Interstitial Lung Disease I Flashcards
- Describe the classification of interstitial lung diseases.
idiopathic interstitial pneumonias (idiopathic pulmonary fibrosis)
dysregulated inflammatory responses: granlomatous disorders (sarcoidiosis), ILD associated with connective tissue disorders, eosinophilic pneumonias, alveolar hemorrhage syndromes
injurious exposures: occupational/environmental/inhlational (asbestosis), iatrogenic pneumonitis/fibrosis
inherited disorders
misc.
- Identify the pathologic characteristics of various interstitial lung diseases, including patterns of lung inflammation, injury and repair.
variable degrees of injury, inflammation and fibrosis within the parenchyma, resulting in accumulation of inflammatory cells and connective tissue within the alveolar interstitium with remodeling
common histological patterns include granulomatous inflammation, IPF/UIP and asbestosis; fibrosis can often follow a pattern of wound healing including inflammation and scar formation (fibrosis)
overall changes in lung capacity and decreased diffusion capacity
- Summarize the symptoms common in interstitial lung diseases.
dyspnea (progressive) and to a lesser degree cough (non productive except with bronchiectasis) are the most prominent symptoms; fatigue or malaise, pleurisy, or arthralgias may be present with CTD
inspriatory crackles prominent over lower lung fields, pleural friction rub with pleuritis with CTD or SLE
clubbing of digits common in some, eye involvement (sarcoid) and skin involvement possible, skin lesions or joint disease
- Illustrate radiologic findings characteristic of ILD patients.
interstitial infiltrative patterns or nodular pattern (granuloma) or reticular pattern (typical of fibrosis) on CXR
HRCT can be diagnostic demonstrating nodular densities along with bronchovascular bundles and hilar adenopathy (sarcoid) or sub pleural reticular densities aka honeycomb change in usual interstitial pneumonia (IPF)
ground glass suggestive of active inflammation whereas extensive honeycombing reflects end-stage fibrosis
- Demonstrate the pulmonary function test patterns that are associated with pulmonary fibrosis and demonstrate the physiologic basis for this pattern, particularly why lung volumes, lung compliance and diffusion capacity may be abnormal.
restrictive physiological changes observed, distribution of ventilation is usually perturbed due to altered V/Q relationships, DLCO decreased on exertion (due to accumulating tissue) and chronic hyperventilation may be present
PFT can define disease severity but findings are non-specific and generally not diagnostic of a specific disease
- Identify laboratory abnormalities that can aid in the diagnosis of interstitial lung disease (Especially in the diagnosis of connective-tissue associated ILD).
ANA is suggestive of CTD: rheumatoid arthritis, scleroderma, polymyositis, SLE
Abnormalities of CCB, hepatic/renal function or uranlysis(elevated Ca++ or high eosinophil) can be diagnostic (antineutrophil cytoplasmic antibody in polyangiitis with granulamatosis or anti-blomerular basement antibody in Goodpasture’s syndrome)
- Recognize that bronchoscopy and surgical lung biopsies can assist in diagnosing ILD.
transbronchial lung biopsy: less invasive and less risky than surgical lung biopsy, but limited due to patchy disease *can detect sarcoidosis, lymphatic carcinoma, cryptogenic organizing pneumonia or hypersensitivity pneumonitis
bronchoalvolar lavage: not diagnostic but supportive of diagnosis- can detect blast, histo or TB on culture
surgical lung biopsy, VATS is better tolerated and usually yields adequate tissue, SLB performed if confident dx. cannot be reached by less invasive testing, useful in guiding therapeutic decisions and risk factors do no indicate high likelihood of serious complication
- Summarize the diagnostic algorithm for diagnosing ILD.
- medical history, PE and labs
- HRCT
- Bronchoscopy
- surgical lung biopsy
- Contrast pathologic features present in sarcoidosis to other forms of ILD
unlike TB has non-caseating granulomas
sarcoidosis often occurs in other organs (eye, heart, liver, bone, skin), some extra pulmonary involvement can be severe or life-threatening
granulomas volume can distort alveolar and interstitial architecture and granulomatous inflammation can lead to tissue damage and fibrosis with permanent pulmonary dysfunction
- Identify theories behind the etiology of sarcoidosis.
genetic factors undoubtedly play a role in susceptibility, specific HLA alleles have been linked to sarcoidosis and it can run in families
beryllium metal can induce a disease that is virtually indistinguishable from sarcoidosis
- Demonstrate clinical features typical of sarcoidosis.
usually effect people in 3,4, or 5th decade with subacute onset of symptoms and many are identified incidentally when evaluated for other medical problems
lungs are usually clear to auscultation unless associated fibrosis has occurred or bronchial hyperreactivity (wheeze)
skin may have sarcoid plaques or erythema nodosum (red raised lesions); anterior uveitis, retinitis, cardiac rhythm abnormalities, altered mental status or hepatosplenomeagaly
younger patients have grater chance of remission
- Illustrate common findings of sarcoidosis present on CXR, including staging.
- without involvement of lung (extra pulmonary sarcoid)
I. symmetrical, bilateral hilar adenopathy without radiographically detectable parenchymal abnormalities
II. hilar adenopathy with accompanying parenchymal infiltrates
III. parenchymal abnormalities without evidence of fibrosis and without hilar adeopathy.
IV. shows parenchymal changes with fibrosis
- Describe the clinical course of sarcoidosis.
patients need to be followed over time to determine disease activity and to rule out an alternative cause of granulomatous tissue inflammation
course is unpredictable, most with stage I do not progress to more severe involvement, some patients have chronic disease that may remain stable and some severe disease may progress to respiratory failure
some patients with liver transplant have shown multi organ regression
- Be aware of the treatment strategies in sarcoidosis.
- no tx. if min. disease
if progressive or significant extra pulmonary disease
- immunosuppressive therapies (corticosteriods or cytotoxic agents)
- immunomodulatory agents (anti TNF, thalidomide)
- lung transplant
- Describe the clinical features of idiopathic pulmonary fibrosis. Contrast this with other forms of ILD, such as sarcoidosis.
interstitial lung disease prevalent in older individuals (poor prognosis)
desquamative interstitial pneumonia (DIP), usual interstitial pneumonia (UIP) or non-specific interstitial pneumonia (NSIPS), note IPF (clinical diagnosis)= UIP (pathologic descriptor)
