Biomarker May Signal HIV Progression

FRIDAY, March 28 (HealthDay News) -- Researchers at Temple
University think they may have found a blood marker that denotes the
progression of the virus that causes AIDS.

The researchers found an increase in the CD163+/CD16+ monocyte subset
may coincide with the advancement of human immunodeficiency virus (HIV),
according to a study published in the March issue of AIDS Research and
Human Retroviruses.

"It looks like, based on these correlations, that this particular cell
type may be involved in immune impairment and the progression of HIV," Jay
Rappaport, a professor of neuroscience and neurovirology who oversaw the
study, said in a prepared statement. "Is it a good prognostic indicator?
If you have a lot of these monocytes, does it mean you are going to
progress into AIDS faster? Right now, all we know is what the correlations
are."

A monocyte is a specific white blood cell, a part of the human body%26#39;s
immune system that protects against blood-borne pathogens and moves
quickly to sites of infection within the body%26#39;s tissues. As monocytes
enter tissue, they undergo a series of changes.

The researchers investigated these alterations by examining 18 patients
with HIV and seven individuals without HIV.

"We did, indeed, find that patients with detectable virus had an
increase of this monocyte subset that correlated with the amount of virus
they had in their blood," study author Tracy Fischer-Smith, an associate
scientist in Temple%26#39;s Neuroscience Department, said in a prepared
statement. "We were surprised to find that in patients with CD4+ T-cell
counts of less than 450 cells per microliter [200 or less per microliter
is defined as AIDS], the increase of this monocyte subset correlates
inversely with the number of T-cells."

Fischer-Smith said this finding suggests that as the monocyte cells are
increasing, these patients are losing CD4+ T-cells, which are critical for
maintaining one%26#39;s immune system.

"This may actually provide an earlier window into what is happening
with HIV-infected patients where we might be able to see that immune
impairment is taking place before we see a dramatic loss of CD4+ T-cells,"
she said.

The researchers plan to expand this study by following a cohort of
patients over time to see if their findings can provide doctors with an
early warning system and help them design better therapeutic strategies,
Fischer-Smith said.

More information

The U.S. Department of Health and Human Services has more about HIV and AIDS.