A 20-year-old HIV-positive person starting antiretroviral (ARV) therapy today can expect to live, on average, to the age of 69, according to new calculations published July 26 in The Lancet. The study authors say this is a life expectancy increase of 37 percent over projections for 20-year-olds starting ARVs during the early years of combination treatment.

HIV-positive people have frequently asked their health care providers how long they will live with the virus, especially with so many effective ARV options to choose from. Few studies have attempted to answer this question-until now.

To determine life expectancy among HIV-positive patients, an international roster of researchers joined forces and reviewed the medical records of more than 43,000 people living with the virus in the United States, Canada and several European countries. The study participants were split into three groups: 18,587 people who started ARV treatment between 1996 and 1999, 13,914 who started treatment between 2000 and 2002, and 10,854 people who started treatment between 2003 and 2005.

The researchers predicted that a 20-year-old person starting ARV treatment between 1996 and 1999, the early years of combination ARV therapy, could be expected to live an additional 36 years, to the age of 56. This increased significantly, however, as time passed. A 20-year-old who started treatment between 2003 and 2005 was expected to live an additional 49 years, to the age of 69.

The average life expectancy for a 20-year-old who remains HIV negative, at least in industrialized nations, is an additional 60 years—with death occurring, on average, at the age of 80.

HIV-positive people who didn’t start ARV treatment until their CD4s dropped to 100 were expected to live 10 fewer years than people who started therapy when their CD4s were above 200. The authors also determined that HIV-positive people with a history of injection drug use were expected to live 10 fewer years than those who never used injection drugs.

In a letter in The Lancet commenting on the study, David Cooper, MD, from the University of New South Wales in Sydney, questions whether starting ARV treatment even earlier, at a CD4 count above 500 for instance, may bring life expectancy even closer to normal. Dr. Cooper hopes that the international Strategic Timing of Anti-Retroviral Treatment (START) clinical trial, which is investigating earlier initiation of ARV treatment, will provide the answer.

Results from a larger European study, reported at the 17th Conference on Retroviruses and Opportunistic Infections (CROI) in February 2010, also suggest ’near normal’ survival among people living with HIV who keep their CD4 counts above 500 cells for at least three years.