Thursday, August 23, 2012
New non-contagious AIDS-like disease found in Asia
Even as the promise of an AIDS vaccine seems finally within humanity's reach, researchers in the United States have discovered a new disease —as-yet unnamed, but fortunately non-contagious— with very AIDS-like symptoms.
AIDS —or acquired immune deficiency syndrome— results from the human immunodeficiency virus (HIV), which completely disables its host's natural defenses against infection. In the Philippines alone, as of June 2012, there were 295 reported HIV-positive cases, 16 of which were AIDS cases,according to the National Epidemiology Center's latest HIV Surveillance Report.
However, unlike HIV, the newly-discovered immunodeficiency disease does not spread through a virus, nor is it inherited, said Dr. Sarah Browne of the US National Institute of Allergy and Infectious Diseases.
Differences from HIV
HIV attacks and destroys T-cells, the main defense of the bodies against germs. In contrast, the new disease does not affect those cells but in stead causes "a different kind of damage," said Browne.
Her study of 206 people from Taiwan and Thailand found that most of those infected with the disease make substances called "autoantibodies" that attack the body's own tissues instead of fighting off invading germs.
The autoantibodies found by Browne's study block interferon-gamma, a chemical signal that helps the body fight off infections. When the chemical signal is blocked, the person becomes vulnerable to fungal infections, viruses, parasites, and other bacteria —just as in an AIDS patient.
“Fundamentally, we do not know what’s causing them to make these antibodies,” Browne said.
Browne helped spearhead the study together with other researchers in Thailand and Taiwan, where most of the reported cases have been found since 2004. The study was published in Aug. 23 issue of New England Journal of Medicine.
While the institute is yet to determine what triggers the disease, they found that it does not seem to be contagious.
Dr. Dennis Maki, infectious disease specialist at the University of Wisconsin in Madison said, “This is absolutely fascinating. I’ve seen probably at least three patients in the last 10 years or so (who might have had the disease).”
Maki also said that it is still possible that an infection could trigger the disease, even if it does not seem to spread person-to-person.
The disease does not run in families, and develops at around the age of 50. Browne said that these characteristics hint that it is unlikely that a single gene is responsible for the disease.
Browne also said that an unspecified number of patients died of "overwhelming infections".
Kim Nguyen, 62, is a seamstress from Vietnam who has lived in Tennessee, USA since 1975. In 2009, she sought help for a persistent fever, infections throughout her bones and other symptoms in 2009. She said she had been sick on and off for several years and had visited Vietnam in 1995, and again early in 2009.
Family physician at Jackson Clinic in Tennessee Dr. Carlton Hays said that he first thought Nguyen has tuberculosis but realized that she has a different kind of infection,"She was wasting away from this systemic infection."
“She’s a small woman to begin with, but when I first saw her, her weight was 91 pounds, and she lost down to 69 pounds," said Hays.
Nguyen was later on referred to specialists at the National Institutes of Health (NIH) who had been tracking similar cases. She spent almost a year at an NIH hospital in Maryland, and is there now for monitoring and treatment.
“I feel great now,” Nguyen said in an interview with Associated Press on Aug. 22.
When she was sick before she said she felt dizzy, headaches, and could not eat anything.
Multiple treatment approaches
Doctors in NIH have tried a variety of approaches to treat those affected with this new disease. They said that antibiotics are not always effective. Some have even resorted to using a cancer drug that helps stop production of antibodies. The disease tends to quiet down in some patients once the infections are tamed. However, researchers said that faulty immune system is "likely a chronic condition."
As almost all the patients so far have been Asian or Asian-born people living elsewhere suggests that something in the environment, and genetic factors may trigger the disease, researchers said.
“We know there are many others out there,” including cases mistaken as tuberculosis, Browne said.
The first cases of the new disease were found in 2004. — TJD, GMA News