[美國NIH自2004年以來收集超過一百多名病患，有免疫不全，而引起各種伺機性感染，如同AIDS，卻又不是因為HIV引起，也不是人對人感染所引起，多半是50歲以上。九成以上病患血中有對可以觸動體內免疫反應的 interferon-gamma 的自我抗體(autoantibody)。這些病患都是亞裔人，有些是住在美國，家族間不會感染，因此可能是和基因有關。顯然這是新出現的免疫不全疾病，暫時被稱為 Adult Onset Immunnodeficiency Syndrome。最新得到的訊息如下]
Date: Thu, 23 Aug 2012 18:21:21 -0400 (EDT)
From: ProMED-mail <promed@promed.isid.harvard.edu>
Subject: PRO/EDR> Adult-onset immunodeficiency
syndrome - Asian patients, not HIV
ADULT-ONSET IMMUNODEFICIENCY SYNDROME - ASIAN
PATIENTS, NOT HIV
***************************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: Thu 22 Aug 2012
Source: Associated Pres [edited]
<http://hosted.ap.org/dynamic/stories/U/US_MED_MYSTERY_DISEASE?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2012-08-22-18-04-18>
New AIDS-like
disease in Asians, not contagious
- -----------------------------------------------
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 is in Thursday's [22 Aug
2012] New England Journal of Medicine [see below]. "This is absolutely
fascinating. I've seen probably at least 3
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 in
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.
A 62-year-old
seamstress from Viet Nam 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 had been sick off and on for several years and had visited
Viet Nam in 1995 and again in early 2009.
"She was wasting away from
this systemic infection" that at 1st seemed like tuberculosis but
wasn't,
said Dr. Carlton Hays Jr., a family physician at the Jackson
Clinic in Jackson, Tenn. "She's a small woman
to begin with, but when
I 1st saw her, her weight was 91 pounds, and she
lost down to 69
pounds."
This patient 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 [21 Aug
2012]. But when
she was sick, "I felt dizzy, headaches, almost fell
down," she said. "I could not eat
anything."
AIDS is a specific disease, and it stands for
acquired immune
deficiency syndrome. That means the immune system
becomes impaired
during someone's lifetime, rather than from
inherited gene defects
like the "bubble babies" who are born
unable to fight off germs. The
virus that causes AIDS -- HIV [human
immunodeficiency virus) --
destroys T-cells, key soldiers of the immune
system that fight germs.
The new disease doesn't affect those cells, but
causes a different
kind of damage. 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.
Blocking that signal leaves people like those with
AIDS -- vulnerable
to viruses, fungal infections and parasites, but
especially
mycobacteria, a group of germs that can cause
severe lung damage.
Researchers are calling this new disease an "adult-onset"
immunodeficiency syndrome because it develops later in life and they
don't know why or how. "Fundamentally, we do
not know what's causing
them to make these antibodies," Browne said.
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 quietens in
some patients once
the infections are tamed, but the faulty immune
system is likely a
chronic condition, researchers believe. The fact
that nearly all the
patients so far have been Asian or Asian-born
people living elsewhere
suggests that genetic factors and something in the
environment such as
an infection may trigger the disease, researchers conclude. The 1st
cases turned up in 2004 and Browne's study
enrolled about 100 people
in 6 months. "We know there are many others out
there," including many
cases mistaken as tuberculosis in some countries,
she said.
[Byline: Marilynn Marchione]
- --
Communicated by:
ProMED-mail
<promed@promedmail.org>
[It is assumed the preceding press statement is
based on the paper
titled: Adult-Onset Immunodeficiency in Thailand and
Taiwan. By Sarah
K. Browne and other, published in the current
issue of the New England
Journal of Medicine (N Engl J Med 2012;
367:725-734 August 23, 2012;
<http://www.nejm.org/doi/full/10.1056/NEJMoa1111160>). The authors'
summary follows.
Background
- ----------
Autoantibodies against interferon-gamma are
associated with severe
disseminated opportunistic infection, but their
importance and
prevalence are unknown.
Methods
- -----------
We enrolled 203 persons from sites in Thailand
and Taiwan in 5 groups:
52 patients with disseminated, rapidly or slowly
growing,
nontuberculous mycobacterial infection (group 1); 45 patients with
another opportunistic infection, with or without
nontuberculous
mycobacterial infection (group 2); 9 patients with disseminated
tuberculosis (group 3); 49 patients with pulmonary tuberculosis (group
4); and 48 healthy controls (group 5).
Clinical histories were
recorded, and blood specimens were obtained.
Results
- ------
Patients in groups 1 and 2 had CD4+ T-lymphocyte
counts that were
similar to those in patients in groups 4 and 5,
and they were not
infected with the human immunodeficiency virus
(HIV). Washed cells
obtained from patients in groups 1 and 2 had
intact cytokine
production and a response to cytokine stimulation.
In contrast, plasma
obtained from these patients inhibited the
activity of
interferon-gamma in normal cells. High-titer
anti-interferon-gamma
autoantibodies were detected in 81 percent of
patients in group 1, 96
percent of patients in group 2, 11 percent of
patients in group 3, 2
percent of patients in group 4, and 2 percent of
controls (group 5).
40 other anticytokine autoantibodies were assayed.
One patient with
cryptococcal meningitis had autoantibodies only
against
granulocyte-macrophage colony-stimulating factor.
No other
anticytokine autoantibodies or genetic defects
correlated with
infections. There was no familial clustering.
Conclusions
- ----------
Neutralizing anti-interferon-gamma autoantibodies
were detected in 88
percent of Asian adults with multiple
opportunistic infections and
were associated with an adult-onset
immunodeficiency akin to that of
advanced HIV infection.
The adult-onset immunodeficiency syndrome,
mediated by the production
of anti gamma-interferon antibodies, does not
appear to be contagious
and the condition develops around age 50 on
average but does not run
in families, which makes it unlikely that a single
gene is
responsible, The prevalence of this condition in
Asian people, though
not necessarily resident in Asia, implies a
genetic origin rather than
a cryptic infectious agent. But anything is
possible. - Mod.CP]
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