Staying well with HIV

by Edwin J Bernard

In the UK and other rich countries, we’re now expected to live more or less a normal lifespan – as long as we are diagnosed with HIV early enough to benefit from anti-HIV drugs, and can take them regularly and on-time for the rest of our lives. And when we do eventually die, it’s not likely to be of AIDS – we’re more likely to succumb to liver or heart disease or to cancers that have not been associated with HIV in the past. Several new studies presented at the Fourteenth Conference on Retroviruses and Opportunistic Infections (CROI) held in Los Angeles in February provide us with some explanations as to why this is so – and what we can do about it.

Smokers triple their cancer risk

Last year, an ATU cover story (ATU 159, Sept/Oct 2006) explained that HIV-positive smokers were much more likely to die sooner than HIV-positive non-smokers. Now two more studies suggest that there are compelling reasons why people with HIV should stop smoking.

The D:A:D (Data Collection on Adverse Events of Anti-HIV Drugs) study team reported that deaths from non AIDS-defining cancers were now more common than deaths from AIDS-defining cancers. The four most frequently reported fatal non-AIDS cancers were lung cancer (20% of cases); cancer of the gastrointestinal tract, such as stomach or liver cancer (13%); cancers of the blood and lymphatic system, such as Hodgkin’s lymphoma (7%); and anal cancer (7%).

When they investigated the factors that put people at risk for these cancers they found that current tobacco smokers were three-times more likely to die of cancer, notably of the lungs.

A second study, undertaken amongst gay men in Germany, found that smoking increases the rate of human papilloma virus (HPV) reproduction. The association between smoking and viral load was particularly strong in men who had been infected with anal cancer-associated HPV (types 16 and 18) but had not yet developed precancerous changes, suggesting that smoking may possibly speed the development of anal cancer.

In addition, the D:A:D study found that people with active hepatitis B virus infection doubled their risk of liver cancer-related death.

CD4 counts matter

We’ve known for a long time that an HIV-positive person was more likely to develop an AIDS-defining illness when they had low CD4 counts. That’s why anti-HIV therapy is effective in preventing AIDS: it raises CD4 counts.

The D:A:D study is the largest study so far to show that this is also the case for the cancers that haven’t traditionally been linked to AIDS. It found that the relative risk of dying from either AIDS-defining or non-AIDS-defining cancers increased gradually as CD4 cell counts fell.

These results agree with data from another study presented at CROI. The FIRST study found that lower CD4 cell counts in people on anti-HIV therapy were associated with an increased risk of developing non-AIDS-defining cancers.

Is it ageing?

In the D:A:D study, the overall risk of both types of cancer was higher amongst older individuals, but the risk of non-AIDS-defining cancer increased more steeply than that of AIDS-defining malignancies with every additional five years of age.

However, Jason Baker, lead author of the FIRST study, told the conference that becoming ill even when HIV is well controlled by anti-HIV drug isn’t just about ageing. “The fact that it’s associated with CD4 level starts to build the case that these people aren’t just getting these illnesses because they’re living longer.”

Dr Baker suggests that starting treatment at higher CD4 counts – which would reduce the risk of ever having low CD4 cell counts – might be the solution for people who haven’t yet begun anti-HIV treatment.

 

Three basic things

However, for those of us already on anti-HIV treatment, these studies (and the SMART heart disease study reported on page 14) suggest there are also some things we can do to reduce the risk of becoming seriously ill.

• Stop smoking.
• Get treat for, or vaccinated against, hepatitis B.
• Don’t interrupt anti-HIV treatment.

References

All from 14th CROI, Los Angeles, 2007.

Marconi VC et al. HIV-induced immunodeficiency and risk of fatal AIDS-defining and non-AIDS-defining malignancies: results from the D:A:D Study. 84

Baker J et al. HIV-related immune suppression after ART predicts risk of non-opportunistic diseases: results from the FIRST study. 37

Brockmeyer N et al. Elevated anal HPV16 DNA loads in HIV+ men who smoke. 872