This document discusses the diagnosis of interstitial lung disease (ILD). It defines ILD as a collection of over 100 lung disorders that share clinical, radiographic, and pathological features. ILD is classified based on patterns seen on histology and radiography. Risk factors include age, smoking, occupation, and family history. Signs and symptoms include dyspnea, cough, chest pain, and digital clubbing. Diagnostic tests involve pulmonary function tests, chest imaging like HRCT, bronchoscopy, and surgical lung biopsy. HRCT is more sensitive than chest x-rays and can identify patterns like ground glass opacities and cysts that indicate different diseases.

1. DIAGNOSIS OF INTERSTITIAL
LUNG DISEASE
ANUSHA CM

2. 1. DEFINATION
2. CLASSIFICATION
3. PATHOGENESIS
4. HISTORY AND RISK FACTORS
5. SIGNS AND SYMPTOMS
6. LABORTORY EVALUATION
7. RADIOGRAPH
8. BRONCHOSCOPY
9. SURGICAL LUNG BIOPSY

3. PULMONARY INTERSTIUM
Interstitial compartment is
the portion of the lung
sandwiched between the
epithelial and endothelial
basement membrane
Expansion of the interstitial
compartment by
inflammation with or
without fibrosis

4. DEFINITION
• ILD refers to a heterogeneous collection of
more than one hundred distinct lung
disorders that tend to be grouped together
because they share clinical, radiographic, and
pathologic features

5. PATHOGENESIS
• Few cells in the interstitium of the normal lung
• Injury to basement membrane shared by epithelium and
endothelium
• Increased alveolar permeability and spillage of serum
contents into the alveolar space and recruitment of
fibroblasts
• Collagen deposition
• Also injury to small airways=respiratory bronchioles, alveolar
ducts and terminal bronchioles

6. CLASSIFICATION

7. RISK FACTORS
1.AGE
• Age 20-40 years - Sarcoidosis, CTD, LAM
• > 50years - Idiopathic pulmonary fibrosis

8. 2. SMOKING
Diseases associated with smoker:
• EG (histocytosis X)
• Desquamative interstitial pneumonitis
• Respiratory broncholitis
Diseases less likely to be seen in smoker:
•
• Hypersensitivity pneumonitis
• Sarcoidosis

9. 3. OCCUPATION

10. 4. FAMILY HISTORY
• Autosomal dominant pattern:
IPF
Sarcoidosis
Neurofibromatosis- I
Hermansky–Pudlak syndrome
Burt–Hogg–Dubé syndrome
• Autosomal recessive pattern:
Gauchen’s disease
Neimann pick

11. DRUG INDUCED ILD

12. SYMPTOMS
• Dyspnea- predominent symptom
• Cough(dry )- Second most frequent symptom. In sarcoidosis,
HP or organising pneumonia
• Substernal chest pain - sarcoidosis.
• Wheezing- hypersensitivity pneumonitis, eosinophilic
pneumonia, or sarcoidosis.
• Pleuritic chest pain- Connective tissue disease, or
pneumothorax in cystic lung diseases such as
lymphangioleiomyomatosis (LAM) and Langerhans cell
histiocytosis (LCH).

13. • Hemoptysis - diffuse alveolar hemorrhage, pulmonary veno-
occlusive disease, mitral stenosis, LAM, granulomatous
vasculitides.
• New onset of hemoptysis in a patient with known ILD
suggests a complicating malignancy.
• Gastrointestinal symptoms - indicative of underlying
esophageal motility problems related to connective tissue
disease like systemic sclerosis and polymyositis In particular,
symptoms suggestive of acid reflux chest burning or pressure,
cough after meals, regurgitation of food
• Bloating and diarrhea - inflammatory bowel disease or
bacterial overgrowth due to bowel dysmotility in systemic
sclerosis.

