1
Q
Diffuse Interstitial Pneumonias–Essentials of diagnosis
A
- important to identify specific fibrosing disorders
- idiopathic dz may require biopsy for diagnosis
- Accurate Dx identifies its most likely to benefit from therapy
2
Q
Most common diagnosis among pts with diffuse interstitial lung disease is
A
-one of the interstitial pneumonias–UIP, RB-ILD, AIP, NSIP, COP
3
Q
Medication related Interstitial lung disease causes
A
- Antiarrythmic agents (amiodarone)
- Antibacerial agents (nitrofurantoin, sulfonamides)
- Antineoplastic agents (bleomycin, cyclophosphamide, methotrexate, nitrosoureas)
- Antirheumatic agents (gold salts, penicillamine)
- Phenytoin
4
Q
Environmental and occupational (inhalation exposures) interstitial lung disease causes
A
- Dust, inorganic (asbestos, silica, hard metals, beryllium)
- Dust, organic (thermophilic actinomycetes, avian antigens, Aspergillus species)
- Gases, fumes, and vapors (chlorine, isocyanates, paraquat, SO2)
- Ionizing radiation
- Talc (injection drug users)
5
Q
Infections associated interstitial lung diseases causes
A
- Fungus, disseminated (Coocidioides immitis, Blastomyces dermatiditis, Histoplasma capsulatum)
- Mycobacteria, disseminated
- Pneumocystic jirovecii
- Viruses
6
Q
Primary pulmonary disorders–interstitial lung dz causes
A
- Cryptogenic organizing pneumonia (COP)
- Idiopathic interstitial pneumonia: Acute IP, DIP, NIP, UOP, RB-ILD, PAP
7
Q
Systemic disorders leading to interstitial lung disease
A
- Acute respiratory distress syndrome
- Amyloidosis
- Ankylosing spondylitis
- Autoimmune Dz: Dermatomyositis, polymyositis, rheumatoid arthritis, systemic sclerosis (scleroderma), SLE
- Chronic eosinophilic pneumonia
- Goodpastures
- Idiopathic pulmonary hemosiderosis
- Inflammatory bowel disease
- Langerhans cell histiocytosis (eosinophilic granuloma)
- Lymphangitic spread of cancer (lymphangitis carcinomatosis)
- Lymphangioleiomyomatosis
- Pulmonary Edema
- Pulmonary venous HTN, chronic
- Sarcoidosis
- Granulomatosis with polyangiitis
8
Q
First step in evaluation of interstitial lung disease
A
- identify patients whose disease is truly idiopathic
- most identifiable causes are infectious, medication-related, or environmental or occupational agents
- dz associated with other medical conditions (pulmonary-renal syndromes, collagen vascular disease) identified through careful medical history
9
Q
All clinical presentations of diffuse interstitial pneumonias are similar to preclude specific diagnosis except Acute interstitial pneumonia. What are diagnostic in some patients?
A
- Chest radiographs and high resolution CT scans
- Ultimately many pts with idiopathic disease require lung biopsy for definitive diagnosis
10
Q
Importance of accurate diagnosis
A
1) allows for providing accurate info about cause and natural history of illness
2) helps distinguish pts most likely to benefit from therapy
11
Q
Clinical presentation of Idiopathic Pulmonary Fibrosis (IPF)– (book says it wrong by calling it UIP–UIP is pattern, IPF is a disease with UIP pattern!!)
A
- 55-60, male
- insiduous dry cough and dyspnea lasting months to yrs
- Clubbing in 25-50%
- Diffuse fine late inspiratory crackles
- Restrictive ventilatory defect and reduced diffusing capacity on PFT
- ANA and RF positive in 25% in absence of collagen dz
12
Q
Histopathophysiology of IPF
A
- Patchy, temporally, geographically nonuniform distribution of fibrosis, honeycomb and normal lung
- Type 1 pneumocytes lost; proliferation of type II cells
- Fibroblastic foci of prolif. fibroblasts and myofibroblasts
- inflammation is MILD–lymphocytes
- intra-alveolar macrophages present but not prominent feature
13
Q
Radiologic pattern of IPF
A
- Diminished lung volume
- Increased linear/ reticular bibasilar, sub pleural opacities
- Unilateral dz is rare!
- CT shows minimal ground glass and variable honeycomb change
- normal lung area may be adjacent to fibroses lung
- possible to have normal chest x-ray and CT (2-10%)
14
Q
Response to therapy and prognosis of IPF
A
- NO improved survival bw untreated and treated
- Progressive!!
- Survival median is 3 years depending on stage at pres.
- Nintedanib and pirfenidone reduce rate of decline in lung fnx
15
Q
Respiratory bronchiolitis associated interstitial lung disease (RB-ILD) clinical presentation
A
- Age 40-45
- Presentation similar to that of UIP though in younger its
- Similar results on PFT but less severe abnormalities
- Heavy smokers!
16
Q
RB-ILD Histopathophysiology
A
- Increased # of macrophages evenly dispersed within alveolar spaces; rare fibroblast foci, little fibrosis, minimal honeycomb change
- macrophage accumulation located in PERIBRONCHIAL AIR SPACES; in DIP, it is DIFFUSE!
- ALveolar architecture preserved
17
Q
Radiographic pattern of RB-ILD
A
- may be indistinguishable from UIP
- nodular or reticulonodular pattern!
- Honeycombing is rare!
- CT shows diffuse ground glass opacities and upper lobe empyema!!
18
Q
RB-ILD–response to therapy and prognosis
A
- Spontaneous remission in 20% so natural Hx unclear
- Smoking cessation essential!!
