This release is available in French.
Montreal, April 14 2009 Begin treatment as early as possible: this general common sense rule seems to apply to most diseases except HIV-AIDS, which is only treated once a certain number of immune cells called "CD4+" cells have disappeared. The results of a North American study, which involved the team of Dr. Marina Klein of the Research Institute of the MUHC, run contrary to this consensus. The findings show that the risk of death in seropositive patients decreases by 69% to 94% if they start treatment earlier than officially recommended.
This study, which was recently published in the New England Journal of Medicine, could have considerable influence on medical practice.
Early treatment decreases the risk of death
In more precise terms, the risk of death decreases by 94% for patients who begin anti-HIV treatment when their CD4+ cell counts are above 500 cells per millilitre compared with those who start with a count below 500. Patients who begin treatment with a CD4+ cell count between 350 and 500 cells per millilitre see their risk of death reduced by 69% compared with those who begin at a lower count of 350.
"The official guidelines recommend starting anti-HIV treatment when the patient's CD4+ cell count is less than 350 cells per millilitre. This recommendation was formulated from data based on older medications that produced more side effects than current treatments," explained Dr. Klein. "Current therapies cause fewer side effects, are better tolerated and more effective so we can safely start treating patients earlier."
This study is the first of its scope to measure the risk of death based on the progress of infection at the start of treatment. The information was drawn from a number of databases in North America, including one managed by Dr. Klein at the Montreal Chest Institute,. In total, the researchers analyzed data from 17517 patients between 1996 and 2005.
and disease in general
"We have noticed that HIV treatments may decrease the impact of non-AIDS-related diseases, such as cardiovascular disease, liver disease, or cancer. This may be a reason why early treatment can decrease the risk of death overall," Dr. Klein continued. "We do not know the precise mechanisms behind this observation, but there are two plausible hypotheses. First, the medications seem to be more effective at supporting the immune system by acting earlier; second, they appear to prevent the HIV virus from replicating, which reduces inflammation."
Despite current treatment guidelines, there has been a growing trend to treat patients earlier and earlier once the virus is detected. This study could therefore reinforce this trend and possibly bring about an official change in the guidelines.
|Contact: Isabelle Kling|
McGill University Health Centre