HIV, treatment and cholesterol
There has been a lot of research into the links between HIV, HIV treatment and heart disease.
Now, researchers have found that people who experienced cardiovascular disease while taking a break from HIV treatment had lower levels of HDL, or ‘good’ cholesterol, but not of LDL, or ‘bad’ cholesterol.
The SMART study had previously found there was an increase in heart problems (cardiovascular disease, or CVD) amongst people who took breaks from HIV treatment.
SMART researchers have now looked at the effect of stopping treatment on the levels of LDL and HDL cholesterol and the size of LDL and HDL particles. They found that levels of HDL cholesterol went down more in those people who stopped treatment compared to those who kept taking treatment, and that their HDL particles were smaller – and that these factors were linked to an increased risk of CVD.
High cholesterol can be treated by drugs that aim to lower lipids, or types of fat, in the blood. A separate study in California has found that lipid-lowering drugs work in people with HIV, although not quite as well as in HIV-negative people.
Both HIV and HIV treatment can have an effect on levels of blood fats, such as cholesterol and triglycerides. Other risk factors for CVD include smoking or being an older age. To manage CVD risk, doctors usually recommend that people make changes to their lifestyle – such as having a healthy diet, not smoking and taking regular exercise. If this doesn’t bring down blood fats, drug treatments can help.
People on HIV treatment have to be careful which lipid-lowering drug they take because of possible interactions between it and the antiretroviral treatment. Pravastatin is most often used and the Californian study found it was slightly less effective in HIV-positive people.
Study results also showed that some HIV-positive people taking a drug called gemfibrozil to reduce their triglyceride levels did less well than those who were HIV-negative – but the drug worked as effectively in people taking non-nucleoside reverse transcriptase inhibitors (NNRTIs) as it did in HIV-negative people.
But the doctors in the study emphasised the importance of a healthy lifestyle, to avoid developing any additional risk factors such as obesity or high blood pressure.
Treatment news
HIV treatment is now so effective that, if someone takes it properly (adherence), it can stop the virus from reproducing itself completely.
But researchers trying to find ways of getting rid of the virus altogether in the body (‘viral eradication’) have not so far been successful. A recent study has shown that small amounts of HIV continue to be released from places in the body even when people are on successful treatment.
Doctors had hoped that any residual replication of the virus could be stopped by adding another drug to the treatment combination. They discovered that the HIV remaining in these ‘reservoir’ sites in the body is stable and isn’t affected by drugs that prevent replication.
The challenge now will be to find a strategy that eradicates HIV from the body. In the meantime, the aim of HIV treatment is an undetectable viral load, and successful treatment means that people with HIV can lead long, healthy lives.
Gay men and transmission risks
Research conducted in Brighton has found that being recently infected with HIV, having a higher viral load and having other sexually transmitted infections (STIs) all increase the chances of a gay man passing on HIV.
Researchers had already made these links in cases of heterosexual transmission but weren’t sure if they also applied in new infections amongst gay men. This research showed there was clear evidence of a link between both recent infection and a higher viral load and transmission of HIV. A recent STI also increased the risk.
Taking HIV treatment was associated with a 96% reduction in the risk of transmission.
Treatment as prevention
The potential for treatment to be an effective means of preventing further HIV infections has been supported by several of the pioneers of HIV and AIDS research.
They suggest that universal testing and treatment offer the best hope of controlling the HIV pandemic.
A court in Switzerland has accepted that the risk of sexual transmission of HIV when the infected partner is successfully on treatment is 1 in 100,000. This was evidence given to the court by Professor Bernard Hirschel, one of the authors of the Swiss statement in January 2008. The defendant, who had already been found guilty of having unprotected sex without disclosing his HIV status, was acquitted as the charges were dropped on the basis of this evidence.
It has been suggested that the ruling may mean that in Switzerland HIV-positive people, on successful treatment, should no longer be prosecuted for having unprotected sex. This may have an impact in other countries where there are laws on criminal HIV exposure.HIV and hepatitis
A study has found that a high level of hepatitis C virus in the blood may increase the chance that someone with both HIV and hepatitis C will die as a result.
Earlier research had suggested there was no increased likelihood that co-infected people would have an increased risk of death.
Now this study has looked at the hepatitis C viral load in people with both conditions and found that having an undetectable or low viral load meant people had very similar rates of death as those without hepatitis C. Those with a high hepatitis C viral load were more likely to die during the course of the study, with a slightly increased chance of dying of liver-related causes. It was suggested that the effect of a high viral load may be more obvious in people with HIV.
There is some evidence that HIV treatment can slow the progression of liver damage in people co-infected with hepatitis C. Now a study has shown that antiretroviral treatment can result in significantly improved chances of survival for those who have developed liver cirrhosis. The research showed that continuous HIV treatment was more effective at delaying the start of more serious liver problems than hepatitis C treatment. People who had a break in their HIV treatment also reduced the time until they developed these problems.
Hepatitis C treatment often doesn’t work when co-infected people have cirrhosis of the liver, so doctors try to prevent hepatitis progressing this far, through screening for the disease, regular liver function tests and treating people soon after diagnosis with hepatitis C. This has the best chance of success and it is possible for people with both HIV and hepatitis C infection to be cured of hepatitis.
HIV doesn’t increase risk of melanoma
American researchers have found that a weak immune system doesn’t increase the risk of the skin cancer melanoma.
But their research did show that people with HIV had an increased risk of developing some rarer skin cancers, and that risk could be related to the immune damage HIV causes.
The researchers looked at rates of melanoma and two rarer cancers called Merkel cell carcinoma and appendageal carcinomas in people with HIV who had a weak immune system and had been diagnosed with AIDS. They then compared these rates to those seen in the general population.
There was no real increase in the risk of melanoma, and there was no evidence that the risk of this cancer increased as people’s immune systems weakened. In fact, the only factor associated with melanoma risk was exposure to the sun.
But the researchers did find some evidence that Merkel cell carcinoma and appendageal carcinomas were more common in people with weak immune systems. The researchers think that their results “suggest a need for guidelines aimed at the prevention and early detection of skin cancers in HIV-infected individuals”.
Yellow fever vaccine for people with HIV
Yellow fever is a potentially serious virus that is endemic in some parts of the world. Visitors to such regions are often required to be vaccinated against the virus.
Because the yellow fever vaccine is ‘live’ there had been some concerns that it wasn’t safe for people with HIV.
However, Swiss researchers have now found that the vaccine is safe for people with HIV. They found no evidence at all that it caused serious illness in people with HIV.
There results also showed, however, that people with HIV were more likely than HIV-negative people to quickly lose the protection the vaccine offers.
Researchers have also found a potential interaction between the anti-HIV drug maraviroc (Celsentri) and the yellow fever vaccine.