UK researchers found that the life expectancy of these patients improved significantly between 1996 and 2008, and that earlier diagnosis and timely treatment can increase life expectancy.

HIV infection has become a chronic disease with a good prognosis if treatment begins sufficiently early in the course of the disease and the patient sticks to antiretroviral treatment. However life expectancy for people with the disease is lower than that of the general population.

Researchers led by Dr Margaret May of the University of Bristol's School of Social and Community Medicine set out to estimate life expectancy of people treated for HIV infection and compare it with that of the UK general population.

They used data from the UK Collaborative HIV Cohort (UK CHIC) study, which in 2001 began collating routine data on HIV positive people attending some of the UK's largest clinical centres since January 1996.

Patients included in the analysis were aged 20 years and over and started treatment with antiretroviral therapy with at least three drugs between 1996 and 2008.

The researchers studied data on 17,661 patients, of whom 1,248 (7%) died between 1996 and 2008.

Their analysis shows that life expectancy for an average 20-year-old infected with HIV increased from 30 years to almost 46 between the periods 1996-9 and 2006-8.

The findings also show that life expectancy for women treated for HIV is ten years' higher than for men. During the period 1996 -2008, life expectancy was 40 years for male patients and 50 years for female patients compared with 58 years for men and nearly 62 years for women in the general UK population.

The point at which a person started treatment had an impact on their life expectancy, as the researchers also found that starting antiretroviral therapy later than guidelines suggest, resulted in up to 15 years loss of life.

Doctors use a test to count the number of CD4 cells in one cubic millimetre of blood. A normal CD4 count in a healthy, HIV-negative adult is usually between 600 and 1,200 CD4 cells/mm3.

The researchers found that life expectancy was 38 years, 41 years and 53 years in those starting antiretroviral therapy with CD4 counts less than 100, 100-199 and 200-350/mm3 cells respectively.

The improvement in life expectancy since 1996 was likely to be due to several factors, they say, including a greater proportion of patients with high CD4 counts, better antiretroviral therapy, more effective drugs, and an upward trend in the UK population life expectancy.

They conclude: "Life expectancy in the HIV-positive population has significantly improved in the UK between 1996 and 2008 and we should expect further improvements for patients starting antiretroviral therapy now with improved modern drugs and new guidelines recommending earlier treatment.

"There is a need to identify HIV-positive individuals early in the course of disease in order to avoid the very large negative impact that starting antiretroviral therapy at a CD4 count below 200 cells/mm3 has on life expectancy."

Dr Mark Gompels, lead clinician and co-author, 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."

In an accompanying editorial, researchers in Boston argue that, although these gains are encouraging, they have not been seen in everyone with HIV.

Nevertheless, this study "serves as an urgent call to increase awareness of the effectiveness of current HIV treatments in patients and providers," they say. "In turn this should increase rates of routine HIV screening, with timely linkage to care and uninterrupted treatment. As these factors improve, the full benefits of treatment for all HIV infected people can be realised."

Note: If no author is given, the source is cited instead.

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