This open access review paper on the characteristic changes of aging that occur in lung tissue and function illustrates the importance of immune system decline as a component of the frailty of aging. It impacts all of the major organs. Reversing the structural issues that cause much of the decline in immune response would be an early quick win in the development of human rejuvenation, and the necessary therapies - such as targeted destruction of unwanted immune cells, and replacement with cells grown from the patient's stem cells - could be implemented independently of all of the other necessary line items in a rejuvenation toolkit, and implemented within the next couple of years with no great advances in the state of the art:
There are many age-associated changes in the respiratory and pulmonary immune system. These changes include decreases in the volume of the thoracic cavity, reduced lung volumes, and alterations in the muscles that aid respiration. Muscle function on a cellular level in the aging population is less efficient. The elderly population has less pulmonary reserve, and cough strength is decreased in the elderly population due to anatomic changes and muscle atrophy. Clearance of particles from the lung through the mucociliary elevator is decreased and associated with ciliary dysfunction.
Many complex changes in immunity with aging contribute to increased susceptibility to infections including a less robust immune response from both the innate and adaptive immune systems. Considering all of these age-related changes to the lungs, pulmonary disease has significant consequences for the aging population. Chronic lower respiratory tract disease is the third leading cause of death in people aged 65 years and older.
With a large and growing aging population, it is critical to understand how the body changes with age and how this impacts the entire respiratory system. Understanding the aging process in the lung is necessary in order to provide optimal care to our aging population. This review focuses on the nonpathologic aging process in the lung, including structural changes, changes in muscle function, and pulmonary immunologic function, with special consideration of obstructive lung disease in the elderly.