Interstitial lung disease II Flashcards
summary of hypersensitivity pneumonitis
type IV hypersensitivity (cell-mediated hypersensitivity) with many known exposures
acute, subacute, and chronic forms exist
path involves granulomatous peribronchiolar inflammation with CD8 lymphocytes
treat by removing offending agents. acute and subacute also respond to steroids.
etiology of hypersensitivity pneumonitis
non-IgE mediated immunologic/inflammatory lung disease from sensitization to organic dusts. may involve the immune complexes or cell mediated immunity. may begin as a type III sensitivity with Ab-antigent complexes deposited on walls but ultimately is a type IV rxn (lymphocytic and mononuclear cell infiltrate, esp. CD8 cells).
acute, subacute, and chronic hypersensitivity pneumonitis
acute: brief but intense exposure. looks like 24 hr flu
subacute: less intense, more prolonged exposure. chonic bronchitis and exertional dyspnea. less specific.
chronic: looks like chronic pulmonary fibrosis or end stage IPF from chronic long term exposure or as a sequelae of high level of exposure. chonic doesn’t respond to steroids.
radiology of hypersensitivity pneumonitis
poorly defined micronodules and widespread ground glass, esp. in upper and middle lung.
eosinophilic pulmonary syndromes summary
there are secondary and idopathic forms
no vasculitis
treatment is based on underlying cause
usually idiopathic form responds to steroids but chronic form relapses
many are associated with underlying disease
radiology for eosinophilic pulmonary syndromes
“photonegative of pulmonary edema”
diffuse peripheral infiltrates. usually bilateral with lobar/segmental distribution.
Churg-Strauss clinical presentation
3 stages:
- prodromal: allergey and asthma
- peripheral eosinophilia and tissue infiltration
- vasculitic phase: may be life-threatening
Churg-Strauss etiology
unclear precipitating factors.
pANCA positive necrotizing vasculitis: pANCA targets myeloperoxidases, which is a neutrophil granule protein
also associated with asthma and peripheral eosinohilia nad with leukotriene modifiers
Radiology for churg-strauss
peripheral reticulonodular opacities and ground glass
Pathology of churg strauss
granulomatous foci around arteries and veins with multinucleated giant cells.
Wegener’s granulomatosis: etiology and basic pathophysiology
small vessel systemic necrotising vasculitis. associated with cANCA (proteinase 3 target)
Wegener’s clinical triad
upper and lower nectroizing granulomas, generalized necrotizing vasculitis of arteries and veins in the lungs, and glomerulonephritis. often also see lower tract infections.
Wegener’s radiology
diffuse reticulo nodular infiltrates. subglottic stenosis and trancheobronchial stenosis
Wegener’s pathology
cellular infiltrate with alveolar hemorrhage. Wall of vessel is replaced by granulomatous inflammation, giant cells and chronic inflammatory cells
Good Pastures syndrome
attacks type IV collagen (type II hypersensitivity)
linear deposition of anti-glomerular basement membrane antibodies
40% have pANCA
classically in men in 20s with lung hemorrahge and glomerular necrosis
