interstitial lung diseses and idiopathic pulmonary fibrosis
Interstitial Lung diseases
Idiopathic Pulmonary fibrosis
Bannu Medical College Bannu.
A 19 years old boy presents
with the complaint of
productive cough, on
examination there are few
inspiratory crackles over the
upper zones of both lungs.
abdominal examination is normal…. His chest x ray z shown,,,,
,,he does not smoke…sputum microbiology report shows
scanty pseudomonas …. He also gives the history of repeated
chest infection and there is no family history of chest infection.
Interstitial lung diseases
A variety of acute & chronic lung diseases with
variable degrees of pulmonary inflammation &
fibrosis – ILDs
“Interstitial” is misnomer
– involves cellular &
interstitial components of
alveolar wall extending
into alveolar space –
Diffuse Parenchymal Lung
Idiopathic pulmonary fibrosis
form of chronic, progressive fibrosing interstitial
pneumonia of unknown cause, primarily occurring in older
adults, limited to the lungs, and associated with the
histopathologic and/or radiologic pattern of usual interstitial
According to American Thoracic
Society out Of the 7 listed
idiopathic interstitial pneumonias
Idiopathic pulmonary fibrosis
is the most common disease
Why is it bad?
• a poor prognosis,
• upto date, no proven effective therapies are
available for the treatment beyond lung
• 60% of patients with idiopathic pulmonary fibrosis
die from their idiopathic pulmonary fibrosis,
• mean survival of 2-5 years from the time of
• Death rates increase with increasing age, and are
consistently higher in men than women .
The previous theory
generalized inflammation progressed to widespread
parenchymal fibrosis. However, anti-inflammatory agents
and immune modulators failed in modifying the natural
course of the disease
The current theory
unknown endogenous or environmental stimuli disrupt the
homeostasis of alveolar epithelial cells, resulting in diffuse
epithelial cell activation and aberrant epithelial cell repair.
The etiology of idiopathic pulmonary fibrosis remains
undefined; however, in the current hypothesis , exposure
to following inciting agent in a susceptible host may lead
to the initial alveolar epithelial damage
• environmental pollutants,
• environmental dust,
• viral infections,
• gastroesophageal reflux disease,
• chronic aspiration
• Prostaglandin E2 deficiency
• Genetic basis
• Caveolin-1 deficiency
It is critical to obtain a complete history, including medication
history, social history, occupational history, exposure history, and
review of systems, to ensure other causes of interstitial lung disease
exertional dyspnea .
nonproductive cough .
obstructive sleep apnea
Associated systemic symptoms can occur but are not common. E.g
fine bibasilar inspiratory crackles (Velcro crackles).
involvement does not
occur with idiopathic
pulmonary fibrosis .
Pulmonary hypertension is a common co morbidity in patients with
idiopathic pulmonary fibrosis
American Thoracic Society –
• According to them, in immunocompetent
adult, the presence of all of the major
diagnostic criteria as well as at least 3 -4
minor criteria increases the likelihood of
correct diagnosis of IPF.
1. Exclusion of other known causes of ILD such
as certain drug toxicities, environmental
exposures & connective tissue disorders
2. Abnormal pulmonary function studies that
include restriction(reduced VC, increased
FEV1/FVC ratio ) and impaired gas exchange
3. Bibasilar reticular abnormalities with minimal
ground glass opacities on HRCT scans
4. Transbronchial lung biopsy or BAL showing no
features to support alternative diagnosis
1. Age > 50 yr
2. Insidious onset of otherwise unexplained
dyspnea on exertion
3. Duration of illness > or equal to 3 months
4. Bibasilar, inspiratory crackles ( dry /
velcro type in quality )
Results from routine laboratory studies are nonspecific for the
diagnosis of idiopathic pulmonary fibrosis; however, some
Routine lab Investigations are to rule out other causes of
1. Elevated ESR, hypergammaglobinemia may be foun
2. Positive anti nuclear antibodies / RA Factor occur in 10 -20 %
of cases, usually in low titres.
The chest radiograph lacks diagnostic specificity for
idiopathic pulmonary fibrosis.
The typical findings are
peripheral reticular opacities (netlike linear and
curvilinear densities) predominantly at the lung bases .
