Interstitial lung disease (ILD) encompasses over 250 different diseases affecting the lung interstitium, characterized by inflammation and fibrosis. The document discusses the causes, classifications, diagnosis, and treatment of ILD, highlighting idiopathic pulmonary fibrosis as a prevalent form with a poor prognosis. Diagnostic approaches include clinical features, imaging, pulmonary function tests, and biopsy, while treatments aim to alleviate symptoms, slow progression, and improve quality of life.

1. INTERSTITIAL LUNG
DISEASE

2. Interstitial Lung Disease
Diseases of lung interstitium
Not a single disease – over 250 different diseases with similar clinical
and/or radiological features
Also known as : Diffuse Parenchymal Lung Disease or Diffuse Lung
disease because of Involvement of air spaces , vessels, airways, ?pleura -
i.e. diffuse involvement
Idiopathic pulmonary fibrosis (IPF) or Idiopathic Interstitial
Pneumonias (IIPs) are sometimes used synonymously with ILD

4. Characteristics
 Common clinical, radiological, physiological and histo pathologic
features
 Hetero genous conditions
- Inflammatory
- Granulomatous
- Infections
- Depositions
- Oedema

5. Causes and Pathogenesis
 Exact etiology, not know – Idiopathic
 Secondary to other known causes
 Inflammation, damage and fibrosis
 Repair mechanisms (for inflammation) - aberrant
 Diffuse involvement
 Progressive

6. AETIOLOGICAL CLASSIFICATION
1. Occupational and environmental exposures
2. Connective tissue diseases
3. Drugs and Poisons
4. Infections (residual scars)
5. Miscellaneous systemic dis
6. IDIOPATHIC (or PRIMARY)

7. Primary ILDs - IIPs
UIP: Usual Interstitial Pneumonia or IPF
AIP: Acute Interstitial Pneumonia
DIP: Desquamative Interstitial Pneumonia
NSIP: Non-specific Interstitial Pneumonia
LIP: Lipoid Interstitial Pneumonia
OP: Organizing pneumonias

8. Secondary I.L.Ds
Acquired /Systemic Inhertied
 CTDs • Familial
 Granulomatoses • Tuberous sclerosis
 Pneumoconiosis • Neurofibromatosis
 Infections • Metabolic storage disease
 R.B-I.L.D • H-P syndrome
 Hypersenstivity Miscellaneous
 Pneumonias • Idio. pulm. haemosiderosis
Iatrogenic • Veno-occlusive disease
 Drugs, Radiations • L.A.M.
 Toxic gases,fumes • Histiocytosis

9. Connective Tissue Disorders
PSS Skin and digital changes
Rh arth Polyarticular arthritis
SLE Multisystem disease
PM-DM Skin and muscle
Sjogren Dryness in eyes, mouth, glands
Ank Spond Seroneg. Spondylo-arthritis
Mixed CTD SLE, SSC and PM-DM
Relapsing PC Polychondritis (nose, ear)
Behcet Dis. Aphthous ulcers; genital

10. Iatrogenic ILD
1. Drugs
Cytotoxic: Bleomycin, mitoC, busulfan, BCNU
Noncytotoxic: • Aspirin
• Antibiotics – NFT, sulfasalazine
• Anti arrythmics: Amiodasone, BB
• Anti-inflammatory: NSAIDs, gold
• Anticonvulsants: Dilantin, CM
• Vasodilators: Hydralazine
• Narcotics: Opiates, heroin
• Miscellaneous: Penicillamine,
vitamins
2. Therapeutic radiation
3. Oxygen toxicity

11. Drugs and Chemicals
1. Chemotherapeutic agents
Busulphan, Metho, Bleo
2. Antibiotics
3. Misc. drugs: Dilantin, Gold,
Procainamide, Aminodarone
4. Fumes of Zn, Cu, Mn, Cd, Fe,
Mg, Ni, Se, brass
5. Aerosols: Fats
6. Vapours: Resins, TDI, Hg
7. Paraquat

12. SYSTEMIC DISEASES
1. Sarcoidosis
2. Vasculitides
Wegener’s GM
Churg Strauss Syn
3. Good Pasture’s syn
4. Idiopathic haemosiderosis
5. Histiocytosis X
6. Lymphangitis carcinomatosis
7. Ch. Pulm oedema / uraemia
8. Alveolar proteinois

13. Honey Comb Lung
 Irreversible end-stage disease
 Cystic space formation
Dense fibrosis
Metaplastic cuboidal epithelium
Mucus formation
 Interstitial smooth m. proliferation
 Pulmonary vascular change
 Malignant change (potential)

14. DIAGNOSIS
 Clinical features
 Laboratory investigations: Hematological, biochemical,
immunological etc.
 Radiology: CXR, HRCT
 Pulmonary function tests
 Bronchoscopy: BAL, lung biopsy
 Surgical lung biopsy

15. Diagnosis Issues
1. Diffuse vs. Local
2. Primary vs. Secondary
3. Cause of secondary ILD
4. Acute vs Chronic
5. Disease activity and progression
6. Responsive vs Nonresponsive
(to tmt)
7. Presence of complications

