Interstitial Lung Disease Flashcards
Interstitial Lung Disease
Heterogeneous group of diseases characterized by acute, subacute, or chronic infiltration of the interstitium of the lungs by fluid, cells, and connective tissue components.
Two most common interstitial lung disease
Idiopathic Pulmonary Fibrosis
Idiopathic nonspecific interstitial pneumonia
Pulmonary function tests associated with interstitial lung disease?
Restrictive physiology and impaired gas exchange. Decrease FVC and TLC, preserved FEV/FVC ratio, decreased DLCO, increased A-a gradient.
Some classic radiographic manifestations of ILD
Traction bronchiectasis, reticular densities, honeycombing, cysts.
Inflammatory process will have ground glass opacities and consolidation
Interstitial Pulmonary Fibrosis Histopathology pattern?
Usual interstitial pneumonia.
Median survival for IPF?
2.8 years. 90% mortality in the ICU
Clinical features of IPF?
Subacute or chronic illness, insidious onset of dyspnea. Cough, rales, restrictive PFTs. Decreased DLCO decreased A-a gradient.
Radiology of Idiopathic pulmonary fibrosis?
Densities at the bottom of the lungs. Begins near the plura and moves inwards.
Usual interstitial pneumonia
Histopathologic pattern of idiopathic pulmonary fibrosis.
Fibroblast focus
Confirms UIP histopathology.
Pathogenesis of IPF
Cell death and impaired reepithelialization. This causes basement membrane damage, leading to the release of growth factors and other products of epithelial cell injury. These growth factors impair repithelialization and cause proliferation of myofibroblasts that do not undergo apoptosis. These fibroblasts cause collagen and matrix remdeling. Finally vascular remodeling too.
Genetics of IPF?
25% of patients with IPF have family members with interstitial lung disease. Autosomal dominant pattern of inheritance.
Factors associated with decreased survival of IPF
Pulmonary hypertension, low DLCO, decrease in PFTs in 6 months. Fibroblast foci too
Two agents used in IPF therapy
Pirfenidone
Nintedanib
Pirfenidone
Blocks pro-fibrotic cytokines TGFB and PDGF
Nintedanib
Triple tyrosine kinase inhibitor (VEGF, fibroblastGF, PDGF)
Acute Interstitial Pneumonia
Catastrophic acute respiratory failure with DAD on pathology. Mimics ARDS with a very high mortality
Two smoking related interstital lung disease
Respiratory bronchiolitis interstitial lung disease, desquamative interstitial pneumonia
Nonspecific interstitial pneumonia
Better prognosis than usual interstitial pneumonia, associated with connective tissue disorders and drug use. Can be treated
Cryptogenic organizing pneumonia
Best prognosis of all, associated with connective tissue disorders and drugs.
Some connective tissue diseases
Systemic sclerosis (scleroderma) Rheumatoid Arthritis SLE Dermatomyositis Polymyositis Sjogren's Syndrome
Connective tissue disorder effect on parenchyma of lung
Inflammation, fibrosis, bleeding
CTD effect on airways
Bronchitis, bronchiolitis,bronchiectasis
Which CTD causes pleural effusions?
SLE
Can CTD’s cause UIP?
Yes
What CTDs are associated with nonspecific interstitial pneumonia
Scleroderma, polymyositis/dermatomyositis.
Fair prognosis
What drug can cause interstitial lung disease? How to treat?
Nitrofurantoin (which is used to treat UTIs), stopping drug can clear lungs
Sarcoidosis
Forms noncaseating granulomas result of an immunological response to an antigenic trigger. Affects multiple organs, lungs in >80%. Diagnosis of exclusion. Infections/noninfectious etiologies must be ruled out.
Staging of Sarcoid
0- normal 1-bilateral hilar lymphadenopathy 2 - bilateral hilar lymphadenopathy with bilateral infiltrates 3- just infiltrates 4- pulmonary fibrosis
