Interstitial lung diseases

1. Interstitial Lung
Diseases
Dr. Rahul Magazine
M.D.(Medicine), D.T.C.D.
Department of Pulmonary Medicine

2. Definition
The interstitial lung diseases (ILDs) represent
a large number of heterogeneous disorders
that involve the parenchyma of the lung -- the
alveoli, the alveolar epithelium, the capillary
endothelium, and the spaces between these
structures, as well as the perivascular and
lymphatic tissues.

3. Classification
1. DPLD of Known Cause (drugs or
association such as collagen vascular
disease)
2. Idiopathic interstitial pneumonias
• Idiopathic Pulmonary Fibrosis (UIP pattern)
• IIP other than IPF (e.g. NSIP,DIP,AIP, RB-ILD, COP,
LIP)

4. 3. Granulomatous DPLD (Sarcoidosis)
4. Other forms of DPLD (e.g. LAM, PLCH)

5. EPIDEMIOLOGY
• Incidence 30 / 100000 per year (USA)
• Incidence higher in men

6. PATHOGENESIS
ILDs are the result of the superimposed
processes of inflammation and tissue injury and
attempted repair
Two major histopathologic patterns:
GRANULOMATOUS LUNG DISEASE
This process is characterized by an
accumulation of T lymphocytes, macrophages,
and epithelioid cells organized into discrete
structures (granulomas) in the lung
parenchyma. The granulomatous lesions can
progress to fibrosis.

7. INFLAMMATION AND FIBROSIS
The initial insult is an injury to the epithelial
surface causing inflammation in the air
spaces and alveolar walls. If the disease
becomes chronic, inflammation spreads to
adjacent portions of the interstitium and
vasculature and eventually causes interstitial
fibrosis.

8. CLINICAL PRESENTATION
HISTORY
 Breathlessness (most common): Initially,
dyspnea on exertion→ later at rest
 Nonproductive cough
 Fatigue
 Pleuritic chest pain
 Hemoptysis-- infrequent
 A family history of ILDs should be sought.

9. D/D BASED ON ONSET:
ACUTE ONSET: DAYS TO WEEKS
Acute interstitial pneumonia
Acute pneumonitis from collagen vascular
disease(especially SLE)
Diffuse alveolar hemorrhage
Hypersensitivity pneumonitis
CHRONIC: MONTHS TO YEARS
Idiopathic pulmonary fibrosis
Chronic hypersensitivity pneumonitis
Collagen vascular disease–associated ILD

10. PHYSICAL EXAMINATION
PULMONARY SIGNS
 With advanced disease, patients may have
tachypnea and tachycardia, even at rest.
 Bilateral, basilar, Velcro-like rales
 Signs of pulmonary hypertension

11.  EXTRAPULMONARY SIGNS:
Clubbing (e.g. IPF)
Skin abnormalities, peripheral
lymphadenopathy, hepatosplenomegaly
(SARCOIDOSIS)
Subcutaneous nodules (RHEUMATOID
ARTHRITIS)
Muscle tenderness and proximal weakness
(POLYMYOSITIS)

12. INVESTIGATIONS
CHEST RADIOGRAPHY
Nodules, linear (reticular) infiltrates, or a
combination of the two (reticulonodular
infiltrates)
Diffuse ground glass pattern– EARLY
Cystic areas (honeycomb pattern)-LATE

13. HIGH-RESOLUTION CT scan
PULMONARY FUNCTION TESTS
Reduced lung volumes, reduced diffusing
capacity (DLCO ),a normal or supernormal
ratio of FEV1 to FVC, Static lung
compliance is decreased (decreased lung
volume for any given transpulmonary
pressure), and maximal transpulmonary
pressure is increased (a very high
negative pressure must be generated to
open the fibrotic alveoli)

14. ARTERIAL BLOOD GAS ANALYSIS
BRONCHOSCOPIC STUDIES
Bronchoalveolar lavage
LUNG BIOPSY
Transbronchial biopsy
Open-lung or thoracoscopic biopsy

15. TREATMENT
Principal aims:
(1) to remove exposure to injurious
agents,
(2) to suppress inflammation to prevent
further destruction of the pulmonary
parenchyma, and
(3) to palliate the manifestations of these
diseases.

16. CORTICOSTEROIDS: mainstay of therapy
 Prednisone, 1 mg/kg for 1 month, followed by 40
mg/day given for 2 months
 Gradually tapered (5 mg/week) over several
months to a maintenance dose of 15 to 20
mg/day
 Corticosteroids are continued until pulmonary
function is stable for 1 year
 Relapses require returning to high-dose steroids
 Cytotoxic agents (Cyclophosphamide)or
immunosuppressive agents (Azathioprine) may
be used in patients who do not improve on
steroid therapy or who cannot tolerate
corticosteroids

17. Thank You