Interstitial Lung Disease Flashcards
Definition of idiopathic interstitial pneumonia
Spectrum of pulmonary disorders with characteristic alveolitic change secondary to infilration of immune cells into pulmonary interstitium
Alveolitic pattern of interstitial lung disease characterized by activated macrophages, T-cells, and inflammatory cytokines that activate B-cells to secrete antibodies
Idiopathic interstitial pneumonia
MOA of idiopatich interstitial pneumonia
antibody/antigen complex deposition in lung parenchyma > activation of complement system > inflammatory reaction with parenchymal tissue injury
further destruction by neutrophils, macrophages (TNF, IL-1), prostaglandins, and cytokines
ultimatley, inflammation and injury may result in irreversible fibrosis
Sx of idiopathic interstitial pneumonia
progressive dyspnea and non-productive cough (over months - years)
Diagnostic w/u for idiopathic interstitial pneumonia
H&P
ABG
PFTs
Labs
Bronchoscopy
High-resolution CT
Biopsy (usually surgical, occasional transbronchial)
Success of transbronchial biopsy for diagnosis in idiopathic interstitial pneumonia
25%
Treatment plan for idiopathic interstitial pneumonia
- Oxygen supplementation
- Removal of causitive agents
- Early intervention to prevent progression of fibrosis
Cornerstone of therapy for interstitial lung disease
Steroids
- 20% of IPF patients will respond to steroids
- Alternative therapies include:
- cyclophosphamide
- azathioprine
- methotrexate
- penicillamine
- cochicine
- cyclosporine
- INF-gamma
Treatment of interstitial lung disease after failure of medical managment
Lung transplantation
SOC for intersitial lung disease (IPF)
Single lung transplant
Criteria for transplant
- Progressive dyspnea/hypoxia despite maximal medical therapy
- VC <= 60 - 70% predicted
- DLCO <= 50 - 60% predicted
- Age < 60 yrs (double lung transplant) or <65 yrs (single lung transplant)
5- year survival after transplant for IPF
]50-60%
(28-month median survival for IPF with medical treatment alone)
Defined by thickened, fibrotic alveolar interstitium with lymphocytic and plasmacytic infiltration
Usual interstial pneumonia (UIP) / Idiopathic pulmonary fibrosis (IPF)
UIP / IPF demographics
males
age > 50
Etiologies of UIP / IPF
Etiology largely unknown
- Infectious
- hepatitis C
- EBV
- Environmental
- heavy metal dusts
- solvents
- cigarette smoking
- Genetic
- HLA-B15, B8, B12
- Immunologic
- Rheumatoid arthritis
- SLE
- Systemic sclerosis
Most common CT findings with UIP / IPF
- Mediastinal lymphadenopathy
- Lower lobe/subpleural predominance
- Reticurlar or reticulnodular pattern
- Honeycombing cysts
- Ground glass opacities
Diagnosis and Treatmetn of UIP/IPF
- Diagnosis:
- surgical biopsy
- Treatment:
- High dose steroids
- Transplant
Favorable prognostic factors for UIP / IPF
- young age
- disease < 1 year
- active inflammation
- lymphocytosis on BAL
- presence of immune complexes
5 - year survival for UIP / IPF
- Responders (43%)
- Non-responders (20%)
ILD subtype characterized by mildly thickened intersitium, spare infiltration of inlfammatory cells, mild fibrosis and filling of alveoli with macrophages
Desquamative interstitial pneumonia (DIP)
MC affected patient population with DIP
Smokers aged 40-50 years old
Characteristic imaging appearance of DIP
Bilateral ground glass opacities in a linear pattern
TOC for DIP
Steroids (more amenable to therapy than UIP/IPF)
May progress and require lung transplantation
ILD subtype characterized by mildly thickened interstitium, infiltration of inflammatory cells, and mild fibrosis in patchy distribution with uniform histology
Nonspecific interstitial pneumonia (NIP)
Compared to UIP/IPF, NIP has (improved or worse) response rate to steroid therapy and (better or worse) overal survival?
