We’re all getting older
HIV is often thought of as a disease the predominantly affects younger people.
This is gradually changing – HIV treatment is helping people diagnosed with the infection in their 20s and 30s live longer, healthier lives. Indeed, I was diagnosed shortly after my 24th birthday and will be 40 – an age I never expected to reach in the first few years after my diagnosis – in a few weeks.
There has also been an increase in the number of new diagnoses in recent years in older patients.
A study reported in this edition of HIV Weekly shows that although HIV treatment works well in people who are older, some side-effects occur more frequently in older patients. Some of these side-effects, such as increased blood fats and sugars, are associated with an increased risk of heart disease and other cardiovascular illnesses which occur more frequently in older age, and therefore need to be taken very seriously.
The doctors who conducted the study recommend that HIV treatment for older patients should have a section of its own in HIV treatment guidelines. This seems to make good sense – ageing involves a whole new set of health issues and these need to be considered within the context of HIV.
Viral load and CD4
The amount of HIV in the blood is measured using a viral load test. The higher your viral load, the faster your CD4 cell count falls and the greater your risk of becoming ill because of HIV.
Soon after a person is infected with HIV – a period often called primary infection - their viral load increases to very high levels, often leading to a massive drop in their CD4 cell count. Although viral load then falls back, most people’s CD4 cell count never recovers to the level it was before they were infected with HIV.
The way that humans respond to infections can evolve over a period of time. The term used to describe this is a disease’s ‘natural history.’ For example, it is known that the natural history of syphilis has changed dramatically over the last five hundred years – when the infection was first recognised in Renaissance Europe it caused very severe symptoms, often leading to a rapid death. Now, however, its symptoms are much milder and although infection with syphilis can still be fatal if untreated, it takes decades for this stage of the disease to be reached.
Researchers want to know if the natural history of HIV is changing. In a recent study they looked at the viral load and CD4 cell count of thousands of people being monitored in 22 large research projects between 1985 and 2002. The researchers wanted to see if there was any change over time in viral load and CD4 cell count at the time of HIV seroconversion.
They found that initial CD4 cell count fell by around 6 cells/mm3 per year and that viral load was increasing by an average of 11% per year.
The researchers conclude that their findings may “point towards changes in…the circulating virus over time” and have called for further studies to see “how repeatable and geographically widespread this finding is.”
Nutritional supplement has benefits
Many people with HIV choose to take nutritional supplements in the hope of strengthening their immune system, or promoting the effectiveness of HIV treatment, or lessening the side-effects of anti-HIV therapy or other medical treatment.
Generally, it is thought that people with HIV do not need any additional nutritional supplementation if they have a good, balanced diet.
But a body of evidence is now emerging that some vitamin and mineral supplements can be a useful addition to HIV treatment, and a study has been published showing that a daily selenium dose of 200μg is associated with a lower viral load and higher CD4 cell count in people who are either not taking anti-HIV therapy or are taking anti-HIV treatment but still have a detectable viral load.
The study involved 262 adults with HIV and was conducted at the University of Miami. The people were randomised to take either selenium everyday or a dummy placebo pill. The study is planned to last for 18 months and viral load, CD4 cell count and the amount of selenium in the blood are being monitored. Interim nine-month results have been published by the researchers.
An increase in the amount of selenium in the blood was found to be associated with a significant fall in viral load and a significant increase in CD4 cell count.
The researchers believe that selenium has an effect on viral load independent of HIV treatment. They speculate that the mineral might either reduce oxidative stress, therefore reducing HIV replication, or might have a direct impact on the ability of HIV to reproduce.
HIV and ageing
Older age has long been associated with shorter survival and faster disease progression in HIV-positive people.
Italian researchers conducted a study to see how effective HIV treatment was in a group of older patients, with an average age of 59, and a group of younger patients, with an average age of 30. The amount of side-effects and metabolic complications experienced by younger and older patients were also compared.
They found that a year of anti-HIV treatment produced a similar fall in viral load and a comparable increase in CD4 cell count in older and younger patients.
However, older patients were much more likely to experience an increase in their blood fats and sugars - cholesterol, triglycerides and glucose – than younger patients. This can increase the risk of heart disease and other cardiovascular illnesses.
Older patients were also more likely than younger patients to experience bone marrow side-effects and peripheral neuropathy.
New illnesses, including mental health problems and cardiovascular disease, also occurred more frequently in older patients.
Younger patients, however, were more likely to experience liver problems, but this was probably because many more younger patients than older patients were coinfected with hepatitis C virus.
“Older HIV-infected persons…constitute, in our opinion, a subgroup of patients for whom specific considerations are critical for the appropriate selection and monitoring of safe and effective antiviral treatment”, conclude the researchers.
HIV and the liver
Liver disease is now one of the major causes of illness and death in people with HIV. Much of this is caused by coinfection with hepatitis B virus and/or hepatitis C virus. Other causes can include recreational drugs or alcohol, insulin resistance or the side-effects of medicines used to treat HIV and other infections.
In some people, however, the cause of liver disease is unknown and doctors describe these cases as “cryptogenic” – of unknown origin.
Now doctors in Paris have found that about 8% of HIV-positive patients with liver disease had a rare, but potentially fatal illness called nodular regenerative hyperplasia. Symptoms included a build up of blood pressure in the vein connecting the liver with the stomach, bleeding into the stomach causing vomiting of blood and black stools, blood clots in the liver, and changes in the structure of the liver.
None of the patients treated by the doctor in Paris died because of nodular regenerative hyperplasia, but some are awaiting a liver transplant.
The doctors in Paris speculate about the causes of the condition, suggesting a possible role for HIV, or the side-effects of anti-HIV drugs.
HIV and hepatitis C
Some HIV-positive people who are coinfected with hepatitis C do not have hepatitis C antibodies.
A large study has looked for reasons why this might be the case.
It found that a history of injecting drug use, a low CD4 cell count (below 200 cells/mm3) and abnormal liver function were all associated with an absence of hepatitis C antibodies.
They study’s authors recommend that HIV-positive patients who had these characteristics should have hepatitis C viral load tests to see if they are infected with the virus.