Thanks to earlier diagnosis and improvements in antiretroviral therapy, life expectancy for people treated for HIV infection
has gone up by more than 15 years in the UK since the mid-90s, according a study reported in the BMJ yesterday.
However, an accompanying editorial says the survival figures, which are some 13 years less than for the UK population as a
whole, are still not good enough.
Academics at the University of Bristol and University College London (UCL), led the Medical Research Council (MRC)-funded research.
They used data from the UK Collaborative HIV Cohort (UK CHIC) study on over 17,500 patients who started antiretroviral therapy between 1996 and 2008 at HIV clinics throughout the UK and compared their life expectancy with that of the UK population.
Lead author Dr Margaret May, Senior Research Fellow at Bristol's School of Social and Community Medicine, told the press their findings "strongly support" the idea of more widespread testing for HIV.
Before this, few studies had looked at how long people with HIV in the UK were likely to live.
For their calculations, May and colleagues estimated how many additional years after the age of 20 an HIV-positive person in the UK is likely to live.
The patients they included had CD4 cell counts of up to 350 cells/mm3 when they started their antiretroviral therapy.
They found that:
- Of the 17,661 patients eligible to be included in the analysis, 1,248 died during the follow up, which covered the equivalent of 91,203 person years.
- For male and female patients overall, life expectancy at 20 years old went up from 30.0 (standard error SE, 1.2) to 45.8 years (SE 1.7), from 1996-99 to 2006-08.
- There was a marked difference between women and men, a much wider gap than in the general population.
- For male patients the increased life expectancy was only 39.5 (0.45) years, while for females it was 50.2 (0.45) years.
- This compares with a life expectancy at age of 20 of 57.8 and 61.6 years respectively in the general population over the same period (1996-2008).
- Starting antiretroviral therapy later than guidelines suggest, resulted in up to 15 years of lower life expectancy.
- For patients who started when their CD4 count was 200-350, their life expectancy was 53.4 (SE 1.2) years; for patients with CD4 count 100-199 it was 41.0 (2.2); and for patients with CD4 counts below 100 it was 37.9 (1.3).
"Our research has found life expectancy in the HIV-positive population has significantly improved in the UK. We should expect further improvements for patients starting antiretroviral therapy now with improved modern drugs and new guidelines recommending earlier treatment."
They also point out there is a need to identify HIV-positive people early, before their CD4 levels get too low, "to avoid the very large negative impact this has".
The survival rates for HIV have improved such that compared with the general population, the risk of death in HIV-positive patients who undergo treatment successfully is about the same as people who live unhealthy lifestyles (for example heavy smokers, heavy alcohol consumers, and obese people), or who have chronic diseases such as diabetes.
Co-author Dr Mark Gompels, a lead clinician at North Bristol NHS Trust, said:
"These results are very reassuring news for current patients and will be used to counsel those recently found to be HIV- positive."
"It is also of clear benefit to patients to have the prognosis made in terms of their life expectancy and this might have considerable impact on patients' uptake of testing."
There are about 80,000 people infected with HIV in the UK, and estimates suggest about 1 in 4 does not realize it.
HIV (the human immunodeficiency virus) attacks the immune system, undermining its natural defence against disease and increasing the risk of developing a serious infection or disease, such as cancer.
It invades CD4 cells that live in the blood and fight infection. Once the virus enters the cell, it sets about destroying it, using the cell's resources to fuel its own replication. Although the body tries to make more cells to compensate, the virus eventually outpaces this, and the immune system seizes up. By stopping HIV from replicating, antiretrovirals help increase CD4 cells, thereby restoring the immune system.
Written by Catharine Paddock PhD