14. • Arthralgias, morning stiffness, joint swelling and erythema,
and deformities points towards Rheumatoid arthritis, Sjögren
syndrome or mixed connective tissue disorder
• Swollen fingers (“sausage digits”) -systemic sclerosis and
polymyositis.
• Raynaud’s phenomenon - Associated with digital ulcerations
and, rarely, digital gangrene: suggestive of underlying
scleroderma, mixed connective tissue disease, SLE, and
antisynthetase syndrome

15. • Ophthalmologic symptoms- dry eyes or the use of eye drops
may uncover sicca syndrome, as seen in Sjögren syndrome
and overlap connective tissue diseases.
• Uveitis - SLE or sarcoidosis
• Neurologic symptoms -vasculitis or sarcoidosis.
• Oculocutaneous albinism and colitis points to Hermansky
pudlak syndrome

16. SAUSAGE DIGITS IN SYSTEMIC SCLEROSIS

17. DURATION OF SYMPTOMS
• Acute (less than 3 weeks) (e.g. drug reaction, acute
hypersensitivity Pneumonitis, chemical exposure)
• Subacute: 3-12 weeks (e.g. COP)
• Insidious over months or years (e.g., IPF)

19. SIGNS
• Velcro crepts- B/L basal inspiratory- common in most forms
of ILD. Less likely to be heard in sarcoidosis.
• Inspiratory squeaks and wheeze- Bronchiolitis/ and
obstruction
• Clubbing: most commonly seen in IPF but non-specific.
• Cor pulmonale
• Cyanosis in late stage of ILD.
• Skin thickening and acral cyanosis- scleroderma

20. • Cutaneous vasculitis- churg strauss syndrome
• Edematous cyanotic skin- Dermatomyositis
• Palpable lymph nodes , hepatosplenomegaly - suggests
Sarcoidosis, HIV infection or CTD

21. LAB TESTS
• CBC, MR, LFT, ANA PROFILE, c ANCA, p ANCA, RA factor
• Peripheral eosinophilia > 10%
Churg-Strauss syndrome
Chronic eosinophilic pneumonia
• Serum precipitating antibodies: Hypersensitivity pneumonitis

23. PULMONARY FUNCTION
Most of the ILD have a restrictive defect.
Mixed pattern:
• Sarcoidosis
• Hypersensitivity Pneumonitis (HP)
• Histocytosis X
• Lymphangioleiomyomatosis (LAM)
• Wegener’s granulomatosis
• Broncholitis obliterans organizing pneumonia
(BOOP) rarely present with mixed pattern

24. • Moderate - severe reduction in DLCO but normal lung
volumes in a patient with ILD suggest:
• COPD with ILD
• Pulmonary Vascular Disease
• Pulmonary histocytosis X
• Lymphangioleiomyomatosis
• A reduction in DLCO is common but nonspecific.
• The severity of the DLCO reduction does not correlate well
with disease stage.
• During follow up , esp in IPF about 5-10% reduction in FVC
over 6 months is indicative of increased mortality

25. CHEST RADIOGRAPH
• Chest radiograph is normal in 10% of patients with ILD
(particularly those with HP).
• A diffuse reticulonodular pattern , ground glass opacities or
both are most common findings on radiograph

28. DISTRIBUTION OF ILD

29. HRCT FINDINGS
• High-resolution computed tomography (HRCT) of the chest is
significantly more sensitive than chest radiograph for
abnormalities in ILD.
• The characteristic radiographic features of IPF are collectively
known as the “UIP pattern,” since these features have been
demonstrated to confidently predict the presence of
pathologic UIP when surgical biopsy is obtained
• This pattern consists of peripheral, subpleural, basilar-
predominant reticular opacities in combination with basilar
honeycombing and without features, such as ground-glass
opacities, cysts or nodules, to suggest another form of ILD

30. • Composite physiologic index (CPI) reflects the extent of
fibrosis in HRCT
• An increase in CPI indicates progression of fibrosis and is
associated with increased mortality

31. PATTERN OF ILD

32. GROUND GLASS PATTERN
Hyper sensitivity
Pneumontis
PCP pneumonia
Diffuse Interstitial
Pneumonia
Non Specific Intersititial
Pneumonia
Alveolar hemorrhage

33. CYSTS OR CYST LIKE
LAM Bronchiectasis

34. NSIP pattern in a 64-year-old man. HRCT features of NSIP include extensive ground-glass areas in the lung (black arrows) and traction
bronchiectasis.

