SM 163 Introduction to DPLD Flashcards
What is DPLD and what is it’s other common name?
Diffuse Parenchymal Lung Disease aka Interstitial Lung Disease (ILD) = a group of diverse disorders
What part of the lung does DPLD effect?
DPLD effects the Alveolar wall, especially the interstitium, alveolar space, and small airways
Does DPLD effect large or small airways?
Small airways - also alveolar spaces
What type of cell are Type II Pneumocytes?
Cuboidal
What type of cell are Type I Pneumocytes?
Squamous
What is the most essential part of diagnosis of DLPD?
A careful history
What should the history in DLPD consider?
Focus the history on potential inhaled exposures, such as occupation, hobbies, pets, drugs, smoking/vaping
What diseases are associated with DLPD?
IPF (a form of UIP) and Sarcoidosis
What diseases are not associated with DLPD?
Hypersensitivity Pneumonitis and Rheumatoid Arthritis
Which lung cell types are most susceptible to injury?
Type I Pneumocytes
How does DLPD present in terms of symptoms?
Symptoms = slow-onset exertional dyspnea, non-productive cough
What physical findings suggest DLPD?
Fine crackles, digital clubbing, cyanosis, right heart failure
Can DLPD involve systemic illness?
Yes, things like Rheumatoid Arthritis can cause IPF
How can DLPD present on CXR?
May be normal 10% of the time, but also shows interstitial and alveolar patterns
What is the interstitial pattern of ILD?
Reticular and nodular findings on CXR at the base of the lung
What is the alveolar pattern of ILD?
Diffuse and patchy in the upper lung
What is HCRT?
High resolution computed tomagraphy
How does HCRT differ from CT?
More sensitive, can be diagnostic, can guide surgery
What HCRT finding is associated with Scleroderma?
Reticular opacities
What HCRT finding is associated with Sarcoidosis?
“Tree-in-Bud” opacities
What HCRT finding is associated with Hypersensitivity Pneumonitis?
Ground Glass opacities
What can reticular opacities suggest?
Scleroderma
What can “tree-in-bud” opacities suggest?
Sarcoidosis
What can Ground Glass Opacities suggest?
Hypersensitivity Pnumonitis
What is Traction Bronchiectasis?
The airways being ope ned pathologically due to continued inflammation
What can spirometry measure?
Minute ventilation
What can spirometry tell us?
Low FEFV1/FCR = obstructive lung disease
What does restrictive tell us?
High or Normal FEV1/FCR = restrictive lung disease
Is DLPD a restrictive or obstructive?
Restrictive, though mixed restrictive/obstructive is also possible
How does DLPD show up on spirometry?
Decreased lung volumes, normal/increased FEV1/FVC
How does DLPD show up on the pressure-volume curve?
Decreased compliance = flatter slope
How does DLPD effect DLCO?
Reduced DLCO
How does DLPD effect exercise testing?
Subjects will be abnormal earlier than unaffected patients, with increased A-a gradient, decreased PaO2, and increased Vd/Vt
How do DLPD get categorized?
DLPD: known vs unknown cause
DLPD known: exposure vs systemic disease
DLPD known exposure: occupational vs treatment
DLPD known systemic: granulomatous vs connective tissue disease
What are occupational variants of DLPD?
Occupational variants of DLPD include Asbestosis and Silicosis, which occur due to exposure to an inhaled antigen
What are treatment variants of DLPD?
Treatment variants of DLPD result from Radiation and Amiodarone, which occur due to exposure to the treatment for another disease as a side effect
What are systemic variants of DLDP?
Systemic variants of DLPD result from Rheumatoid Arthritis and Scleroderma, which effect connective tissue through the entire body, including the Lungs
What is the primary DLPD of unknown cause?
Idiopathic Interstitial Pneumonias, including IPF
What is an IIP?
A class of DLPD, all of unknown cause
What are the major IIP’s?