Honeycombing (coarse reticular pattern)
lower lobe volume loss can also be seen
High-resolution computed tomography
HRCT findings are significantly more sensitive and
specific for the diagnosis of idiopathic pulmonary
fibrosis . The typical findings are
1. Bilateral basal and subpleural reticulation .
Traction bronchiectasis .
Basal honeycombing with minmal ground glass
GGO – may be present but less extensive than reticular
Lobar volume loss – if advanced
reticular opacities (red circle) distributed in
both lung bases and the minimal ground-glass
opacities (blue circle).
Pulmonary function testing
Vital capacity, functional residual
capacity, total lung capacity, and forced vital
capacity (FVC) all are reduced.
Decreased diffusion capacity of carbon monoxide
a decline in DLCO greater than 15% over 1 year is
also associated with increased mortality.
6-Minute walk testing
used in the in clinical
assessment of patients
pulmonary fibrosis .
Desaturation below the
threshold of 88% during
the 6MWT has been
associated with an
Heart rate recovery (HRR)
specifically the failure of the heart rate to decline at 1
or 2 minutes postexercise, is associated with
BAL is not required for the diagnosis of idiopathic
pulmonary fibrosis; however, BAL fluid analysis can
be useful to exclude other alternative diagnoses .
Increased numbers of neutrophils in BAL fluid are
found in 70-90% of all patients with idiopathic
• Transthoracic echocardiography is an excellent modality
to detect pulmonary hypertension.
Surgical lung biopsy
• A surgical lung biopsy specimen can be obtained through
either an open lung biopsy or video-assisted
thoracoscopic surgery (VATS). VATS is preferred because
it is associated with less morbidity and a shorter hospital
stay compared with open lung biopsy.
In patients with UIP pattern on HRCT a surgical lung biopsy
is not needed for the diagnosis of idiopathic pulmonary
fibrosis. However, in patients with possible UIP pattern or
inconsistent with UIP pattern on HRCT, a surgical lung
biopsy is needed for the diagnosis of idiopathic pulmonary
Bronchoscopy with BAL and/or
transbronchial biopsy is not
required for the diagnosis of
idiopathic pulmonary fibrosis.
However, it can be used to
ensure that alternative
diagnoses are excluded.
Approach to the Diagnosis of
• Chest X-ray
• Surgical lung biopsy
The goal of is the assessment and treatment of comorbid medical
conditions. Common comorbid medical conditions e,g chronic
gastroesophageal reflux disease, and coronary artery disease.
Therefore, if any of these comorbid illnesses are present, they should
be managed according to current practice guidelines
Patients with hypoxemia
< 88%) at rest or with exercise should be prescribed
oxygen therapy to maintain a saturation of at least 90% at
rest, with sleep, and with exertion.
Vaccination against influenza and pneumococcal
infection should be encouraged in all patients with idiopathic
Sufficient clinical evidence is lacking to show
that any treatment definitely improves
survival / quality of life
Conventional treatment options:
in alone or combination
Cadaveric Lung transplantation for idiopathic pulmonary
fibrosis has been shows a survival benefit over medical
Guidelines for listing a patient for lung transplantation
1. diffusion capacity of carbon monoxide less than 39%
2. 10% or greater decrement in forced vital capacity during 6
months of follow-up,
3. decrease in pulse oximetry below 88% during a 6-minute
walk test (6MWT),
4. honeycombing on high-resolution computed
tomography (HRCT) imaging (fibrosis score >2
The following are complications that can be seen in
patients with idiopathic pulmonary fibrosis:
1. Pulmonary hypertension
2. Acute exacerbation of pulmonary fibrosis
3. Respiratory infection
4. Acute coronary syndrome
5. Thromboembolic disease
6. Adverse medication effects
7. Lung cancer
• A suspected patient should be referred to a pulmonologist
for further evaluation and management.
A diagnosed patient should be referred for lung
transplantation evaluation .
• Any patient
who is overweight should be encouraged to
meet with a nutritionist and make dietary changes to
achieve ideal body weight.
Maintaining adequate nutritional intake is important for
quality of life in patients with idiopathic pulmonary fibrosis
Regular activity improves walk distance and
symptoms or quality of life.
• Therefore, patients should be encouraged to
participate in regular exercise to maintain a maximal
degree of musculoskeletal conditioning.