

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Many clear hepatitis B proteins without treatment

 

NEW YORK, Nov 05 (Reuters Health) - Seventy percent of people infected with

the hepatitis B virus (HBV) will clear proteins linked to acute illness from

their bodies after 10 years without drug treatment, according to the results

of a study.

 

The findings suggest that patients who do not clear these

proteins--known as

e-antigens--from their bodies may be good candidates for antiviral

treatment, Dr. Brian J. McMahon of the US Centers for Disease Control and

Prevention's Arctic Investigations Program in Anchorage, Alaska, and

colleagues write in the November 6th issue of the Annals of Internal Medicine.

 

While most people recover within a few months of HBV infection, some can

develop chronic infection, which can lead to cirrhosis (scarring), liver

cancer, liver failure and death. Hepatitis B vaccine is available for all

age groups to prevent HBV infection.

 

Little is known about how frequently people are able to clear infection on

their own and how frequently those with chronic HBV infection go on to

develop liver cancer or liver failure.

 

To investigate, McMahon's team followed 1,536 Alaska Natives with chronic

HBV for several years. All study participants had blood samples taken every

6 months during the study period. Levels of two virus-related proteins

--hepatitis B surface antigens and e-antigens-- were also measured to

gauge the severity of infection.

 

Forty percent of the patients had e-antigens in their blood at the time they

entered the study. Having e-antigen in the blood generally means a person

has " very active liver disease and a lot of virus present, " according to a

patient summary published with the study.

 

After 12 years, the researchers found that two thirds of patients who

initially tested positive for e-antigen cleared the protein from their

bodies and developed antibodies to it. Based on their findings, McMahon and

colleagues estimate that more than 70% of e-antigen-positive people with HBV

infection will clear the antigen from their bodies within 10 years, without

drug treatment.

 

But about 15% of these patients became e-antigen-positive again during the

study period. These patients, as well as older patients, were more

likely to

develop liver cancer, the report indicates.

 

The number of new infections of HBV per year has declined in the US from an

average of 450,000 in the 1980's to about 80,000 in 1999, with the highest

rate of disease occurring in 20- to 49-year-olds, according to the CDC. The

greatest decline has been among children and adolescents, due to routine HBV

vaccination.

 

The agency estimates that 1.25 million Americans are chronically infected

with HBV, of whom 20% to 30% acquired the infection in childhood.

 

SOURCE: Annals of Internal Medicine 2001;135:759-768.