Baffling Resistance to SARS [AIDS patients may be resistant]

Newsday ^ | April 29, 2003 | Laurie Garrett

[CobaltBlue]

Beijing -- A small but potentially intriguing clue has emerged in the SARS fight, even as China's epidemic continues to spiral.

Amid the mounting toll, Newsday learned that a select population in Guangzhou, the southern Chinese city where the epidemic apparently began in November, appears to have resisted infection. At the peak of the outbreak there, in January and February, patients with the then-mystery illness were kept on the second floor of one hospital. The floor was already in use as an AIDS ward.

Guangzhou authorities divided the floor of People's Hospital No. 8 in half, putting SARS patients on one side of the elevator bank, and AIDS patients on the other. Health care workers walked back and forth between the two sides of the floor, and some of those doctors and nurses contracted SARS.

Yet not one of the several dozen AIDS patients or their visitors, some of whom were also HIV positive, developed the disease.

Dr. Cheng Feng of the China/UK HIV/AIDS Project said he, too, was aware of the phenomenon. He wondered whether the drugs the AIDS patients were receiving for HIV control might be blocking a SARS infection. A similar notion was mentioned by Dr. Yuen Kowk-yung of the University of Hong Kong. With New York's Dr. David Ho, of the Aaron Diamond AIDS Research Laboratory, Yuen is exploring the AIDS apothecary for an effective SARS treatment.

But the puzzle may be deeper. That's because the most effective anti-HIV drugs -- a class called protease inhibitors -- are not available to Guangzhou patients, according to an HIV outpatient and activist who asked to be identified only as Thomas. Few Chinese patients have access to any but the cheapest, least effective of the anti-HIV drugs, Thomas said, which target a chemical that is not even present on the coronavirus that's been identified as causing SARS.

Copyright © 2003, Newsday, Inc.

[CobaltBlue]

Comment on above article by Dave Sonntag on Sarswatch blog:

>>This is an extremely important point. Yesterday's Washington Post (http://www.washingtonpost.com/wp-dyn/articles/A50579- 2003Apr28.html) described suggestions that infants and young children do not seem to be as severely affected by SARS. Do these stories have anything in common with suspicion that SARS may also be more severely impacting Asian countries?

Distribution of a genetic polymorphism (variant R131/H131 to be specific) of the Fcgamma receptor (CD32) may have implications for disease susceptibility if cirulating IgG2 is involved. It turns out that the spike glycoprotein of some coronaviruses might in fact have such activity.

The H131/R131 polymorphism is known to be an important outcome predictor in other diseases like bacterial respiratory infections, meningococcal infection, malaria, Dengue Hemorrhagic Fever, SLE, and Kaposi sarcoma. The H131 version has a high affinity for IgG2, while the R131 version of the receptor only binds IgG2 weakly.

More importantly, the H131 version is present in 61% of ethnic Chinese, 50% of Japanese, while only 23% of Caucasians or Asian Indians have the high affinity H131 CD32 receptor.

This suggests as a working hypothesis that SARS may provoke a cascade, via CD32-binding and downstream activation of NF-kB and other inflammatory pathways. Immune suppression could reduce the number of circulating CD32+ cells. Certainly infants have lower levels and activity of CD32+ cells, since it would be counterproductive to circulating maternal antibody levels.


Posted by: Dave Sonntag on Apr 30, 03 | 4:45 am<<
http://www.sarswatch.org/comments.php?id=218_0_1_0_C

[Dog Gone]

The answer may be rather simple. In SARS victims, the damage is done by your own immune system attacking the virus. Treatment is with steroids to inhibit your immune response.

That's already in place in AIDS patients.

[CobaltBlue]

If so, it stands to reason that other immune-compromised and immune-suppressed patients should have similar responses.

This would include:

1) People taking immune-suppressants for autoimmune diseases;
2) People taking cancer chemotherapy drugs which suppress the immune system;
3) People taking immune-suppressants for organ transplants;
4) People with naturally lack of immune response e.g., "boy in the bubble" types.

[Jim Noble]

Not necessarily.

I have never seen a case of severe Influenza A in an HIV-infected person. Presumably, since its T-cells that wreck the lung in fatal influenza, the HIV-related T cell defect is protective in this case.

Very few forms of immunosuppression due to drugs or other diseases mimic HIV infection. Immunosuppression after transplants is somewhat similar.

In any event, if these observations are true, they suggest that T cells are playing a role in fatal SARS.

[I'll be your Huckleberry]

Quote from the full article:

SARS so far has presented scientists with a number of perplexing aspects.

Some scientists speculate that the virus doesn't actually kill human cells -- that the immune system's overreaction actually precipitates the destruction of cells of the lung and other parts of the body, precipitating the acute pneumonia that is the disease' hallmark.

In theory, they say, death may be the result of an aberrant or overly sensitive immune response. If that is proved correct, it's possible that HIV patients may actually be at lower risk for SARS precisely because they lack strong immune responses.

(Some scientists----Hmmmm, we may know one of these)

I remember what you are talking about. However, I don't think she said it was not a virus. She basically said she believed we were looking at an immune system destroyer, and we were seeing remnants of opportunistic infections. This what not how she stated it but it was exactly how I phrased the question back to her and she said yes, that was what she meant.

