ABSTRACT
Advancing age is associated with a decline in the integrity of physical barriers and
protection against invading pathogens, and age-related changes in the immune system
are associated with increased susceptibility to the emergence of autoimmune phenomena,
neoplasia, and infections. Respiratory tract infections can occur at any age, but
the incidence of lower respiratory tract infections increases significantly with advanced
age such that pneumonia is a leading cause of illness and death in the elderly. Changes
in lung physiology and immune function coupled with inflammation induced by environmental
exposures or endogenous factors such as predisposition to aspiration may, in part,
account for the increase in susceptibility to respiratory infections. Additionally,
age-associated alterations in immune regulation (“immunosenescence”) with dysregulation
of lung homeostasis may allow low-grade inflammatory changes that lead to anatomical
and physiological changes that characterize the senescent lung. The presence of disease
states in elderly populations, such as chronic obstructive pulmonary disease (COPD)
or nonpulmonary organ system diseases, may increase the likelihood of developing severe
respiratory infections. This article examines age-related changes in immune function
that predispose elderly individuals to lung remodeling but focuses especially on lower
respiratory tract infections. It will discuss risk factors, identify pathogens that
typically lead to respiratory infections in the elderly, and review current approaches
to treatment and prevention of respiratory infections in the elderly population.
KEYWORDS
Lung - aging - aged - elderly - pneumonia - immunosenescence - immunity
REFERENCES
The aging human lung: age-associated changes in structure and function . In: Conn PM Handbook of Models for Human Aging. Boston, MA; Elsevier Academic 2006:
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kcm@medicine.wisc.edu
