HIV treatment – viral load
UK researchers found that it was necessary to suppress viral load to extremely low levels – no more than about 10 copies/ml – to make sure that HIV therapy worked in the long term.
At the moment, the goal of HIV treatment is often stated as being an undetectable viral load, often defined as below 50 copies/ml (until recently, this was the lowest detectable level for tests most commonly used in routine viral load monitoring). Having a viral load below this level is associated with a very low risk of HIV becoming resistant to the drugs used to treat it. Long-term suppression of the virus also allows CD4 cell count to recover and stay strong, reducing the risk of both HIV-related and non-HIV-related illnesses.
Some viral load tests are now sufficiently sensitive that they are capable of accurately measuring viral load to 40 copies/ml. In many cases they can also detect virus to levels as low as 3 to 10 copies/ml. Viral load at this extremely low level is called 'residual' and cannot be eradicated with current treatment.
Researchers wanted to see if a viral load above this residual level was associated with an increased risk of rebound – an increase in viral load to above 50 copies/ml or 400 copies/ml.
They therefore studied viral load in 1247 people. All were taking HIV treatment and had a viral load below 50 copies/ml.
A snapshot measurement of viral load was taken, and then the researchers looked at the risk of rebound over the next twelve months.
They found that 19% of participants had a viral load between 49 and 40 copies/ml; 40% had a viral load between 39 copies/ml and residual levels; and 40% had a viral load that was too low to measure, even with the sensitive test being used.
Compared to the people with truly undetectable viral loads, people with a viral load in the 49 to 40 copies/ml group were especially likely to experience an increase in their viral load to detectable levels. People with a viral load between 39 copies/ml and residual levels also had an increased risk.
The researchers suggest that their findings may mean that the goal of HIV treatment needs to be changed, with the definition of what is an undetectable viral load revised downwards.
But other doctors are less convinced. They point out that people with the lowest viral load had been taking treatment the longest. Therefore, they believe that the other people in the study may achieve full suppression of HIV with longer-term therapy.
But they think the findings could have implications for current US treatment guidelines. They set a viral load target of 200 copies/ml.
Lung cancer
Unlike some other studies, the researchers here found no evidence that either immune deficiency or a history of AIDS-related lung disease increases the risk of lung cancer.
Lung cancer is one of the more common non-AIDS-related cancers diagnosed in people with HIV.
This could be because smoking rates are high in HIV-positive people.
But the exact causes of the cancer are unclear.
Because of this, doctors in Switzerland looked at the medical records of 68 HIV-positive people who developed lung cancer between 1985 and 2010.
Each person was matched with five HIV-positive people who did not develop lung cancer.
Information on smoking, immune status, and history of HIV-related lung disease was analysed for both groups.
The researchers found that 85% of people diagnosed with lung cancer were current smokers, and 6% had been smokers. In contrast, 50% of the control group were current smokers, and a quarter were former smokers.
They found that being a current smoker was associated with a 14-fold increase in the risk of lung cancer.
Compared to people who had never smoked, the risk of lung cancer was also higher for former smokers. However, the risk was much lower than that seen in current smokers.
The researchers therefore comment: “The beneficial effects of quitting smoking appear, in relative terms, as important in HIV-infected persons as the general population.”
There was no evidence that CD4 cell count, a previous AIDS diagnosis, or a history of AIDS-related lung disease increased the risk of lung cancer.
“We observed a high prevalence of smoking…and the expected large increased risks for lung cancer among smokers,” write the authors.
HIV and pregnancy
In 1997 a fifth of all pregnancies in HIV-positive women involved people who had had at least one previous pregnancy. By 2009 this had increased to 37%.
Being able to become pregnant and to have a healthy baby is now a very real prospect for many HIV-positive women.
With the right treatment and care, the risk of mother-to-child transmission of HIV can be reduced to very low levels.
Modern HIV treatment means that the life expectancy of many HIV-positive people in the UK is now near normal.
But there’s very little information on how many HIV-positive women are having two or more pregnancies. This information is needed so that proper medical and social support can be provided.
Doctors from the UK and Ireland therefore looked at their records of pregnancies in HIV-positive women.
A little over 14,000 pregnancies were recorded between 1990 and 2009. Approximately a quarter were repeat pregnancies.
Accompanying improvements in HIV treatment and care, there was a big increase in both the number and proportion of repeat pregnancies.
There were 158 recorded pregnancies in 1997, and 32 (20%) were repeat pregnancies. By 2009, the total number of pregnancies had increased to 1465, with 565 (37%) being repeat pregnancies.
Further analysis of the 2009 figures showed that 28% were second pregnancies, 7% were third and 3% were fourth or subsequent pregnancies.
“The increase in repeat pregnancies over the last two decades is likely to reflect a combination of factors including the accumulation of diagnosed HIV-infected women who have already had a pregnancy,” suggest the investigators. “Major improvements in quality of life and AIDS-free survival of people living with HIV, and substantial reductions in the risk of mother-to-child-transmission are also likely to have had an impact.”