EXAM #1: PATHOLOGY OF ILD Flashcards
What external pathologies can cause restrictive lung disease?
1) Deformed chest wall i.e. scoliosis or obesity
2) Pleural space filled
What is the defining feature of the Interstitial Lung Diseases (ILDs)?
Inflammation and fibrosis of pulmonary connective tissue/ peripheral interstitium between alveolar walls
What are the PFT findings in the ILDs?
1) Decreased TLC
2) Decreased FEV1
3) Dramatically decreased FVC
*Normal to increased FEV1/FVC ratio
How do the ILDs present?
1) Dyspnea
2) Hypoxia
3) End-inspiratory crackles
What is the pathognomonic description for the end-stage of the ILDs?
“Honeycomb lung”
Where is the pathologic disturbance occurring in ALI or ARDS?
Inflammatory damage at the alveolar-capillary interface
*Consequently, this is called non-cardiogenic pulmonary edema or DaNang Lung
What is the clinical features of ALI or ARDS?
- Rapid onset dyspnea
- Refractory to oxygen therapy
What causes ALI or ARDS?
1) Sepsis
2) Infection
3) Shock
4) Trauma
5) Aspiration
6) Pancreatitis
7) DIC
8) Hypersensitivity
9) Drugs
10) Transfusion i.e. “TRALI”
What PaO2/FiO2 ratios define ALI and ARDS?
ALI= less than 300 ARDS= less than 200
What causes the damage seen in ARDS?
Neutrophil secreted proteases
What is the cause of neonatal ARDS?
Lack of surfactant
How is ARDS treated?
1) Address the underlying cause
2) NO to reduce resistance in pulmonary artery
3) PEEP
What are the complications of ARDS in those that survive?
Scarring and fibrosis leading to chronic ILD
What are the phases of ARDS recovery?
1) Exudative stage with hyaline membranes
2) Fibrotic stage
What is TRALI? What causes TRALI?
- Transfusion-related ALI
- Caused by anti-HLA or anti-HNA antibodies
What is the treatment for TRALI?
Immediately stop tranfusion
Generally, what is the progression seen in diffuse interstitial disease?
1) Alveolitis
2) Leukocytes accumulate
3) End-stage fibrotic lung i.e. honeycomb lung
What cell plays a key role in mediating the pathology seen in diffuse interstitial disease?
M2 macrophage
What is the histological pattern associated with Idiopathic Pulmonary Fibrosis (IPF)?
UIP– “usual interstitial pneumonia”
What is the definitive treatment for IPF?
Lung transplant
What is the current theory of IPF pathogenesis?
“Repeated cycles” of epithelial activation/injury with an OVERWHELMING healing response
What cytokine is implicated in the overwhelming healing response seen in IPF?
TGF-B1
What is “temporal heterogeneity” referring to in IPF?
- Cyclic healing causes collagen deposition
- B/c it is cyclic, different stages of collagen will be present
Thus, temporal heterogeneity is referring to different stages of collagen deposition.
What is essential to remember about IPF or seeing a UIP pattern in regards to treatment?
This requires lung transplant
*Other ILDs are responsive to steroids
What collagen vascular disorders are associated with ILD?
1) RA
2) Scleroderma
3) SLE
What is a pnemoconiosis?
Interstitial fibrosis caused by an occupational exposure
What is a key factor in pneumoconiosis?
Capacity of the inhaled particle to stimulate alveolar macrophages that initiate inflammation and fibrosis
What is Coal Worker’s Pneumonconiosis (CWP)?
Pneumoconiosis caused by inhalation of carbon dust
What are the three degrees of CWP?
1) Asymptomatic anthracosis= no sx.
2) Simple CWP= minimal dysfunction
3) Complicated CWP= severe degree of dysfunction
Is CWP associated with an increased risk for cancer or TB?
NO
What is PMF?
Pulmonary Massive Fibrosis
- severe fibrosing reaction that can complication ANY pneumoconiosis
- massive amounts of carbon dust= major culprit
What is Caplan Syndrome?
CWP + RA
What is Silicosis?
Pneumoniosis associated with scilica i.e. sandblasting, masonry, and fine stone particles
What particle is most fibrogenic and thus most dangerous in terms of Scilicosis progression?
Quartz
What is unique about the risk profile associated with Scilicosis?
This is the ONLY pneumoconiosis that increases the risk of cancer AND TB
*Scilica impairs the formation of the phagolysosome, which is what increases the risk for TB
Histologically, what is pathognomonic for Scilicosis?
“Whorls of collagen” in the fibrosis seen with Scilicosis
What test is a good test to confirm Scilicosis?
Polarized light–the rock particles will light up
What are the two types of particles seen in Asbestosis?
Serpentines= more common, less pathogenic Amphiboles= less common, more pathogenic
What types of occupations were historically most exposed to Asbestos?
1) Construction workers
2) Plumbers
3) Shipyard workers
What type of cancers are associated with asbestos exposure?
1) Lung carcinoma
2) Mesothelioma
Mesothelioma occurs later than the more generic lung carcinomas; thus, lung carcinoma is MORE COMMON
What is an asbestos body?
Dumbbell shaped golden-brown fibers coated with iron
Describe the pathogenesis of the pleural plaques seen in asbestosis.
Larger asbestos fibers penetrate the alveolar sacs and pleura, forming fibrotic plaques in the pleura
How much does asbestos increase the risk of lung carcinoma? How if the individual smokes in addition to the exposure?
- 5x increase if just asbestos
- 55x increase if patient smokes too
List the drugs that classically cause drug-induced pulmonary disease. What conditions are caused by these drugs?
1) Bleomycin= pneumonitis and fibrosis
2) Methotrexate= hypersensitivity pneumonitis
3) Amiodarone= pneumonitis and fibrosis
4) Nitrofurantoin= hypersensitivity pneumonitis
5) Aspirin= bronchospasm
6) Beta-antagonists= bronchospasm
What are the two types of radiation induced lung disease?
- Acute= occurs 1-6 months post treatment
- Chronic= failure of acute disease to resolve, causing pneumonitis and pulmonary fibrosis
What medication is indicated for the treatment of radiation-induced lung disease?
Steroids
What is the mesothelioma?
Cancer of the pleura associated with asbestos exposure
What is Berylliosis?
Pneumoconiosis caused by exposure to Beryllium
What types of workers are exposed to Beryllium?
Miners and aerospace workers
What does Berylliosis cause?
Non-caseating granulomas of the lung, hilar lymph nodes, and systemic organs
*Note that this strongly resembles SARCOIDOSIS
What disease do you want to be sure not to confuse Berylliosis with?
Sarcoidosis
