WEDNESDAY, Aug. 22 (HealthDay News) -- Investigators say they've identified an emerging immune-deficiency syndrome that is killing or sickening people in East Asia.
Although human immunodeficiency virus (HIV) is not linked to the illness, the illnesses appear similar to what people with HIV often get, say the team from the U.S. National Institutes of Health.
The new syndrome, which does not seem to pass from person to person, involves an immune-system antibody that blocks a molecule critical to fighting off infections and auto-immune diseases.
The antibody works against a common protective molecule called interferon-gamma (IFN-gamma), triggering immunodeficiency in some adults, the research team said.
People with the syndrome seem especially susceptible to infections caused by what are called opportunistic microbes, which can lie dormant in the body for years but are activated and multiply when the body's immune system is weakened. They're more likely to get diseases such as nontuberculous mycobacteria (NTM), a rare cousin to tuberculosis that can cause severe lung disease.
NTM and other opportunistic diseases often are seen in people with immune deficiency, but are rare in those with healthy immune systems. Researchers in countries such as Taiwan and Thailand have recently reported several cases of NTM in people with no history of immune-system problems.
"It's too soon to know the cause," said Dr. Sarah Browne, lead author of the study, which was published Aug. 23 in the New England Journal of Medicine. "The problem could be related to something genetic in people of Asian descent or it could be tied to environmental factors, but it's too early to know."
Browne, who is assistant clinical investigator at the U.S. National Institute of Allergy and Infectious Disease in Bethesda, Md., said although some people with the problem become extrem
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