Prevention – pregnancy and increased transmission risk
Pregnancy doubles the risk of female-to-male HIV transmission, results of a large study show.
The Partners in Prevention study involved over 3400 couples where one partner was HIV-positive and the other HIV-negative. All the HIV-positive partners also had the genital herpes virus, HSV-2. The primary purpose of the study was to see if treatment with the anti-herpes drug, aciclovir, reduced the risk of HIV transmission, which it did not.
When the researchers looked more closely at the results of the study they found that rates of female-to-male HIV transmission were doubled if a woman was pregnant.
The researchers believe their findings have important implications, and point to a need “to strengthen family planning and maternal health services for women with and at risk for HIV in order to reduce unwanted pregnancies and avert HIV transmission to pregnant women and from pregnant women to their infants and partners”.
HIV treatment – changes to CD4 cell counts
Most patients experience a gradual increase in their CD4 cell count after starting HIV treatment. The suppression of viral load to undetectable levels allows the immune system to recover and CD4 cell count to rise, often to levels seen in HIV-negative people.
But this isn’t always the case. Despite having an undetectable viral load, some patients see only modest increases in their CD4 cell counts, and in some cases their CD4 cell count stays so low they remain vulnerable to serious infections and illnesses.
US researchers wanted to try and find possible causes. They noted that earlier research had shown that there were associations between a person’s genetic profile and changes in their CD4 cell count after starting HIV therapy.
Their study sample included approximately 425 people who were starting HIV treatment for the first time. All achieved an undetectable viral load, and changes in CD4 cell count were monitored one and two years after initiating therapy.
At the start of the study, the investigators examined the structure of the patients’ mitochondrial DNA. Mitochondria carry energy in cells, and the severe side-effects caused by some older anti-HIV drugs were connected to the damage they caused to mitochondria.
Overall, the patients had a good increase in their CD4 cell count – after one year of treatment it had increased by an average of 176, and the average two-year increase was 270 cells.
But they found that a number of genetic mutations in mitochondrial DNA were associated with lower CD4 cell increases.
The presence of a cluster of these mutations in black people was associated with lower overall CD4 cell increases.
However, the researchers note that their study was quite small and believe this question needs to be looked at in more detail through other studies.
Cardiovascular disease
But the study also showed that traditional factors for this early warning sign of cardiovascular disease were the biggest risks. These factors include high blood pressure and lipid levels (cholesterol).
It’s now well established that people with HIV have an increased risk of diseases such as heart attack and stroke. The causes are less clear. However, they seem to include the damage caused by untreated HIV, traditional risk factors for these conditions, and possibly the side-effects of some anti-HIV drugs.
Monitoring the hardening of the carotid artery in the neck and the coronary artery can help predict someone’s risk of cardiovascular disease.
Researchers found that people with HIV experienced faster thickening of these arteries than would be expected for individuals of their age.
But the research showed that the most important predictors of hardening of the arteries were risk factors such as blood pressure, insulin and glucose levels, and lipid levels. These are exactly the same factors associated with an increased risk of cardiovascular disease in the general population.
The researchers note: “Aggressive CV [cardiovascular] risk reduction with lipid-lowering and hypertensive medications appears to be effective at slowing the progression of atherosclerosis [hardening of the arteries] in HIV-infected patients.”
Good HIV care should include careful discussion of risk factors for heart disease before starting treatment, advice on risk reduction, and regular monitoring of lipid levels, blood pressure and blood glucose. Regular exercise and stopping smoking can reduce everyone's risk of heart disease.