Genes That May Affect AIDS Onset Found

Scientists have found genes that may explain why some people infected with HIV quickly develop AIDS symptoms while others with the virus may live for years.

The discovery has no immediate benefit for HIV patients but increases understanding about how the virus attacks the body, said Mary Carrington, one of the researchers involved in the study.

Such understanding could eventually help researchers design vaccines or other drugs to treat HIV, she said. In a genetic study of about 500 people infected with the human immunodeficiency virus, the researchers at the National Cancer Institute found that differences in the inherited pattern of what are called HLA Class I genes determined who became sickest the soonest and who was able to hold off the disease progression. A report on the study appears today in the journal Science.

Carrington said Thursday that there are three different HLA Class I genes. People inherit two copies of each.

HLA Class I genes are part of the immune system. Their job is to identify cells that are infected with the virus and to leave a signal molecule on the surface of the infected cell. Another part of the immune system, the cytotoxic T-cell, will kill cells marked by the signal molecule.