Abstract and Introduction
Abstract
Purpose of review: This review seeks to inform readers of evolving concepts of ageing-associated risks for developing interstitial lung disease (ILD) and current approaches to the diagnosis and management of ILD in elderly patients.
Recent findings: Various aspects of cellular and immune senescence have been identified that may explain the increased susceptibility of the elderly to developing fibrotic lung disease. New guidelines have been recently published concerning the diagnosis and management of idiopathic pulmonary fibrosis (IPF), which is highly prevalent in elderly patients. Nontransplant therapies that can have a significant impact on disease progression for patients with IPF have yet to be identified. Additionally, evidence is accumulating that abnormal gastroesophageal reflux and microaspiration may play a role in IPF pathogenesis.
Summary: High-resolution computed tomographic scanning of the thorax can play a key role in making a specific ILD diagnosis and be used to make a confident diagnosis of various forms of ILD, especially IPF, when combined with a consistent clinical presentation. Management of ILD in the elderly should be not only disease specific but potentially therapeutic, and supportive interventions should be tailored to each individual patient and not entail significant risk of adverse complications, especially for the frail elderly patient.
Introduction
Advanced age is associated with declining organ system function that occurs as part of the natural aging process, and some elderly individuals are predisposed to developing accelerated physiologic decline with decreased reserve that compromises their ability to respond to stressors, a condition that has been termed frailty. Significant anatomic and histologic changes commonly affect the aged lung and alter physiologic function. These include airspace dilatation, a loss of static elastic recoil, and alterations in lung matrix that lead to increased lung compliance and a decline in forced expiratory flows and the FEV1/forced vital capacity (FVC) ratio. Additionally, lung function can be affected by changes in the chest wall (altered costovertebral articulations, narrowing of intervertebral disk spaces, altered chest wall contour) and a decline in respiratory muscle strength. Ageing is also associated with sarcopenia (decreased muscle mass and strength), which has been correlated with increased risk of developing functional impairment and disability.
Along with the predisposition to develop frailty, sarcopenia, and a decline in organ system function, the aging process is also accompanied by ageassociated changes in immunity that are linked to an increased susceptibility to develop infections, neoplasms, chronic inflammatory disorders such as rheumatoid arthritis (RA) and impaired ability to regulate inflammatory responses. Additionally, low-grade inflammatory changes in bronchoalveolar lavage (BAL) fluid have been reported in seemingly normal, elderly patients. However, there is considerable inter-individual variability in the extent and tempo of age-related physiologic decline and altered immunity. Some centenarians have been shown to have well preserved immune responses despite the general decline in immune function that is associated with advancing age. In contrast, certain immune response signatures (e.g. low numbers of CD4 T cells and CD19 B cells plus impaired T-cell proliferative response and increased numbers of CD3 cytotoxic/suppressor cells) have been associated with frailty and shortened lifespan, and another immune signature, downregulation of CD28 on circulating CD4 T cells, is associated with worse outcomes in patients with idiopathic pulmonary fibrosis (IPF).
Elderly individuals are at increased risk to develop age-associated forms of interstitial lung disease (ILD), such as IPF and ILD associated with connective tissue disease (CTD), but they may also develop other forms of ILD that can occur at any age. This article will review recent developments in our understanding of ILD and pulmonary fibrosis and focus on emerging concepts in the management of ILD in the elderly patient with an emphasis on the diagnosis and treatment of IPF.