Flashcards in The Lungs 2 Deck (87)
What is the "hallmark" of diffuse interstitial (restrictive/infiltrative) lung diseases?
Reduced lung compliance/increased stiffness
Diffuse interstitial (restrictive/infiltrative) lung diseases are characterized predominantly by diffuse and chronic involvement of the pulmonary __________ _______, principally the most peripheral and delicate interstitium in the ________ _______.
involvement of the pulmonary connective tissue in the delicate interstitium of the alveolar walls.
What two things are seen on CXR in a patient with diffuse interstitial (restrictive/infiltrative) lung disease?
1. Diffuse infiltration by small nodules.
2. Ground-glass shadows (irregular lines)
Diffuse interstitial (restrictive/infiltrative) lung disease eventually leads to diffuse interstitial _______ with or without _________.
interstitial fibrosis with or without honeycombing
What is the earliest, most common manifestation of diffuse interstitial (restrictive/infiltrative) lung disease?
If alveolitis is mild and self limited, can resolution and restoration of normal architecture be acheived?
Where exactly in the lungs do inflammatory and immune cells accumulate in the setting of alveolitis? Specifically which cells are involved?
Fibroblasts, lymphocytes, macrophages, and neutrophils are found within the alveolar walls and spaces
What is the key event in the pathogenesis to interstitial fibrosis from alveolitis?
Activation of pulmonary macrophages.
Once activated, what to macrophages do that contributes to the pathogenesis of chronic restrictive lung disease and fibrosis? (3 things)
What therefore happens to the pneumocytes?
1. They recruit neutrophils
2. They release oxidants and proteases (and so do the recruited neutrophils)
3. They release fibrogenic and chemotactic cytokines that activate fibroblasts
These factors injure type I pneumocytes and cause hypertrophy and hyperplasia of type II pneumocytes
Define idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis.
A type of restrictive lung disease of unknown etiology
Describe the general pathogenesis of idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis.
Repeated epithelial activation/injury --> abnormal repair --> increased fibroblast and myofibroblast proliferation --> fibroblastic loci
Which GF plays an important role in the pathogenesis of idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis? How does it work?
TGF-beta1 activates fibroblasts and myofibroblasts to make ECM stuff leading to fibrosis
What morphological change typifies idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis?
Patchy but progressive bilateral interstitial fibrosis.
The radiologic and histologic pattern of lung fibrosis is known as what?
Usual interstitial pneumonia (UIP)
Describe the two gross morphological changes seen in usual interstitial pneumonia.
Pleural surface has a cobblestone appearance due to retraction of scars along the interlobular septa.
Cut surface shows fibrosis (firm, rubbery white areas), especially in the SUBPLEURAL region of the lower lobes and along the CT septa.
Describe four histologic changes seen in usual interstitial pneumonia.
1. PATCHY INTERSTITIAL FIBROSIS interspersed with normal tissue.
2. Alveolar septal infiltration of mostly lymphocytes, occasional plasma cells, and occasional eosinophils.
3. Severe cases exhibit alveolar collapse due to dense fibrosis.
4. Cystic spaces are lined by hyperplastic type II pneumocytes or bronchial epithelium (known as honeycomb fibrosis).
What is the difference between early and late lesions in the lungs of a person with lung fibrosis and usual interstitial pneumonia?
Early lesions have lots of proliferating fibroblasts (fibroblastic loci).
Late lesions become less cellular and more collagenous.
Advanced cases of idiopathic pulmonary fibrosis result in severe ______ and ______.
hypoxemia and cyanosis
Is usual interstitial pneumonia a common type of interstitial pneumonia? Which gender is most often affected? How old are most people with the disease?
Yeah its a common type. Males > females. 2/3 of pts are over 60.
Name three clinical features of UIP.
1. Gradual dyspnea upon exertion.
2. Dry cough with velcro-like crackles during inspiration.
3. Cyanosis, cor pulmonale, and peripheral edema may develop in late stages.
What is the mean survival rate of UIP and what is the definitive treatment?
3 years or less. Tx is lung transplantation
Is pneumoconioses a restrictive, or obstructive lung disease?
What is pneumoconioses?
Non-neoplastic lung reaction to inhalation of crap.
Name three mineral dusts that can contribute to pneumoconioses.
1. Coal dust
What is the most important factor in the pathogenesis of pneumoconioses?
The capacity of the inhaled particulates to stimulate fibrosis.
What sized particles are most dangerous regarding the pathogenesis of pneumococonioses? Why?
1 to 5 micrometers (small ones) because they get lodged at the bifurcations of the distal airways
Which cellular component is key in the initiation and perpetuation of lung injury and fibrosis in the pathogenesis of pneumococonioses?
What is asbestosis?
A type of pneumococonioses: Diffuse interstitial fibrosis (restrictive) from inhalation of asbestos fibers.
Describe the pathogenesis of asbestosis.
Macrophages try to eat the asbestos fibers. Some fibers get into the interstitium. Macrophages get activated, and they activate firboblasts.