- LONDON (Reuters) - A scanning
technique can track the progression of HIV and could lead to new treatment
options and the development of the next generation of anti-AIDS drugs,
scientists said on Friday.
- Positron emission tomography (PET) scans are usually
used to identify cancerous tumors, but researchers in the United States
believe the technology could play an important role in the battle against
AIDS by identifying the impact of the virus on lymph nodes which could
be treated with radiotherapy or surgery.
- Dr C. David Pauza and scientists at the University of
Maryland Biotechnology Institute in Baltimore Maryland took whole body
PET scans of 15 HIV patients and found fairly distinct sites of immune
response during different stages of the illness.
- "We believe that if we identify those sites clearly
during HIV infection we encourage people to consider these types of interventions,"
Pauza said in an interview, referring to surgery or radiotherapy.
- During early disease, lymph nodes in the head and neck
were activated, according to the PET scans, but in later stages the virus
stimulated an immune response in areas of the torso and later in the bowel.
- HIV/AIDS is treated with antiretroviral drugs. Surgery
or radiotherapy would open up a new approach to the illness that has affected
42 million people worldwide.
- "We are not aware that it has ever been tried,"
said Pauza, who reported his findings in The Lancet medical journal.
- "We think it is appropriate to consider these approaches
and also appropriate to learn from the cancer models because cancer is
a disease of chronic cell activation and growth and in some ways, even
though HIV is triggered by a virus, it has some similarities," he
- In cancer patients, PET scans measure the activity of
cancerous cells, while in HIV it picks up levels of immune system reaction.
- David Schwartz and Sujatha Iyengar, of the Johns Hopkins
University Bloomberg School of Hygiene and Public Health who also used
PET scans to track HIV progression, said lymph node removal could give
patients an opportunity for a break in antiretroviral treatment.
- "Although many systemic sites from which latent
virus could be re-activated would be left, re-activation might not occur
for months or years after removal of the active nodes, thereby allowing
extended interruption of treatment," Schwartz said in a separate study
published in The Lancet.
- Pauza also suggested that with the pattern of progression
detected with the PET scans it could be possible to develop a prognostic
tool for HIV, new drugs for patients in whom existing therapies have failed,
or other illnesses.
- "One thing we discovered as we were going through
this work is that there was a substantial amount of undiagnosed cancer
associated with HIV. We observed a number of patients with lymphoma,"
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