- Patients usually only receive antiretrovirals once their immune system has been weakened by the infection
- Trial found giving course of treatment after diagnosis had long-term protective effect
- Virus levels remained low long after early treatment finished - so lowering risk of passing it on
A mature HIV infection (blue cells) spreads: Scientists say treating the virus early could reduce the risk of passing it on
Giving HIV drugs to a patient as soon as they are diagnosed could slow the damage to their immune system and delay the need for long-term treatment, say researchers. This in turn, could reduce the spread of the disease.
Patients don't usually receive antiretroviral therapy until their immune system has been significantly weakened by the infection.
However, a team from Imperial College London found giving treatment as soon as possible had a long-term protective effect lowering the amount of virus in the blood for up to 60 weeks after it was stopped.
Study leader Dr Sarah Fidler said: 'These results are promising and suggest that a year-long course of treatment for people recently infected with HIV may have some benefit on the immune system, as well as helping control the virus.
'The treatment also reduces the amount of virus in the body for some time after the patient has stopped taking the medication. This could be very important for helping reduce the risk of passing on the virus to a sexual partner.'
Scientists studied 366 HIV patients who had all been diagnosed within six months of being infected.
Some patients were given 12 weeks of drugs after being diagnosed while another group had drugs for 48 weeks after diagnosis. A third group were given no drugs until their immune system was compromised - when disease fighting cells (CD4 T-cells) reached 350 cells per cubic millimetre of blood.
In a healthy adult the T-Cell count is between 600 and 1200.
The researchers then measured the time until each volunteer's T-cell count dropped below 350 or they began a lifelong course of antiretroviral medication.
On average, participants who had received no medication needed to begin taking a lifelong course of treatment 157 weeks after infection.
Those in the group receiving antiretrovirals for 12 weeks began their lifelong course of treatment on average 184 weeks after infection (a delay of 27 weeks not considered as a significant effect by researchers).
However, those volunteers who received antiretrovirals for 48 weeks took an average of 222 weeks before beginning long-term treatment - a delay of 65 weeks.
Plus over the whole time of the study, participants on the 48-week course had higher CD4 T-cell counts than those in the other two treatment groups.
This potentially reduced their risk of developing secondary infections such as tuberculosis. They also had lower levels of HIV in the blood for more than a year after stopping treatment compared to the other volunteers, which could play a part in reducing the risk of passing on the virus to sexual partners.
The researchers found no evidence that treatment within the first six months of infection led to the virus becoming resistant to the drugs or that coming off the course led to unexpected deaths or damage to the immune system.
Professor Jonathan Weber, chief study investigator, said it reinforced the importance of regular testing: 'Early testing and diagnosis are incredibly important. When a person first contracts HIV, they are at their most infectious, but they are also often unaware that they have contracted the disease and hence are more likely to spread the infection.
'The sooner they can be diagnosed, the better our chances of limiting the spread of the virus and the sooner they can be offered appropriate guidance and counselling.'
However, the cost could be an obstacle to rolling out such treatment in poorer parts of the world.
In the UK, around a quarter of people with HIV are thought to be unaware they have the infection.
The study, published in the New England Journal of Medicine, is the largest clinical trial to have looked at treating people with recent HIV infection.
By CLAIRE BATES
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