Improved response rate
Better overall survival
ILD subtype characterized by chronic inflammation of alveoli, granulation tissue in bronchioles/alveoli, and accumulation of macrophages within alveoli with patchy distribution and uniform histology
Brochiolitis obliterans organizing pneumonia (BOOP) / cryptogenic organizing pneumonia (COP)
MC affected population with BOOP/COP
Men and Women equally
Age 40-60 years
Imaging appearance/characteristics of BOOP/COP
Airspace disease with bilateral diffuse ground-glass opacities
TOC for BOOP/COP
Steroids (rapid resolution of disease process typical)
Surgical role: biopsy for diagnosis
Outcomes for BOOP/COP
Mortality ~ 12%
Relapses after steroid therapy common (respond favorably to addnl steroid rx)
ILD subtype characterised by infilration of lymphocytes and plasma cells in lung parenchyma without alveolar damage
Lymphocytic insterstial pneumonia (LIP)
Often associated with:
- Immune disorders:
- Sjogren’s syndrome
- SLE
- Myasthenia gravis
- Chronic active hepatitis
MC affected patient populations with LIP
Children (50% of HIV+ children with pulmonary disease)
Immunocompromised
Women (40-80 yo)
Imaging appearance/characteristics of LIP
Reticular/reticulonodular pattern and airspace consolidation
TOC and Outcomes for LIP
Treatment: steroids (surgery for diagnostic bx)
33-50% mortality within 5 years of diagnosis
5% progress to lymphoma
Chronic systemic disorder of unknown etiology characterized by noncaseating granulomas within multiple organ systems
Sarcoidosis
MC affected patient population with sarcoidosis
Females
African ancestery
Age: 20-40 years
Causal theories for sarcoidosis
- Enviornmental
- Workplace clusters
- Infectious
- lymphadenopathy
- M. tuberculosis
- Hereditary
- HLA-A1 and -B1
- Immunologic
- altered T cell ratios
- impaired systemic immunity
- hyperactive B-cell lines
- altered macrophage productin of INF-G and RANTES
Sarcoidosis involves lungs in _% of cases
~ 94%
MC extrapleural sites invovled in sarcoidosis
- Eyes
- uveitis
- conjunctivitis
- retinitis
- Skin
- nodules
- plaques
Sarcoidosis occasionally associated with what other conditions
- Rheumatoid arthritis
- SLE
- Progressive systemic sclerosis
- Lofgren’s syndrome
Imaging appearance/characteristics of sarcoidosis
Lymphadenopathy
Upper lobe predominance
Variable interstitial/aciner lesions
Occasional nodules
Serum and/or BAL fluid marker elevated in sarcoidosis
ACE (angiotensin coverting enzyme)
Clinical presentation of sarcoidosis
Asymptomatic (30-50%)
- Hilar or mediastinal adenopathy (80%)
- Constitutional symptoms (fever, chills, malaise, weight loss)
- Elevated ACE levels (serum and BAL fluid)
- Restrictive lung function (occasionally obstructive)
- Hypercalcemia
- Peripheral lymphopenia
Radiographic staging of sarcoidosis
- Stage 0 (8%): normal
- Stage I (50%): lymphadenopathy
- Stage II (30%): lymphadenopathy and parenchymal infiltrates
- Stage III (12%): parenchymal infiltrates only
- Stage IV (rare): end-stage honey-comb lung
Dx workup for sarcoidosis
- PFTs
- Diagnostic bronchoscopy (BAL and transbronchial bx)
- High resoluation CT scan
- Medistinoscopy or VATS bx (non-caseating granulomas, elevated tissue ACE)
Natural history of pulmonary sarcoidosis
Most remain stable
20% suffer progressive pulmonary deterioration
TOC for sarcoidosis
Steroids
Alternative rx: metotrexate, cyclosporine, chlorambucil
Therapeutic recommendatons for sarcoidosis
High remission rate:
Asymptomatic stage I or II with normal PFTS (expectant managment)
Symptomatic stage II or any stage III (treatment)
Extrapulmonary manifestations (treatment)
Mortatliy rate for sarcoidosis
4%
(most deaths attributable to pulmonary disease)
