Scientists puzzle over AIDS-like disease
- August 25, 2012 - 4:15 PM
Researchers have identified a mysterious new disease that has left scores of people in Asia and some in the United States with AIDS-like symptoms even though they are not infected with HIV.
The patients' immune systems become damaged, leaving them unable to fend off germs as healthy people do. What triggers this isn't known, but the disease does not seem to be contagious.
This is another kind of acquired immune deficiency that is not inherited and occurs in adults, but doesn't spread the way AIDS does through a virus, said Dr. Sarah Browne, a scientist at the National Institute of Allergy and Infectious Diseases.
She helped lead the study with researchers in Thailand and Taiwan where most of the cases have been found since 2004. Their report was in Thursday's New England Journal of Medicine.
"This is absolutely fascinating. I've seen probably at least three patients in the last 10 years or so" who might have had this, said Dr. Dennis Maki, an infectious disease specialist at the University of Wisconsin-Madison.
It's still possible that an infection of some sort could trigger the disease, even though the disease itself doesn't seem to spread person-to-person, he said.
The disease develops around age 50 on average but does not run in families, which makes it unlikely that a single gene is responsible, Browne said. Some patients have died of overwhelming infections, including some Asians now living in the U.S., although Browne could not estimate how many.
Kim Nguyen, 62, a seamstress from Vietnam who has lived in Tennessee since 1975, was gravely ill when she sought help for a persistent fever, infections throughout her bones and other bizarre symptoms in 2009.
"She was wasting away from this systemic infection" that at first seemed like tuberculosis but wasn't, said Dr. Carlton Hays Jr., a family physician at the Jackson Clinic in Jackson, Tenn.
Nguyen (pronounced "when") was referred to specialists at the National Institutes of Health who had been tracking similar cases. She spent nearly a year at an NIH hospital in Bethesda, Md., and is there now for monitoring and further treatment. "I feel great now," she said Wednesday.
Browne's study of more than 200 people in Taiwan and Thailand found that most of those with the disease make substances called autoantibodies that block interferon-gamma, a chemical signal that helps the body clear infections.
Antibiotics aren't always effective, so doctors have tried a variety of other approaches, including a cancer drug that helps suppress production of antibodies. The disease quiets in some patients once the infections are tamed, but the faulty immune system is likely a chronic condition, researchers believe.
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