Idiopathic Pulmonary Fibrosis (IPF)
Idiopathic Nonspecific Interstitial Pneumonia (NSIP)
Acute Interstitial Pneumonia (AIP)
Cryptogenic Organizing Pneumonia (COP)
What are the rare IIP’s?
Idiopathic Lymphocytic Interstitial Pneumonia (LIP)
Idiopathic Pleuroparenchymal Fibroelastosis
What is the newest IIP?
IPAF, the autoimmune version
What is the most common IIP?
IPF
What types of DPLD can have both known and unknown causes?
Granulomatous lung disease, such as Sarcoidosis and Hypersensitivity Pneumonia
What are potential infectious causes of DPLD?
TB, non-TB mycobacteria, Histo/blasto/coccidio fungal
What are the potential non-infectious causes of DPLD?
Sarcoidosis, Beryliosis, and Hypersensitivity Pneumonitis
What causes Berrylliosis?
Exposure to Berrylium, a metal, due to an occupation
What are the immune effects of Sarcoidosis?
Increased Th1/Th17 responses at the site of disease
What type of drug does Sarcoidosis respond to?
Steroids
What needs to be excluded to diagnose Sarcoidosis and how?
Need to exclude infection with culture and stain, as well as excluding potential immune response
What organ is mainly affected by Sarcoidosis?
The Lung, skin and eyes common too
How does Sarcoidosis present on CXR?
Sarcoidosis results in nodes in the mid and upper lungs, which represent well organized granules
What is a giant cell?
Fused macrophages, commonly found in granulomas
What is Hypersensitivity Pneumonitis?
An immune-mediated lung disease that can be triggered by inhaled organic antigens
Do innate or adaptive immune response mediate Hypersensitivity Pneumonitis?
Both Innate and adaptive immune responses play a role
What type of antibody is involved in Hypersensitivity Pneumonitis?
IgG targeted towards the offending antigen
Does Hypersensitivity Pneumonitis present acutely, subacutely, or chronically?
All of the above
How does Hypersensitivty Pneumonitis present acutely?
Fever/chills/dyspnea within 4-8hrs of exposure
How does Hypersensitivity Pneumonitis present subacutely?
Gradually over weeks
How does Hypersensitivity Pneumonitis present chronically?
Insidious onset of dyspnea, cough, hypoxemia over months-years
What is the most essential part of diagnosis for Hypersensitivity Pneumonitis?
Detailed exposure history
What does Hypersensitivity Pneumonitis look like on HRCT?
Ground glass opacities if acute/subacute, traction bronchiectasis if chronic
What tests can be used to diagnose Hypersensitivit Pneumonitis?
PFT’s, serum antibodies, BAL, lung biopsy
What factors are essential for diagnosis DPLD?
History, serology, and HRCT pattern
Why is bronchoscopic biopsy limited in DPLD?
Biopsy samples are too small for most diagnoses, except cancer, sarcoid, and infection
What is the gold standard for lung biopsy?
Surgical lung biopsy
How are pneumoconiosis treated?
Terminate the expousre
How is IPF treated?
DO NOT USE CORTICOSTEROIDS
Pirfenidone and Nintedinib
How are NSIP and IPAF treated?
TRAC = Tacrolimus, Rituximab, Azathioprine, Corticosteroids
How does Rituximab work?
mAb against CD-20 on B-cells
How is Sarcoidosis treated?
CAT = Corticosteroids, Azathioprine, TNF inhibitors
What are infliximab and adalimumab?
TNF inhibitors
How is Hypersensitivity Pneumonitis treated?
Termination of exposure if offending antigen is identified
Corticosteroids
What is the interstitium?
A potential space between the alveolar epithelium and capillary endothelium
What are the common symptoms of DLPD?
Dyspnea, cough, fatigue, and weight loss as the disease progresses
What symptom is most specific to IPF?
Digital clubbing
What disease is associated hilar and mediastinal lymphadenopathy?
Sarcoidosis
Does the presence of antibodies indicate DLPD?
Not necessarily
How do DLPD effect diffusion capacity?
Decreased diffusion capacity as seen on lower DLCO
