HIV update - 4th September 2019

How adherent do you need to be?

In recent years, anti-HIV medications have become more effective. Doctors often say that many of them are more ‘forgiving’, meaning that occasional lapses in adherence won’t necessarily result in the treatment no longer working.

A group of researchers wanted to see what levels of adherence are needed to achieve and maintain undetectable viral loads in the modern treatment era. Their small study provides some interesting clues although larger studies would be needed to provide a more definitive answer.

Looking at data for 570 adults living with HIV across the United States, they examined data on adherence (specifically, the proportion of days for which a person had medication available during a given period of time) and undetectable viral loads (below 200 copies).

People who had medication for fewer than 80% of days did worse. But when researchers compared people with enough medication to cover 80 to 90% of days, and people with enough for 90 to 100% of days, they found no differences in the number with an undetectable viral load.

They also calculated the adherence rate required to achieve an undetectable viral load in 90% of viral load tests. They found that this was 82% – far below the ‘gold standard’ of 90 or 95% that is sometimes recommended. But this varied according to class of HIV drugs:

• For integrase inhibitor-based regimens, it was 75%.
• For non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens, it was 78%.
• For protease inhibitor (PI)-based regimens, it was 87%.

This tells that integrase inhibitors (dolutegravir, elvitegravir and raltegravir) are the most forgiving of anti-HIV drugs today. The study also provides reassurance that occasional missed doses are unlikely to have serious consequences.

But before aiming for an adherence level of 75%, it’s worth asking yourself whether you’d be happy with being undetectable for just 90% of the time. It would be interesting to see what adherence level is required to be undetectable for 95% or 99% of the time, but the researchers don’t report their data on that.

For more information, read NAM's page 'Adherence to HIV treatment'.

Chlamydia and anal cancer

Most cases of anal cancer are linked to human papillomavirus (HPV), a very common infection that can be passed on during sex. HPV is not a single virus – there are about 150 types of HPV that have different effects. Some types of HPV don’t seem to do any harm, other types cause anal and genital warts, while others can cause anal and cervical cancer. HPV16 and HPV18 are the types most likely to cause cancer.

Most adults have had HPV infection. Very often, the body can get rid of the virus without you ever knowing you had it. In people living with HIV, the body seems to be less able to get rid of HPV on its own.

But scientists don’t have a clear idea of why a few people with high risk types of HPV go on to have cancer, while most people do not. Now a study suggests that people who have both HPV and chlamydia are more like to go on to have anal cancer. It’s already known that HPV and chlamydia together contribute to cervical cancer, but this hasn’t been shown for anal cancer before.

In a cohort of 145 HIV-positive gay and bisexual men, co-infection with HPV16 and chlamydia was the most important risk factor for pre-cancerous abnormal lesions. Other STIs didn’t appear to be linked to pre-cancerous lesions in the same way.

The researchers say that regular screening for anal infection with chlamydia is important for gay and bisexual men living with HIV.

For more information, read NAM's page 'Anal cancer and HIV'.

Lowering cholesterol and triglycerides

You may have been told by your doctor that your levels of LDL cholesterol and triglycerides are too high and that you need to bring them down. Some of the ways to do this include eating less fatty food, being physically active, lowering your weight, stopping smoking, drinking less alcohol and taking statin medications.

A small Brazilian study compared outcomes in people living with HIV who had abnormal cholesterol or triglycerides. Each person was randomly allocated to one of four groups:

• statins
• exercise (a combination of resistance training and treadmill sessions three times a week)
• statins + exercise
• nothing.

The people in the statins-only and exercise-only groups did better than those who didn’t do anything. However, the best results were seen in individuals who combined statins and exercise.

Cholesterol and triglycerides were reduced, as were markers of inflammation associated with an increased risk of cardiovascular disease, while body composition, cardiovascular fitness and muscle strength also improved.

For more information, read NAM's page 'Exercise'.

Hepatitis C and inflammation

Research has shown that chronic inflammation – the immune system’s long-term activation in response to HIV, hepatitis C and other health challenges – may contribute to the earlier onset of heart disease, cancers and other illnesses in people living with HIV.

Now a small study, conducted with women living with both HIV and hepatitis C, suggests that curing hepatitis C may reduce inflammation in people with co-infection. After successful hepatitis C treatment, there were small but statistically significant decreases in some chemicals associated with inflammation which are thought to contribute to the development of heart disease.

This suggests that treating and curing hepatitis C may reduce people’s long-term risk of developing other health problems.

For more information, read NAM's page 'Hepatitis C treatment for people with HIV'.