16. DIFF. DIAGNOSIS
1. Causes of breathlessness
. Left heart failure
. Pulm. Thromboembolism
. Miscellaneous-anemia
2. Respiratory Diseases
. COPD
. Bronchiectasis
. Ch. Pneumonias- eosinophilic

17. SYMPTOMS
 Progressive breathlessness
 Cough (non productive)
 Onset: Insidious / acute
 Symptoms / history of underlying disease/exposure

18. PHYSICAL EXAMINATION
 Tachypnoea
 Reduced chest expansion / intercostal retraction
 Exercise induced cyanosis
 Clubbing
 Breath sounds – well heard
 Bibasilar end-inspiratory day (Velcro) crackles
 Pulm hypert / cor pulmonale
 Signs of CTD or other causes responsible for ILD

19. INVESTIGATIONS
1. Haematological – leucocytosis, Polycythaemia / anaemia
2. Biochem: (renal, Liver)
3. Raised ESR, hypergammaglob.
4. Immunological tests: LE cell, Rhematoid factor,
Antinuclear Ab., Immune complexes
5. Cardiac function
6. Others: ACE, LDH, antibodies (etc.)

20. RADIOLOGICAL STUDIES
1. What is most helpful?
Diagnosis
Disease extent
Progression
2. Radiological findings: distribution and pattern
3. Correlation
4. Cost-effectiveness

21. CLASSICAL RADIOGRAPH
 Basilar / diffuse shadows
reticular/nodular/RN
 Mixed patterns ?
 Honey combing
 Decreased volume
 Pulm hypertension

22. ATYPICAL PATTERNS
1. Upper zone predominance: Granulomatous dis.,
Pneumoconioses
2. Increased volume: LAM, Sarcoidosis
3. Pleural involvement: CTD, sarcoidosis, Asbestosis, Drugs
4. Miliary pattern : TBL, Granulomatoses

23. 5. Hilar / mediastinal LN
Sarcoidosis
Lymphoma / Lymphangitis
6. Pneumothorax
Histocytosis X / LAM
7. Kerley B lines
8. Normal CXR

24. HIGH RESOLUTION CT
 Better resolution / more accuracy
 Earlier detection
 Better assessment of extent and distribution
 Occult adenopathy
 Selection of biopsy site

25. PULM. FUNCTION TEST
1. Restrictive pattern
Reduced TLC, VC
FRC and RV
2. Flow rates: Reduced due to decreased VC
. Obstructive/mixed pattern :
smoking/other causes
3. Compliance : Low
4. DLCO – Reduced
5. Blood gases

26. BRONCHO ALVEOLAR LAVAGE
1. Nonspecific
2. Narrow down diff. diagnosis
3. Defines stage of disease
4. Assessment of progression
5. Assessment of treatment response

27. ACTIVITY ASSESSMENT
1. Symptomatology
2. Chest radiography
3. Pulm. Function tests
4. BAL ? TBLB
5. Scanning – Ga-67,
TC99m DTPA

28. TREATMENT

29. Objectives of Treatment of ILDs
1. Symptomatic relief
2. Slow down disease progression
3. Prevent/ Treat complications
4. Prolong survival
5. Improve Quality of Life
6. Prevent drug-induced problems
7. End of Life Care

30. Treatment Principles
I. Secondary ILDs
Treatment of ILD of a known primary cause essentially comprises
the treatment of the primary disorder.
Symptomatic
Anti-inflammatory
Supportive
II. Primary ILD (Idiopathic Interstitial Pneumonias) and Pulmonary
Fibrosis

31. Treatment of IIP/IPF
 Of all IIPs, Idiopathic Pulmonary Fibrosis (IPF) i.e. U.I.P. is the
most common form.
 It is associated with an extremely poor prognosis for survival in
most patients.
 Life expectancy after diagnosis varies, but is on average less than 5
years.

32. Current Drug Treatment
1. Corticosteroids
2. Immunosuppressive drugs: Azathioprine,
Cyclophosphamide, Cyclosporine
3. Antifibrotic drugs: Pirfenidone, Colchicine, D-
penicillamine, Pentoxyfylline
4. Anti-oxidants: N. Acetyl-cysteine

33. Supportive Treatment
1. Underlying cause – Identification and management
2. Oxygen therapy
3. Management of pulmonary hypertension and cardiac failure
 Pulm. Vasodilators
 Diuretics
4. Antibiotics for infections
5. Miscellaneous

34. End Stage Disease
1. Lung Transplantation
2. Palliative End of Life Care
 Domicilliary Oxygen
 Symptomatic relief
 Discontinuation of steroids and immunosuppressive drugs

35. Sarcoidosis
 Multi-system granulomatous disorder
 Unknown etiology
 Pulmonary features > 80% (Interstitial infiltrates/fibrosis)
 Extrapulmonary (Eyes, skin, liver, spleen, nervous systme, cardiac
etc): Approx. 30%
 Increasing recognition
 Diagnosis primarily on lung biopsy; Serum ACE
 Treatment: Corticosteroids and other anti-inflammatory drugs

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