2% of CD4s in blood, 98% in mucosal tissues vagina, airways, esp. the gut

[bimazek]

New research suggests HIV treatment focus on guts
www.chinaview.cn 2006-12-17 04:29:14

    LONDON, Dec. 16 (Xinhua) -- HIV deals a body blow to the immune system almost immediately after infection by destroying key cells in the gut lining, new research findings show.

    HIV attacks CD4 cells, known as "helper" T-cells, which help coordinate immune responses. In the blood of infected people, there is a steady fight between viral replication and the production of new CD4 cells to replace those that are lost to the virus. If left untreated, HIV eventually wins this battle, and the immune system collapses.

    New research have shown that only about 2 percent of CD4 cells circulate in the blood, and the vast majority of CD4 cells, some 98 percent, are in mucosal tissues, such as those lining the vagina, airways and especially the gut - possibly because pathogens typically enter the body through such tissues, according to the latest issue of the New Scientist published on Saturday.

    The number of CD4 cells in the gut lining plummets by up to 60 percent within the first few weeks of infection.

    Researchers led by Martin Markowitz of the Aaron Diamond AIDS Research Center in New York are picking apart the mechanisms by which HIV wreaks havoc in the gut, the report said.

    The virus not only kills gut CD4 cells directly but also gets the immune system to turn on itself: some CD4 cells self-destruct and others seem to be killed by other T-cells, which the researchers believe is linked to the way HIV activates the immune system abnormally.

    This may explain why highly active anti-retroviral therapy (HAART), most successful treatment for HIV now, does not fix all the damage that HIV causes, even in people who are treated very early after being infected.

    The virus hits immune cells in mucosal tissues hard and fast, usually before treatment with HAART even starts. Despite being put on drugs within about three weeks, 70 percent of Markowitz's patients lost more than half of the CD4 cells in their lower gut, the report said.

    The damage may also trigger further harmful immune activation throughout the body, said Daniel Douek at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, whose work suggests that damage to the gut enables molecules including lipopolysaccharides which are a component of bacterial cell walls and stimulate the immune system, from microbes in the gut to enter the bloodstream, the New Scientist said

laymens point of view...

questions
does this mean that on haart, hiv is 49 times more active in the gut than in the blood?
what treatments are possible for the chronic inflamation of gut mucosal tissue that is infected even on haart?
does taking an anti inflamitory as suggested at end of article about gut being prductively infected make sense? would it help in any way?
since the gut lining replaces itself very fast, every 3 days?, is it possible that that is why there are so much diarehha even on haart?
why doesnt haart penetrate the gut mucosal tissue and stop virus rep. there? 

[lostboy]

I guess we're all screwed then! 

There seems to be so much they don't know about this disease, it is lucky that they have stumbled upon some medications, but according to this, the treatments are not even targeting the bulk of the infection.