lec 6+7 restrictive lung disease Flashcards
Restrictive pulmoanry diseases:
-predominantly diffuse
-acute- ARDS
-Chronic involves fibrosis of pulmonary connective tissue
pulmonary function tests compared to obstructive:
-FEV1 slightly decreased
-FVC significantly decreased
FEV1/FVC close to normal or sometimes increased
3 Characteristics of restrictive disease:
-inspiratory dyspnea
-X ray: bilateral diffuse pulmonary infiltrates
-resp failure, pulmonary hypertension, honeycomb lung
Pathogenisis of restrictive lung disease:
-injury of type 1 epithelium—-alveolitis
-Macrophage activation —- fibrogenic cytokines recruitment, inducing fibrosis.
Later stage of ARDS:
-Macrophage derived fibrogenic factors
-fibroblast recruitment—- fibrosis
These can be counteracted by antiproteases,antioxidants,anti-inflammatory cytokines.
clotting cascade is also activated
Fibrosing reaction: 1)idiopathic pulmonary fibrosis
-M>F, older than 60
-diagnosis of exclusion
-severe hypoxemia and cyanosis
-histological pattern of usual interstital pneumonia UIP
Clinical features of IPF:
-Insidious presentation
-Non productive cough and severe dyspnea
Examination of IPF:
-Cyanosis, clubbing, dry crackle inspirations
- Chest x-ray: bilateral basal nodular infiltrates then progresses to whole lung later
-Lung biopsy+* bronchoalveolar lavage* (applying fluid into trachea then collecting it)
prognosis: death in 2-4 years
Morphology of IPF:
-cobblestone surface
-interstitial chronic inflammation
-Temporal heterogeneity temporal=time Heterogen= diverse
-basal, along pleura and septa
- patchy fibrosis, irregular cystic fibrosis lined by hyperplastic type 2 pneumocytes or bronchiolar lining (honeycomb lung)
2)non specific interstitial pneumonia:
-Abscence of temporal heterogeneity.
-wastebasket diagnosis, of ANY pneumonia
-mature fibrosing pattern
-cellular pattern: infiltrate
3)cryptogenic organizing pneumonia:
-no temporal heterogeneity, interstital inflammation
-polypoid plugs fibrosis in bronchioles and alveolar ducts and alveoli
-no destruction of lung architecture
-recovery within 6 months with steroids
4)collagen vascular disease
rheumatoid arthritis
SLE
scleroderma
any interstitial pattern
can trigger systemic inflammation in lung, causing lung fibrosis
5)pneumoconiosis/environmental diseases
-non neoplastic lung reaction exposure to coal , silica, asbestos dusts
- Particles 1-5 micrometers in diameter, most dangerous. because they get loaded at distal airways .
- tobacco smoke worsens it.
Types of pneumoconiosis: Anthracosis (coal miners lung)
-seen in tobacco smokers
-inhaled carbon pigment
-No increase in risk of lung cancer
1)simple coal worker pneumoconiosis
coal macule: consist of dust laden-macrophages
Coal nodule: larger and contains collagen
upper lobe more involved than lower lobe: centrilobular emphysema might occur
2)complicated CWP
we have multiple nodules, then they coalesce, forming a large nodule (2-10cm)
3)progressive massive fibrosis:
pulmonary dysfunction
pulmonary hypertension
Cor pulmonale
B-sillicosis:
inhaling crystalline silica: quartz.
acute heavy exposure— ARDS
chronic after 20-40yrs exposure
pathogenisis of sillicosis:
-sillica in macrophages — injury to cell membrane
- starts as small nodules, then enlarges to 1-10cm
- polarized microscopy shows weakly befringent silica particles
-X ray shows: egg shell calcification
-honeycomb
Clinical picture of sillicosis:
-asymptomatic
-inc chance of lung cancer and TB
C) asbestos induced lesions
-2 types: Serpintene and amphibole
-Lesions include:
1)asbestosis, lower lobe–honeycomb lung and cor pulmonale
2)pleural effusion and fibrosis
3)pleural plaques:most common
4)malignant mesothelioma
5)**inc risk of lung CA and larynx **
from cancer chemotherapy(bleomycine)
-anti arrythmic patients (amiodarone)
1) Sarcoidosis
multisystem disorder
age younger than 40
etiology:
genetic predisposition (HLA-A1) and (HLA-B8).
immune mechanisms of Sarcoidosis:
-Type IV hypersensitivity reaction
-T lymphocyte abnormalities:
- oligoclonal expansion of T cell subsets
- decreased CD4/CD8
- alveolar lavage: inc T cells
- Inc level of IL-8, TNF, MIP-1a locally
- polyclonal hypergammablobulinemia
pathology of Sarcoidosis:
-non caseating granulomas eith giant cells containing schaumann and asteroid bodies.
-Occular involvment = SICCA syndrome
-Parotid involvment= MIKULICZ syndrome
Clinical picture and radiograph of sarcoidosis:
diagnosis
fever, dyspnea
chest radiograph shows;
bilateral hilar lymphadenopathy
ground glass miliary shadows in both lungs
hypercalcemia
diagnosed by exclusion of all other granulomatous conditions
Skin test: KVEIM test
hypersensitivity pneumonitis:
-type III and type IV reactions
-immunologically affects airways and interstitium
- can be farmers lung , pigeon breeder, air condition lung
the way hyeprsensitivity pneumonitis is presented in questions:
-pigeon breeder /farmer lung
-asthma attack, dyspnea, fever
-morphology: poorly formed epitheliod granulomas (non caseating)