- Prognosis much better than UIP–median survival more than 10 yrs
- Corticosteroids thought to be effective but no trials to support
19
Q
Acute interstitial pneumonia–clinical presentation
A
- clinically known as Hamman-Rich syndrome
- wide age range, many young
- Acute onset of dyspnea followed by rapid resp failure
- half have viral syndrome preceding
- couse indistinguishable from idiopathic ARDS
20
Q
Histopathophysiology of AIP
A
- acute response to injury within days/weeks
- resembles organizing phase of DAD
- Fibrosis and minimal collagen deposition
- appear similar to UIP but more homogenous and NO honeycomb–but can happen if persists more than 1 month in pt with mechanical ventilation
21
Q
Radiographic pattern of AIP
A
-Diffuse bilateral airspace consolidation with areas of ground glass attenuation on high resolution CT scan
22
Q
AIP response to therapy and prognosis
A
- Supportive care (mechanical ventilation) critical but effect of specific therapies unclear
- high initial mortality–50-50% die within 2months of Dx
- Not progressive if pt survives
- Lung fnx may return to normal or may be permanently imapired
23
Q
Nonspecific interstitial pneumonia clinical presentation
A
- 45-55 yr old female
- Similar to UIP but onset of cough and dyspnea over months, not years
24
Q
NIP Histopathology
A
- nonspecific
- varying inflammation and fibrosis, patchy in distribution but uniform in time suggesting response to single injury
- Most have lymphocytic and plasma cell inflammation without fibrosis
- Honeycombing present but scant
- division into cellular and fibrotic subtypes
25
Radiographic pattern of NIP
- may be indistinguishable from UIP
- most typical picture is bilateral areas of ground glass attenuation on CT
- honeycombing is RARE!
26
NIP response to therapy and prognosis
- Tx thought to be effective but no clinical studies published
- Prognosis overall good but depends on extent of fibrosis at Dx
- Median survival more than 10 yrs
27
Cryptogenic organizing pneumonia (COP; formerly bronchiolitis obliterates organizing pneumonia--BOOP) presentation
Typically 50-60 yrs but variable
- abrupt onset--weeks to few months following flu-like illness
- Dyspnea and dry cough prominent but constitutional symptoms are common--fatigue, fever, weight loss
- PFTs show restriction but 25% show concomitant obstruction
28
COP Histopathology
- included in idiopathic interstitial pneumonias on clinical grounds
- Buds of loose connective tissue (Masson bodies) and inflammatory cells fill alveoli and distal brionchioles
29
Radiographic pattern of COP
- Lung volumes normal
- Chest X ray shows interstitial and parenchymal dz with discrete, peripheral alveolar and ground glass infiltrates
- Nodular opacities common
- CT shows sub pleural consolidation and bronchial wall thickening and dilation
30
COP response to therapy and prognosis
- Rapid response to corticosteroids in 2/3
- Long term prognosis good for those who respond
- Relapses common
31
Symptoms, signs and imaging of diffuse interstitial pneumonias
- most common is pulmonary fibrosis associated with UIP
- when no cause is evident, its called IPF
- Dx of UIP/IPF with 90% confidence in pts>65 when:
1) idiopathic disease by Hx. see inspiratory crackles on PE
2) Restrictive physiology on PFT
3) Radiographic evidence of progressive fibrosis over yrs
4) diffuse, patchy fibrosis with pleural based honeycombing on CT scan
- such patients do not need surgical lung biopsy
32
Special studies used for Diffuse interstitial pneumonias
- Bronchiolar lavage
- Transbronchial biopsy
- surgical lung biopsy, either through open procedure or VATS
33
Bronchiolar lavage
- can provide Dx in cases of infxn esp with P. jirovecii or mycobacteria or when cytologic exam shows malignancy
- can suggest/Dx eosinophilic pneumonia, Langerhans cell histiocytosis or alveolar proteinosis
- Analysis may suggest specific Dz but not diagnostic
34
Transbronchial biopsy
- through bronchoscope
- low risk of pneumothorax and hemorrhage but tissue specimen are small, sampling error common and crush artifact can complicate Dx
- can make definitive Dx of sarcoidosis, lymphangitis spread of carcinoma, PAP, military TB, Langerhans cell histiocytosis
35
Why can the diagnosis of IPF not be confirmed by transbronchial biopsy?
- bc the histologic Dx requires pattern of changes rather than a single pathognomonic finding
- Transbronchial biopsy may exclude IPF by confirming specific alternative diagnosis
- also cannot specifically diagnose idiopathic interstitial pneumonia--requires surgical lung biopsy
36
Surgical lung biopsy
- standard of diagnosis of diffuse interstitial lung dz
- 2-3 biopsies taken from multiple sites in same lung, including normal tissue to yield specific Dx and prognostic info regarding extent of fibrosis and infl.
37
Three reasons to carefully weigh the risks and benefits of surgical lung biopsy in older patients
1) morbidity of procedure can be significant
2) definitive Dx may not be possible even with surgical biopsy
3) when specific Dx is made, there may be no effective Tx
* Empiric tx or no Tx may be preferable to surgical lung biopsy in some
38
Tx of interstitial lung diseases
- RB-ILD, NSIP or COP respond to corticosteroids--give trial of therapies--prednisone 1-2mg/kg/day for 2 mo min
- Above is ineffective for IPF and since above can lead to morbidity, not recommended for IPF
- Antifibrotics (IFN-y 1b) and immunomodulators/suppresors (cyclosporine A, azathioprine, etanercept)--not recommended for IPF!
39
2 agents approved for IPF
nintedanib and pirfenidone--showed significant reduction in rate of decline in lung fnx in trials
- but neither improves survival or quality of life compared with no treatment--$100,000/yr/pt!!!
- only definitive Tx for IPF is lung transplant!!
Respiratory Final
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