Chronic inflammation and increased immune responses are considered major causes in premature ageing, frailty and other age-associated disease in HIV positive individuals. Early diagnosis and treatment are, therefore, key to delaying the premature aging often noted in people with long-term HIV disease.
“Premature Senescence (Premature Aging) – HIV/AIDS
Updated April 01, 2014
Definition: Premature senescence is the biological aging of an individual at a time much earlier than expected or experienced in the general population.
Roughly speaking, aging is characterized by the body’s decreased ability to face stresses, making it more difficult to maintain biological stasis (equilibrium), while increasing the risk of aging-associated diseases like Alzheimer’s or metabolic bone disorders. Premature senescence (also known as premature aging) suggests that the body is aging “well before its time” and can usually be linked to one or several causal agents or events.
Normal aging is associated with chronic, low-grade inflammation—known as “inflammaging”—which plays a role in the slowing of cellular growth, as well as the gradual loss of tissue function. The mechanics of aging are considered, by and large, inevitable, although genetic, environmental and age-related factors can determine an individual’s vulnerability to aging and death.
By contrast, premature senescence is associated with chronic inflammation which is greater than that experienced in the average, healthy individual. This elevated level of persistent inflammation can cause accumulative damage on a cellular and molecular level, placing cells under an oxidative stress to where they are less able to detoxify the body or repair damage.
Inflammation can cause direct damage to genes to where the genetic coding of cells altogether changes—resulting often in cell death or the development of cancerous mutations. In time, the affected cells stop dividing altogether, and the body as a whole literally ages.
Premature senescence can be caused by certain infections, as well as behavioral factors such as smoking and obesity, or environmental factors such as pollutants or radiation.
Premature Senescence and HIV Infection
HIV infecion is characterized by long-term immune activation, wherein the body responds to the presence of the virus by producing defensive antibodies and proinflammatory proteins. The increased immune activation and persistent, chronic inflammation associated with HIV are considered major players in the aging process, resulting in premature frailty and aging-associated diseases.
As an example, non-AIDS related cancers are today considered the leading cause of death for HIV-infected people in the developed world, with most being diagnosed 10-15 years earlier than their non-infected counterparts. Similarly, the neurocognitiveiimpairment often associated with aging are seen in people with long-term HIV at a median age of 46, while the median age for myocardial infarction (heart attacks) stands at a mere 49 years—seven to 16 years earlier than uninfected men and women.
Moreover, even when HIV is well controlled by way of combination antiretroviral therapy (cART), HIV-infected people are more prone to the early appearance of aging-associated illness, albeit at a significantly lower rate.
Patients with early cART and a high CD4 nadir are generally seen to be under lesser burden of chronic inflammation than those who start treatment late, while patients with sustained viral control are considered less vulnerable to age-related comorbidities than individuals who are either untreated or unable to achieve viral suppression.
Early diagnosis and treatment are, therefore, key to delaying the premature aging often noted in people with long-term HIV disease. “
Posted by Stella Heuer
April 4, 2014