More good HIV survival news, this time from a cohort study conducted in the United Kingdom. Whereas a 35-year-old person living with HIV between 1996 and 1999 could expect to live an additional 20 years, revised estimates for 35-year-olds living with HIV between 2006 and 2008 suggest 31 additional years of life expectancy.

In effect, Margaret May, PhD, of the University of Bristol School of Social and Community Medicine and her fellow UK Collaborative HIV Cohort (UK CHIC) study authors write in an October 11 British Medical Journal report, people with HIV have a life expectancy that’s 15 years longer thanks to improved treatments over the past 13 years.

UK CHIC, started in 2001, began collating routine data on people living with HIV attending some of the United Kingdom’s largest clinical centers since January 1996. Patients included in the current analysis were 20 years old and older 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 percent) died between 1996 and 2008.

Their analysis shows that life expectancy for an average 20-year-old infected with HIV increased from 30 years in 1996 to 1999, to almost 46 years in 2006 to 2008. In other words, a 20-year-old living with HIV could expect to live to be about 66 years old.

As for the increased life expectancy calculated for 35-year-olds, this translated into an average lifespan of 75 years.

The authors did note important gender differences. Essentially, May and her colleagues found that life expectancy for women treated for HIV is 10 years greater than that for men. During the period 1996 to 2008, life expectancy for a 20-year-old was 40 years for males living with HIV and 50 years for females living with HIV, compared with 58 years for men and nearly 62 years for women in the general U.K. population.

The CD4 count at which a person started treatment did have an impact on his or her life expectancy, May’s group found. Life expectancy was 38 years, 41 years and 53 years among those starting antiretroviral therapy with CD4 counts less than 100, between 100 to 199 and between 200 to 350 cells, respectively.

Life expectancies for people starting therapy with CD4s above 350 were not calculated.

The improvement in life expectancy since 1996 was likely due to several factors, May and her colleagues write, including a greater proportion of patients with high CD4 counts, better antiretroviral therapy, more effective drugs, and an upward trend in the U.K. population’s life expectancy.

Though the life expectancy of people living with HIV in UK CHIC was still rougly 15 years shorter than that of the general UK population, some modifiable factors were listed as likely causes of this disparity. Non-adherence to treatment, treatment interruptions, the use of first-line regimens that are less robust than those currently available and delayed treatment, a history of low CD4 counts or AIDS-definining illnesses and a variety of lifestyle factors--such as smoking, drug misuse and alcohol abuse--were among the possible reasons for poorer survival among the study volunteers living with HIV.

“Life expectancy in the HIV-positive population has significantly improved in the [United Kingdom] 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,” the authors conclude.

“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 has on life expectancy,” they add.