Categories of Chronic Interstitial Lung Disease
- Fibrosing (usual/idiopathic pulmonary fibrosis or pneumoconiosis)
- Granulomatous (Sarcoidosis)
- Eosinophilic
- Smoking related
Interstitial Lung Disease clinical presentation
- dyspnea
- end inspiratory crackles
- hypoxia
Interstitial Lung Disease Lab
Chest radiographs
-Nodules, irregular lines, ground glass shadows
Complications of Interstitial Lung Disease
- Resp. failure via pulmonary HTN or cor pulmonale
- Honeycomb lung (end stage pathology)
Cause of Usual/Idiopathic Pulmonary Fibrosis
-repeated cycles of lung injury and wound healing with increased collagen
Pathology of Idiopathic Pulmonary Fibrosis
-Pleural surface scarring (cobblestoned)
-firm, rubbery white cut surface
-patchy interstitial fibrosis
Early: exuberant fibroblastic proliferation
Clinical Presentation of Idiopathic Pulmonary Fibrosis
- 40 to 70 years old more in men
- Dyspnea on exertion (DOE)
- Dry cough
- Velcro crackles
- Deterioration, less than 3 year survival
- Lung transplant only definite Tx
What is pneumoconiosis?
The accumulation of dust in the lungs and the tissue reaction to its presence
What pneumoconiosis is coal dust?
Anthracosis from coal mining
-Caplan syndrome suggesting rheumatoid arthritis modifies response to coal mine exposure
What pneumoconiosis is silica?
Silicosis from sandblasting
- most prevalent chronic world occupation disease
- Nodules: concentric hyalinized, whorled appearance
- inc. susceptibility to TB
What pneumoconiosis is asbestos?
Asbestosis from ship building, roofing, or plumbing
- Asbestos bodies and/or pleural plaques
- 5x increase chance for lung cancer (55x if they smoke too)
- malignant mesothelioma is 1000x w/ asbestos but not cig smoke with latency of 25-40 years
What pneumoconiosis is beryllium?
Berylliosis from mining, fabrication, or stealth jet building
What is the pathogenesis of pneumoconiosis?
- inhaled dust largely entrapped in mucus
- 1 to 5 micrometer particles are most dangerous
- They reach the terminal small airways, air sacs, and settle in lining
- Macrophages endocytose trapped particles and release inflammatory mediators which lead to fibrogenesis and collagen deposition
Classification of Sarcoidosis
multi system disease of unknown etiology
- characterized by non-caseating granulomas
- diagnosis of exclusion
Sarcoidosis CXR
Abnormalities in 90% of patients
- Bilateral hilar lymphadenopathy
- Lung parenchymal abnormalities
Sarcoidosis pathogenesis
- CD4 T cells dominant in sarcoid granulomas
- Tregs down regulated
- INF gamma activates macrophages
- TNF is a mediator of granuloma formation
Clinical Presentation of Sarcoidosis
- usually young adults
- African americans, danish, swedish
- usually upper lobe
- SOB, dry cough, non-specific
- 10 - 15% progress to pulmonary fibrosis
- 2/3 of patients are asymptomatic
Histology for Sarcoidosis
- Non-caseating granulomas
- coalesce granulomas with a rim of lymphocytes, embedded in eosinophilic collagenous storm
- present along lymphatic routes
- multinucleated giant cells with cytoplasmic inclusions: Schumann bodies, steroid bodies
Dx of Sarcoidosis
transbronchial biopsy in 90% if 4 pieces submitted
- routine AFB and GMS
- Dx of exclusion
Labs for Sarcoidosis
- elevated ACE level
- hypercalcemia
- markers to systemic immune abnormalities (anergy to common skin test antigens)
- Polyclonal hypergammaglobulinemia