35. COP pattern in a 53-year-old man. HRCT images show characteristic
peripheral and bronchocentric consolidations. The “air bronchogram sign” is
clearly recognisable in A. Tendency to migration and changing location are
also typical imaging findings of COP

36. Acute interstitial pneumonia- bilateral dependent ground glass opacity

37. Diffuse interstitial pneumonia- ground glass densities with mosaic pattern.
These are reversible and disappear with smoking

38. RB-ILD: Ground-glass opacity and centrilobular nodules

39. ATS/ERS International IPF
guidelines

41. • In particular, a peripheral reticular pattern, that is basilar
predominant may be seen in IPF, NSIP, and connective tissue
disease– associated ILD
• Nodular infiltrates may suggest sarcoidosis, hypersensitivity
pneumonitis, and LCH
• The finding of diffuse cystic abnormalities leads to a specific
differential diagnosis, including LAM, LCH, and LIP
• The term “ground glass” refers to areas of lung tissues with
increased attenuation, but not enough to obscure or distort
lung architecture, blood vessels, and lymphatics
• Alveolar opacities are a related finding and reflect more
dense attenuation of lung tissue, sometimes containing air
bronchograms

46. BRONCHOSCOPY
• Includes BAL, TBLB, TBNA for cytologic or histological analysis
• Endobronchial lesions:
- Sarcoidosis
- Wegener’s granulomatosis - Inflammation and
stricture of the major airways
• Transbronchial bx: Sarcoidosis (75-80%)
Lymphangitic carcinomatosis (80%)
Eosinophilic pneumonia
Pulmonary alveolar proteinosis
Pulmonary histocytosis X
Good pasture’s syndrome
LCH
Lymphoid interstitial pneumonia

47. BAL: normal count:
- CD4:CD8 = 1.5
- Macrophage 85%
- Lymphocyte 5-10%
- Neutrophils < 2%
- Eosinophils < 1%
• Lymphocytic BAL (>30%): Sarcoidosis or hypersensitivity
pneumonitis.
• Neutrophilic BAL (>60%): Infection or ARDS
• Eosinophilic BAL (>30%): Acute or chronic eosinophilic
pneumonia; coccidioidomycosis

48. • Elevated CD4/CD8 ratio >2 in early, active sarcoidosis (may
be lower in chronic or quiescent disease)
• CD4/CD8 < 1 in hypersensitivity pneumonitis.
• The utility of BAL in the clinical assessment of disease
progression or response to therapy still to be established.

49. • In several patients with probable or possible IPF,
bronchoscopy may be used to rule out alternative diagnoses
like HP esp if VATS biopsy is too risky like in elderly patients
• However especially in IPF , bronchoscopy and BAL have the
potential of triggering acute exacerbation of IPF , so that the
indication for bronchopic evaluation should be discussed in
critically in every individual patient

50. SURGICAL BIOPSY
• Not required to make the diagnosis in all patient with ILD.
• However, it is not frequently possible to reach a definitive
diagnosis or to stage a disease without examination of lung
tissue.
• In IPF , histologic analysis from surgical biopsy is no longer
golden standard due to sampling error and no uniformity of
disease pattern in advanced cases
• Video-assisted thoracoscopic lung biopsy is the
preferred method of obtaining lung tissue.
• Consiquently in IPF , multidisciplinary discussion (MDD)
involving the pulmonologist, pathologist and radiologist has
become the gold standard for diagnosis

52. THANK YOU