Antiretroviral Therapy Response and Life Expectancy

The life span for some groups of HIV-infected patients receiving combination antiretroviral therapy (cART) may now be similar to that of the population at large. However, the timing of initiation of cART has a significant impact on life expectancy, with shorter life spans recorded for patients who receive a late diagnosis and so a delayed introduction to cART.¹

A recent study published in the journal AIDS² examined the improvement in life expectancy associated with CD4+ cell count recovery and viral suppression in patients receiving cART. Investigators analyzed data from the UK Collaborative HIV Cohort Study including HIV-positive individuals in care in the UK between 2000 and 2012. The study enrolled patients aged 20 years or older, who started treatment with cART with at least 3 drugs between January 1, 2000, and December 31, 2010.² The group was followed for mortality until December 31, 2012. The investigators excluded patients assumed to have become infected through injection drug use or mother-to-child transmission. CD4+ cell counts and viral load data were collected.²

The study included 21,388 eligible HIV-positive individuals who started cART between 2000 and 2010. Of these patients, 961 (4.5%) died over 110,697 person-years.² There was a graded association between expected age at death and attained CD4+ cell count and status of viral suppression. Patients who began therapy with low CD4+ cell counts had a significantly improved life expectancy if they achieved a good CD4+ cell count response and undetectable viral load.² For example, a 35-year-old man with a CD4+ cell count less than 200/μL could expect to live until age 71 (68 to 73) years, a life expectancy more than 7 years less than men in the general UK population. If the same patient increased his CD4+ cell count in the first year of cART to at least 350/μL and achieved viral suppression, life expectancy would increase by 10 years, to age 81 (77 to 84) years, which is comparable with the life expectancy for men in the general population.² The study authors found that when CD4+ cell count is stratified, expected age at death is higher for those patients with than those without viral suppression within each level.²

This study shows that longevity in HIV-infected patients is dependent on both CD4+ cell count restoration and achieving viral suppression to undetectable levels. Achieving these milestones was associated with life expectancy similar to that of the general population.²

References:

1. Hogg R, Lima V, Sterne JA, et al; Antiretroviral Therapy Cohort Collaboration. Life expectancy of individuals on combination antiretroviral therapy in high-income countries: a collaborative analysis of 14 cohort studies. Lancet. 2008;372:293–299. doi:10.1016/S0140-6736(08)61113-7.

2. May MT, Gompels M, Delpech V, et al; UK Collaborative HIV Cohort (UK CHIC) Study. Impact on life expectancy of HIV-1 positive individuals of CD4+ cell count and viral load response to antiretroviral therapy: UK cohort study. AIDS. 2014;28:1193-1202.  Published online 2014 Apr 29. doi:10.1097/QAD.0000000000000243.