HIV study warns against complacency

November 27, 2013 7:20 PM

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No such thing as safe levels of infection

MONTREAL — Now that HIV is no longer an automatic death sentence, there’s a misperception among some patients that a low viral load is as good as being cured.

Not so, warns a Montreal study on human immunodeficiency virus (HIV), which concludes that there is no such thing as safe levels of infection when it comes to the virus.

A Université de Montréal study led by doctoral student Claudie Laprise found that even minuscule amounts of virus in the blood doubles the risk of illness.

That’s a concern not only for patients’ health, but also from a public health perspective, said Mark Wainberg, director of the McGill University AIDS Centre, who was not involved in the research.

The research shows that when the virus is not suppressed to a level where it is undetectable, “there’s a risk that you could be in trouble down the road,” Wainberg said. “Residual virus can do a lot of damage. All levels of persistent low level (viral load) were associated with ultimate treatment failure. We’re talking about the virus coming back and that’s associated with illness progression and death.”

Advances in medication such as antiretroviral drugs dramatically increased the prognosis of people with HIV, an infection which gradually destroys the immune system.

In about 10 per cent of HIV patients, the drugs may not be effective in suppressing the virus, which is required to prevent the disease from progressing to acquired immunodeficiency syndrome (AIDS).

The so-called detection limit for the virus, the amount of virus necessary to show up on a test, is 50 copies of the virus per millilitre of blood.

“Anything above the detection limit is a danger zone,” said lead author Laprise, currently a post-doctoral student at McGill University, whose study was published recently in the journal of Clinical Infectious Diseases.

Even patients with extremely low levels of the virus, Laprise said, are at risk of developing resistance to drugs, or seeing their disease mutate.

Yet there are no therapeutic guidelines for doctors treating people whose infection levels is just over the limit of what is considered undetectable.

The study was done in close collaboration with a team of doctors at Montreal’s Clinique Médicale du Quartier Latin, based on data of 1,860 people living with HIV since 1997.

Laprise’s study compared the progression of HIV in people with a persistent viral load above the detection limit.

All levels of virus in the blood led towards a “virological failure,” a term that means the antiretroviral drugs were failing as a treatment to keep the virus at bay.

Just having a persistent level of virus, even if it is extremely low, is a risk factor in itself. The higher the viral load, the higher the risk, Laprise said.

A patient with a viral load of 500 to 999 copies per millilitre is at five-times higher risk of virological failure compared to patients whose viral load is undetectable. Nearly 60 per cent of that group suffered disease progression.


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