Immediate ART in HIV patients prevented infection in partners

Issue: June 2011

HIV-infected men and women with otherwise healthy immune systems who initiated immediate oral antiretroviral therapy were 96.3% less likely to infect their uninfected partners and remained healthier compared with those assigned delayed treatment, according to new findings from a large-scale randomized controlled trial.

“With these results, we should redouble our efforts to diagnose individuals with HIV earlier,” Kathleen Squires, MD, chair of the HIV Medicine Association, said in a press release. “The US federal treatment guidelines were modified recently to recommend earlier treatment for people with HIV to improve health outcomes for this patient population. We now have further evidence that effective treatment not only benefits the individual but also will help reduce the spread of this disease.”

The phase 3 study, sponsored by the National Institute of Allergy and Infectious Diseases, was expected to run until 2015. However, the study was stopped early after finding that ART in this population provided significant protection to their partners.

Myron Cohen, MD, member of the Center for Global Health Policy’s scientific advisory committee, fellow of the Infectious Diseases Society of America and a member of the HIV Medicine Association, and colleagues assessed 1,763 couples in which one partner had HIV and the other partner did not.

Couples were recruited from 13 study sites across nine countries (Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand, US and Zimbabwe) and had a CD4 cell count between 350 cells/mm³ and 550 cells/mm³. Partners without HIV tested negative for the virus within 2 weeks of study entry. Median age was 33 years; 52% were male; and 97% were heterosexual.

Researchers grouped participants into an immediate treatment group, in which participants with HIV initiated a three-drug HIV treatment combination (n=886), or a deferred group, in which those who had HIV received ART after achieving a CD4 count less than 250 cells/mm³ or an AIDS-related event occurred (n=877), according to a press release.

Compared with 27 cases of HIV infection that occurred among the couples included in the delayed treatment arm, only one case of HIV infection occurred among those assigned immediate treatment. Moreover, 17 cases of previously undiagnosed extrapulmonary tuberculosis occurred among HIV-infected partners in the deferred treatment arm vs. only three cases in the immediate treatment arm.

“Confirmation of the protective effect of treatment on HIV transmission to sexual partners is a giant step forward in confronting the HIV epidemic,” Wafaa El-Sadr, MD, MPH, Center for Global Health Policy’s scientific advisory committee member, said in a press release. “The finding of a protective effect of HIV treatment on the development of extrapulmonary TB may play an important role in avoiding this deadly complication in HIV-infected individuals.”

The researchers said ART will be offered to all HIV-infected participants in the delayed treatment arm and all participants will be followed for at least 1 year.

The NIH’s announcement that ART reduces HIV transmission in discordant couples is an important, but expected finding. In 1994 monotherapy with AZT was shown to reduce mother-to-child transmission. Several subsequent trials established the potent efficacy of HAART in reducing HIV vertical transmission. In 2000 Dr. Thomas Quinn and colleagues established that heterosexual transmission of HIV is strongly associated with viral load. A recent meta-analysis in a Cochrane review examined seven observational studies, which together showed that ART reduced the rate for HIV transmission by more than 65%. These observational studies showed a protective effect, even when the HIV infected partner’s CD4 count was above 350 cells/mcL. Still, Dr. Myron Cohen and the other investigators of HPTN 052 have provided us with important data from a randomized, controlled clinical trial. We now know that ART very effectively reduces HIV sexual transmission, regardless of CD4 count. Hopefully, these data will be used to extend ART to individuals, who might not otherwise be eligible. According to WHO guidelines ART should not be given when a person’s CD4 count is greater than 350 cells/mcL. It is abundantly clear that HIV treatment blocks HIV transmission. For resource rich countries, such as the US, these data provide further support for the concept that by treating each HIV positive individual, this epidemic can be ended.

– Stephen Smith, MD

Infectious Disease News Editorial Board member

Disclosure: Dr. Smith reports no relevant financial disclosures

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