Fast Five Quiz: Progressive Fibrosing Interstitial Lung Disease

Zab Mosenifar, MD, FACP, FCCP


April 12, 2022

NSIP is the most common manifestation of collagen vascular disease in the lung and may precede the diagnosis of collagen vascular disease by months or even years. It has been associated with exposure to various drugs.

NSIP is a relatively common manifestation of polymyositis/dermatomyositis, progressive systemic sclerosis, and mixed connective tissue disease. While other patterns of lung involvement have been described more commonly in rheumatoid arthritis, systemic lupus erythematosus, and Sjögren syndrome, NSIP pattern has also been identified. The NSIP pattern can also be seen in patients with hypersensitivity pneumonia or who have had recent acute lung injury.

The etiology of IPF remains undefined; however, current theories are that exposure to an inciting agent (eg, smoke, environmental pollutants, environmental dust, viral infections, gastroesophageal reflux disease, or chronic aspiration) in a susceptible host may lead to the initial alveolar epithelial damage. This damage may lead to activation of the alveolar epithelial cells, which provokes the migration, proliferation, and activation of mesenchymal cells with the formation of fibroblastic/myofibroblastic foci, leading to the exaggerated accumulation of extracellular matrix with the irreversible destruction of the lung parenchyma.

Systemic sclerosis is an autoimmunologic disease, but the pathogenesis is only partially understood. Certain factors are well known to trigger occurrence of the disease or create a similar clinical appearance.

HP, or extrinsic allergic alveolitis, is an inflammatory syndrome of the lung caused by repetitive inhalation of antigenic agents in a susceptible host. The syndrome varies in intensity, clinical presentation, and natural history depending on the inciting agent, as well as the intensity of exposure. In most cases, disease can be reversed with prompt diagnosis followed by identification and removal of exposure risks. As such, prognosis is generally very good. More than 300 etiologies of HP have been reported from a wide range of exposures involving airborne antigens.

Learn more about the etiology NSIP.


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