HTB

Antiretrovirals calculated to extend life expectancy by 35 years

30 October 2008. Related: Antiretrovirals.

Simon Collins, HIV i-Base

An analysis from a large international cohort study from the Antiretroviral Therapy Cohort Collaboration (ART-CC) has calculated that antiretroviral treatment currently extends life expectancy for HIV positive people to an average of 65 years.

The model used patients who start treatment when either 20 or 35 years old.

Using data from 43,000 patients from 14 cohorts from Canada, Europe and the US, the researchers estimated the life expectancy since 1996 on the basis of reported deaths within the cohorts and compared rates in treatment-naive patients starting treatment in the 1996-99 period to patients starting treatment from 2003-05.

Compared to the earlier treatment group, life expectancy for patients starting treatment in 2003-05 increased by 13 years. Although life expectancy increased similarly in all groups there were significant absolute differences between different groups of patients.

Women had higher life expectancies than men (overall mortality rates/1000 patient years [95%CI]: 9.1 [8.2-10.1] vs 12.9 [12.3-13.6].

Patients with presumed transmission via injecting drug use had lower life expectancies than did those from other transmission groups (32.6 [±1.1] years vs 44.7 [±0.3], based on starting treatment aged 10).

Life expectancy was lower in patients with lower baseline CD4 cell counts than in those with higher baseline counts (32.4 [±1.1] years for CD4 cell counts below 100 cells/mm3 vs 50.4 [±0.4] years for counts of 200 cells/mm3 or more).

COMMENT

One of the most common responses to an HIV diagnosis, and one of the key unanswered questions even for long-term survivors, relates to life expectancy. It is therefore important to draw on the most recent studies to inform these discussions.

Antiretroviral therapy since 1996 has dramatically reduced mortality and extended life in all countries where there is access treatment, and as experience with treatment and availability of new and better drugs improves, projected life expectancy has similarly increased. Every few years a new study produce more optimistic figures – 12 years, 25 years and now 35 years in the latest studies. [1, 2] It likely that future studies will close the gap between HIV positive and HIV-negative populations.

But it we are not there yet. The paper from ATCC still shows 10-20 year differences due to HIV status. Patients starting at lowest CD4 levels have 10-20 years lower life expectancy and injecting drug use also impacts by 10 years.

ARV treatment, if used carefully, does not appear to have a built-in shelf life. Once virus is suppressed to below 50 copies/mL, ongoing viral evolution is stopped, rather than slowed, and resistance is related to poor adherence, or more rarely, re-infection with a resistant strain.

Experience with HAART over ten years suggests that initial concerns about compartmental sites, especially in relation to drug penetration and compartmental resistance has not led to systemic virological failure on a significant or measurable level. There are little data to predict whether this will become an important concern with longer use of treatment.

However, real concerns related to HIV-positive patients and ageing include the greater risks for neurological complications, brain disorders (including alzheimer’s and parkinsons), reduced bone mineral density, bone disease and fractures, virally-mediated cancers, diabetes, and heart disease.

The extent to which an extended period of uncontrolled viraemia prior to starting treatment may explain some of these increased risks is one of the questions addressed by several research groups, including the START study, due to enrol later this year. [3]

References

  1. The Antiretroviral Therapy Cohort Collaboration Life expectancy of individuals on combination antiretroviral therapy in high-income countries: a collaborative analysis of 14 cohort studies. The Lancet, Volume 372:293-299. (26 July 2008).
    http://www.thelancet.com/journals/lancet/article/PIIS014067360861113 7/abstract
  2. Lohse N et al. Survival of Persons with and without HIV Infection in Denmark, 1995-2005. Annals 2007 146: I-39.
    http://www.annals.org/cgi/content/abstract/146/2/87
  3. START protocol nearing final approval. INSIGHT News. February, 2008 http://insight.ccbr.umn.edu/newsletters/000/insight-news-february-2007.p df

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