AIDS virus may hide in the gut: study

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AIDS virus may hide in the gut: study

WASHINGTON (Reuters)

AIDS virus hides out inside people's intestines, researchers said on

Saturday in a report that offers new understanding of the incurable

infection

The virus replicates in the lining of the gut and does much of its

damage to the immune system there, Satya Dandekar, chairwoman of the

Department of Medical Microbiology and Immunology at the University

of California Health System, and colleagues reported.

Writing in the Journal of Virology, Dandekar said the study was the

first to explain why the drug cocktails taken by HIV patients so

often fail to work completely.

" The real battle between the virus and exposed individuals is

happening in the gut immediately after viral infection, " she said in

a statement.

" We need to be focusing our efforts on improving treatment of gut

mucosa, where massive destruction of immune cells is occurring. Gut-

associated lymphoid tissue accounts for 70 percent of the body's

immune system. Restoring its function is crucial to ridding the body

of the virus. "

HIV cannot be cured but the drugs, known as highly active

antiretroviral therapy, or HAART, can keep the virus under control.

At first, doctors had hoped that years of treatment might eventually

eradicate the virus, but, 25 years into the epidemic of AIDS, it is

clear that cannot happen. That is because the virus can hide out

quietly in reservoirs, which include certain immune cells.

The gut is clearly important, too, Dandekar's team said.

" We found a substantial delay in the time that it takes to restore

the gut mucosal immune system in those with chronic infections, "

Dandekar said. " In these patients the gut is acting as a viral

reservoir that keeps us from ridding patients of the virus. "

The mucosa are the wet tissues that line the nose and throat, the

genitals and the inside of the gut. HIV often infects people via the

mucosa.

Dandekar's team has been studying HIV-infected patients who, even

without treatment, have survived more than 10 years with healthy

immune systems, including the T-cells that are attacked by the virus.

" We looked at their gut lymphoid tissue and did not see loss of T-

cells there. This correlated with better clinical outcomes, "

Dandekar said.

So they started the current study, following 10 patients being

treated with HAART, taking blood and gut samples before and after

three years of treatment.

They found evidence of inflammation, which disrupts tissue function,

promotes cell death and upsets the normal balance of gut bacteria.

Dandekar said these findings suggest anti-inflammatory drugs may

help HAART work better.

http://news./s/nm/20060729/sc_nm/aids_gut_dc