Early HIV treatment delays immune system damage and cuts transmission risk

Taken from the New England Journal of Medicine (NEJM) – by Bruce Sylvester – Forty-eight weeks of antiretroviral treatment in the early stages of HIV infection delays damage to the immune system and delays the need for long-term treatment, researchers reported on Jan. 16, 2013 in the NEJM.

Findings from the study also suggest that early treatment  lowers viral load in the blood for up to sixty weeks after it is stopped, potentially cutting the risk of onward transmission.

SPARTAC (Short Pulse Anti-Retroviral Therapy at HIV Seroconversion), was a randomized, controlled, international  trial, conducted over five years and enrolling 366 adults, mostly heterosexual women and gay men.  It was coordinated by researchers from Imperial College London, UK and the Medical Research Council’s Clinical Trials Unit, with immunology research conducted by the University of Oxford, UK.

As background, the authors noted that prior observational studies had suggested that treatment at the time of HIV infection could delay the amount and speed of immune damage, thereby also, possibly,  delay the need to start lifelong antiretroviral therapy. SPARTAC is the first large randomized study to test this hypothesis.

SPARTAC subjects were identified within six months of infection. They were randomized to antiretrovirals for either 48 weeks or 12 weeks — or to receive no medication (standard practice in HIV management at this stage of infection).

The investigators charted timing until each subject’s  CD4 T-cell count fell below 350 cells per cubic millimetre and/or they began a lifelong course of antiretroviral medication.

They reported that, on average, subjects who received no antiretroviral therapy needed to begin such treatment 157 weeks after infection.

Those in the group receiving antiretrovirals for 12 weeks began lifelong treatment on average 184 weeks after infection, not deemed a significant effect).

Subjects who received antiretrovirals for 48 weeks took an average of 222 weeks before beginning long term treatment – a delay of 65 weeks. This was an important delay, but, overall, was not significant considering the time that the 48-week subjects had already spent on treatment. Notably, subjects on the 48 week course had higher CD4 T-cell counts than the other subjects. Also, they had lower levels of HIV in the blood for over a year after stopping treatment compared to the subjects, possibly reducing the risk of disease transmission.

Professor Jonathan Weber, Imperial College, London, the chief study investigator, said that the study highlights the importance of frequent testing for HIV, especially in high risk groups. He said, “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….If, as our study suggests, they can then be treated in such a way as to slow the progression of the disease and reduce their risk of secondary infections from potentially deadly diseases such as TB, then this offers a win-win situation.”