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Myron Cohen, University of North Carolina ©IAS/Marcus Rose/Worker's Photos

Results of a major trial showing that HIV treatment dramatically reduces the risk of transmission were greeted with a standing ovation at the Rome conference.

The HPTN 052 study showed that early treatment – started at a CD4 count between 350 and 550 – reduced the risk of HIV transmission to an uninfected partner, by at least 96%. Almost all the study participants were heterosexual couples.

Professor Myron Cohen said: “These are important results to give to a serodiscordant couple.”

The debate on the infectiousness of patients taking HIV therapy was kick-started by the release of the ‘Swiss statement’ in 2008, which said that – in certain circumstances – people taking successful antiretroviral therapy were not infectious to their sexual partners.

However, caution was urged. Professor Cohen reminded delegates that the average duration of follow-up in the HPTN 052 study was only 1.7 years.

A total of 28 infections could be genetically linked to an HIV-positive partner enrolled in the study – only one of these occurred in the immediate-treatment arm (participants in a deferred-treatment arm only started treatment once their CD4 count dropped to 250).

The transmission took place during the early weeks of treatment. The transmitting partner had a baseline viral load of 87,202 copies/ml, and after 28 days a viral load below 400 copies/ml.

Professor Cohen said that couples need to be counselled about the possible differences in risk between the first few months of treatment and later periods.

The researchers calculated that treatment reduced the risk of transmission by 96%.

In the deferred-treatment arm, the average viral load when transmissions occurred was approximately 80,000 copies/ml.

Michael C Thigpen, CDC and Jared Baeten, University of Washington ©IAS/Marcus Rose/Worker's Photos

Results from two pre-exposure prophylaxis (PrEP) studies show that taking anti-HIV drugs can protect women against infection with HIV.

Preliminary results from the studies – called the Partners PrEP trial and the TDF2 study – were announced last week. Their results showed that PrEP reduced the risk of transmission by between 62 and 78%.

Therapy consisted of either tenofovir or tenofovir/FTC (Truvada), and its protective effects were compared against a placebo.

The new data were keenly anticipated because another study of PrEP in women, FEM-PrEP, closed recently after finding zero efficacy for Truvada, and it had been theorised that oral PrEP might not work for women because drug concentrations in the genital tract were too low.

However, results of these two studies showed that PrEP was equally effective at preventing infections in men and women.

Levels of adherence to treatment were high and enrolment in the study didn’t appear to increase rates of unprotected sex.

Beatriz Grinsztejn, Oswaldo Cruz Foundation, Brazil and Mina Hosseinipour, UNC Project, Malawi ©IAS/Marcus Rose/Worker's Photos

Early HIV treatment reduced rates of serious illnesses by 40%, results from the HPTN 052 study show.

However, this reduction was almost entirely due to fewer cases of extrapulmonary tuberculosis (TB infection outside the lungs, such as in lymph nodes or joints).

Starting HIV treatment early did not reduce the overall risk of death, or rates of serious bacterial infections and pulmonary TB (TB infection of the lungs).

The HPTN 052 study showed that early HIV treatment reduced the risk of HIV transmission to serodiscordant partners by 96% (see first story).

Researchers also wanted to see what impact earlier therapy had on HIV-related outcomes. The study recruited participants in Africa, Asia and the Americas.

All 1763 patients had CD4 cell counts between 350 and 550 cells/mm³.

Patients were randomised to either start HIV therapy immediately, or to wait until their CD4 cell count fell to below 250 cells/mm³ (the level at which treatment was recommended to begin, in relevant national guidelines, during the study recruitment period).

Overall, 105 patients developed a serious illness, and the risk was significantly higher for patients in the deferred-treatment arm.

However, this was due to higher rates of extrapulmonary TB among patients who deferred therapy.

Rates of pulmonary TB were the same in the immediate- and deferred-treatment arms. There were 16 cases of serious bacterial infections in patients who took immediate treatment, compared to 14 cases in patients who waited to start treatment.

Mortality rates were also comparable – 13 patients who started immediate therapy died, compared to ten patients who initiated therapy when their CD4 cell count fell.

In both study arms 14% of patients experienced a serious adverse event.

A large US study has shown that the relationship between HIV treatment and bone disease is far from straightforward.

A number of studies have shown that people with HIV have an increased risk of bone problems, such as osteoporosis. The exact causes and consequences are uncertain.

Researchers from the US Department of Veterans Affairs looked at rates of fragility fractures – of the hip, wrist and lower vertebrae – in over 56,000 HIV-positive people between 1988 and 2009.

They found that there was a big leap in the incidence of fractures after 1996, when effective HIV treatment became available.

Traditional risk factors for fragility fractures – such as older age, smoking, diabetes and co-infection with hepatitis C – were all important risk factors for this group of people.

Indeed, the researchers think that the increased incidence of fractures after 1996 could simply be because people with HIV are living longer.

However, when they restricted their analysis to people who received care in the treatment era, they found that treatment with tenofovir (Viread, also in the combination pills Truvada and Atripla) was a risk factor for fractures, as was therapy with the protease inhibitor lopinavir/ritonavir (Kaletra).

Their results showed that each year of treatment with tenofovir increased the risk of a fracture by approximately 12%.

Using tenofovir and Kaletra in the same combination increased the risk of fractures further. However, the researchers pointed out that the risk associated with these drugs was minimal when compared to those associated with traditional factors.

Indeed, they were far from convinced that HIV therapy was a major cause of fractures, commenting: “Cumulative antiretroviral exposure likely does not account for the increased risk in the HAART era.”

Hardening of the arteries is accompanied by bone loss in people with HIV.

Italian investigators found that calcification of the coronary artery – an early warning sign of cardiovascular disease – was associated with bone loss in the hip.

Their study involved 812 people who received care between 2006 and 2010.

They found that hardening of the coronary artery was associated with a number of traditional risk factors, for example smoking, diabetes, high blood pressure and older age.

Bone loss in the hip was seen in 22% of people with evidence of calcification in the coronary artery, and in 15% of those people without hardening of this artery.

A series of statistical analyses found that a number of risk factors were associated with coronary calcification and bone loss in the hip – these included traditional risk factors and some HIV-related factors such as CD4 cell count, viral load and treatment with some anti-HIV drugs (for example, tenofovir).

The researchers emphasised that lifestyle changes such as regular exercise, a good diet, and stopping smoking could reduce both cardiovascular and bone problems in patients with HIV.

Images from presentation by Craig Cohen of University of California, San Francisco

An HIV-positive woman has a higher risk of transmitting HIV to her sexual partner if she has bacterial vaginosis, a study presented to the conference shows.

Bacterial vaginosis (BV) is a condition which occurs when the normal balance of bacteria in the vagina becomes disrupted. This can result in an over-growth of certain bacteria, which may be accompanied by symptoms such as discharge, itching and pain. It can sometimes cause pelvic inflammatory disease and lead to problems with fertility and childbirth.

Earlier research had shown that having BV increases the risk of a woman becoming infected with HIV.

Now investigators have found that a man who is in a relationship with an HIV-positive woman has a three times higher risk of acquiring HIV if his partner also has BV.

Genital tract viral load was higher in women with BV but researchers do not think this explains the increased risk of transmission.

Rather, they suggest that normal levels of vaginal bacteria could kill HIV, reducing the proportion of virus that is infectious.

The researchers also believe that BV could indirectly increase the male partner’s susceptibility to HIV. They noted that long-term sexual partners share genital flora, with men acquiring bacteria from their partners. They suggested that bacteria may activate Langerhans cells and CD4 cells, making the man more susceptible to HIV infection.