20 posted on 04/22/2003 8:25 PM PDT by riri

I am going to look back and see if I can find MA's exact words.

[Cobra Scott]

What about marijuana's reported effects on the immune system?

I expect this will eventually be hyped by the antiWOD crowd. Of course they'll first actually have to admit that it does indeed suppress the immune system, LOL!

[Dog Gone]

If the lack of a normal immune system prevents the symptoms of SARS, it would still be essential to determine whether the patient has the SARS virus. It may not be doing the expected damage, but it might make that patient a very deadly carrier of the disease.

I would certainly want to test these unaffected HIV patients for the presence of the coronavirus.

[CathyRyan]

OK, it is official I am confused.

Can someone type real slow so I can understand this?

You are saying that while a person is infected with sars it acts like AIDS to compromise the immune system?

That is why an AIDS patient do not get sars is because their immune system is already trashed?

Does a person's immune system stay trashed after recovery from sars?

Does sars attack the immune system or does the immune system over attack sars?

If sars attacks the immune system and over powers it then an opportunistic disease can come in or if sars is over powered by the immune system then the person can die?

Why wouldn’t everyone who get sars be dead either from the over reaction of the immune system or from the opportunistic disease?

[riri]

In any event, if these observations are true, they suggest that T cells are playing a role in fatal SARS

As a layman, I was pretty certain they would fit into this puzzle somehow.

[I'll be your Huckleberry]

Cathy I do not have a clue, I am a Board Certified casino lizard by trade and I only know what I read.

This caught my eye because a few of us were discussing this exact same thing a few days ago. How MA had said roughly the same thing over a month ago before she split.

If I remember correctly this bit of speculation is what caused you-know-who to have such a hissy fit and be so rude to MA.

[riri]

Why wouldn?t everyone who get sars be dead either from the over reaction of the immune system or from the opportunistic disease?

I read a post yesterday that said victims in Hong Kong are relapsing. I have not seen this anywhere, have you?

[riri]

I know absolutely nothing about microbiology (except what I have learned in the past month). Instinctively, I had a feeling we were looking at something like this.

Yeesh, what is the best course of action? Start a heroin addiction, contract HIV to prolong your life and you won't care about SARS anymore anyway...?!!

[CathyRyan]

I have heard if you say the name three times it will appear. ;)

[CathyRyan]

http://www.ananova.com/news/story/sm_775602.html

[xkaydet65]

Good observation. I've also heard it alleged that the presence of some viruses in the system can act as an inhibitor against infection by other viruses. Though I think your scenario most likely, I think all avanues of the effects of viral infection should be investigated.

[riri]

Thanks, I found it after I posted the question to you. Well, I was feeling a bit optimistic for a few days...However, it does seem to appear the relapses are not as severe.

IMO, we need to take that 15 billion dollars we are giving to Africa and give it to the best biotech companies here in the states to work on this, yesterday.

[I'll be your Huckleberry]

LOL,

I think I will pass on that suggestion. I must depend on my morning bloody mary's and sunset martini's and of course the late night brandy separators (one of Nevada's great traditions) for protection.

This has been a steep learning curve for me too. I have waaaaay
too much information about these bugs than necessary from my Freeper habit of reading all this news.

However after a shower and a latte I will lose myself in snow covered mountains, gambling and sin. Not to mention the lovely senior citizens who remove their oxygen masks to smoke one more cancer stick.

[Route66]

'I read a post yesterday that said victims in Hong Kong are relapsing. I have not seen this anywhere, have you?'
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.
I just saw this go by on the FOX news ticker. It says some patients in China previously declared recovered are having relapses. I know this can happen with colds and flu so I assume there will be a certain amount of this with this syndrome too.

I do think however that we are yet in the early stages of discovery concerning what actual 'recovery' means with this disease. That is worrysome. There are still too many things we don't know about the course of this disease and what we can expect to see among the survivors.

[Dog Gone]

Hong Kong, Apr 30: Some SARS patients in Hong Kong have suffered relapses after being listed as recovered and discharged from hospitals, according to health officials who said today they were investigating the cases.

A hospital authority spokeswoman said on condition of anonymity that less than 10 patients have relapsed. Officials were ``very concerned'' about the cases and were studying them.

The number of new cases reported each day recently has been staying in the teens, which some experts say is encouraging. Bigger daily totals had been reported earlier this month.

Another 32 people have recovered and been discharged, or a total of 791, health officials told a news conference.

Health department spokesman Jimmy Lee earlier confirmed there had been a few relapses, but he declined to provide numbers or details. Lee confirmed news reports that one patient had fallen ill again and was readmitted to a hospital last Thursday after being discharged three days earlier.

University of Hong Kong microbiologist Malik Peiris said although relapses are ``not a good thing,'' they weren't surprising given how little is known about the virus that causes SARS.

``We are still learning about the SARS disease so we cannot say it's not possible,'' Peiris said. He predicted patients with relapses can recover fully, based on experience with other diseases from coronaviruses, a strain of which experts believe causes SARS.