BOSTON — Measuring levels of AIDS antibodies and four other factors can help doctors predict which people infected with the AIDS virus face a high risk of getting the disease within a few months, a study shows.
The research shows that those with low levels of antibodies to the virus in their blood are five times as likely as those with high levels to get the disease within 15 months. This suggests--although it does not prove--that AIDS antibodies may shield people from the disease.
"I suspect that the antibody response early in the course of infection probably is protective," said the study's director, Dr. B. Frank Polk of Johns Hopkins.
If so, this may help explain one of the central mysteries of the AIDS epidemic--why some infected people fall ill while others remain healthy for many years.
More than 29,000 Americans have gotten acquired immune deficiency syndrome, but experts believe several times that number are infected with the AIDS virus.
The new research will run for at least eight years. The information may someday provide clues to stopping whatever triggers an AIDS infection to become AIDS disease.
The study, reported in today's New England Journal of Medicine, began with 1,835 homosexual men who were infected with the AIDS virus but did not have AIDS. After 15 months of follow-up, 59 had gotten the disease. The researchers looked to see how those who fell ill and those who stayed healthy had differed at the study's outset.
Besides low AIDS antibody levels, researchers found that the infected people were significantly more likely to get AIDS if they had low levels of white blood cells called T helper cells, high levels of another variety of blood cells called T suppressor cells, large amounts of antibody to the cytomegalovirus or could recall having sex with someone who had gotten AIDS.
Virus Kills Cells
The AIDS virus infects helper T cells, which orchestrate the body's defenses against disease. As the virus spreads, it kills these cells.
Cytomegalovirus is a common virus to which most adults have been exposed with little ill effect. In AIDS patients, it can cause several ailments.
Polk said measuring the five factors can help doctors predict the likelihood that infected people will soon get AIDS, but he noted that nothing can be done to stop the disease.
"The good news is that you can probably be a better prognosticator as a physician," he said. "The bad news is, so what? What can the patient do except get his affairs in order?"