Smoking Related Interstitial Lung Diseases

06/26/1306/26/13 amr badreldin hamdyamr badreldin hamdy 11
Smoking Related ILDSmoking Related ILD
Amr Badreldin HamdyAmr Badreldin Hamdy
MD, FCCPMD, FCCP

They represent aThey represent a
heterogeneous group ofheterogeneous group of
lung disorders, generallylung disorders, generally
characterized bycharacterized by
dyspnea, dry cough,dyspnea, dry cough,
diffuse interstitialdiffuse interstitial
infiltrates, restrictive lunginfiltrates, restrictive lung
function pattern, andfunction pattern, and
impaired gas exchange.impaired gas exchange.

The majority of ILDThe majority of ILD
are of unknownare of unknown
cause, and knowncause, and known
causes includecauses include
gases, fumes, drugs,gases, fumes, drugs,
radiation, infections,radiation, infections,
inorganic dusts…etc.inorganic dusts…etc.

ILD positively associatedILD positively associated
with smoking:with smoking:
1. UIP/idiopathic pulmonary fibrosis.1. UIP/idiopathic pulmonary fibrosis.
2. Desquamative interstitial2. Desquamative interstitial
pneumonia.pneumonia.
3. Respiratory bronchiolitis-3. Respiratory bronchiolitis-
associated interstitial lung disease.associated interstitial lung disease.
4. Pulmonary Langerhan’s cell4. Pulmonary Langerhan’s cell
histiocytosis.histiocytosis.

Respiratory bronchiolitisRespiratory bronchiolitis
is extremely common inis extremely common in
cigarette smokerscigarette smokers
(smoker’s bronchiolitis).(smoker’s bronchiolitis).
Bronchiolitis is a genericBronchiolitis is a generic
term used clinically toterm used clinically to
describe variousdescribe various
inflammatory diseases ofinflammatory diseases of
small airways.small airways.

It usually occursIt usually occurs
without symptoms orwithout symptoms or
significant interstitialsignificant interstitial
lung disease.lung disease.
It may account forIt may account for
sub-clinical radiologicalsub-clinical radiological
changes in up to onechanges in up to one
fifth of smokers.fifth of smokers.

Although respiratoryAlthough respiratory
bronchiolitis occurs inbronchiolitis occurs in
virtually all smokers itvirtually all smokers it
is of little clinicalis of little clinical
significance in the vastsignificance in the vast
majority of cases.majority of cases.

ILD negativelyILD negatively
associated withassociated with
smokingsmoking::
1. Hypersensitivity1. Hypersensitivity
pneumonitispneumonitis
(exogenous allergic(exogenous allergic
alveolitis).alveolitis).
2. Sarcoidosis.2. Sarcoidosis.

1.1.
Occupational/Environmental.Occupational/Environmental.
2. Granulomatous diseases.2. Granulomatous diseases.
3. Iatrogenic/drug induced.3. Iatrogenic/drug induced.
4. Collagen-vascular4. Collagen-vascular
diseases.diseases.
5. Inherited.5. Inherited.
6. Unique entities.6. Unique entities.
7. Idiopathic interstitial7. Idiopathic interstitial

Without a completeWithout a complete
thorough clinicalthorough clinical
evaluation, all ILDevaluation, all ILD
are of unknownare of unknown
causecause..

IdiopathicIdiopathic
Pulmonary FibrosisPulmonary Fibrosis

The role of smoking inThe role of smoking in
the pathogenesis of IPF isthe pathogenesis of IPF is
controversial. It appearscontroversial. It appears
to increase the risk ofto increase the risk of
development of IPF, butdevelopment of IPF, but
there is no evidence thatthere is no evidence that
smoking per se directlysmoking per se directly
leads to the developmentleads to the development
of IPF.of IPF.

Usually sporadic or familial.Usually sporadic or familial.
Male to female ratio 2 to one.Male to female ratio 2 to one.
Bilateral reticular orBilateral reticular or
reticular-nodular opacitiesreticular-nodular opacities
with small lung volumes.with small lung volumes.
Typically lower zone andTypically lower zone and
peripheral predominance inperipheral predominance in
the distribution.the distribution.

HRCT showsHRCT shows
irregular linearirregular linear
opacities andopacities and
honeycombing,honeycombing,
predominantly in thepredominantly in the
base and sub-pleuralbase and sub-pleural
lung.lung.

PFT usuallyPFT usually
demonstrates ademonstrates a
restrictive defect withrestrictive defect with
reduced lung volumesreduced lung volumes
and diffusing capacity.and diffusing capacity.
Exercise-induced de-Exercise-induced de-
saturation is almostsaturation is almost
always seen.always seen.

In patients with pre-existingIn patients with pre-existing
emphysema, the lungemphysema, the lung
volumes and flow rates mayvolumes and flow rates may
be normal due tobe normal due to
counteracting physiologicalcounteracting physiological
effects of emphysema andeffects of emphysema and
fibrosis.fibrosis.
In such patients, PFT mayIn such patients, PFT may
only reveal a severelyonly reveal a severely
reduced diffusing capacityreduced diffusing capacity..

DesquamativeDesquamative
Interstitial PneumoniaInterstitial Pneumonia

Ninety percent areNinety percent are
smokers or ex-smokers.smokers or ex-smokers.
May occasionally beMay occasionally be
seen in association withseen in association with
systemic disorders orsystemic disorders or
infections, as well asinfections, as well as
exposure toexposure to
occupational/environmentoccupational/environment
al agents and drugs.al agents and drugs.

Average age of onset isAverage age of onset is
40 years.40 years.
Male predominance (2:1).Male predominance (2:1).
Inspiratory crackles areInspiratory crackles are
heard in 60%.heard in 60%.
Digital clubbing in nearlyDigital clubbing in nearly
50%.50%.

On chest X-ray lungOn chest X-ray lung
volume appearsvolume appears
reduced unless therereduced unless there
is co-existent OADis co-existent OAD
such as smokerssuch as smokers
with emphysema.with emphysema.

Predominant finding byPredominant finding by
HRCT is the presence ofHRCT is the presence of
areas of ground-glassareas of ground-glass
attenuations, typicallyattenuations, typically
sub-pleural and lowersub-pleural and lower
lung zone predominance.lung zone predominance.
Honeycombing is usuallyHoneycombing is usually
not present.not present.

R-BILDR-BILD

It is a clinicalIt is a clinical
pathological entity seenpathological entity seen
almost exclusively inalmost exclusively in
current or formercurrent or former
smokers.smokers.

PFT may be normal, butPFT may be normal, but
more commonly show amore commonly show a
mixed obstructive-restrictivemixed obstructive-restrictive
pattern of a mild-to-pattern of a mild-to-
moderate degree.moderate degree.
Reduced diffusing capacityReduced diffusing capacity
is common.is common.
TLC may be normal, mildlyTLC may be normal, mildly
increased or mildly reduced.increased or mildly reduced.

Diffuse, fine reticular orDiffuse, fine reticular or
are present in more thanare present in more than
2/3.2/3.
Ground-glass pattern mayGround-glass pattern may
be the predominantbe the predominant
abnormality.abnormality.
There is no honeycombingThere is no honeycombing
(DD IPF).(DD IPF).

Areas of ground-glassAreas of ground-glass
attenuation are theattenuation are the
most common findingmost common finding
((smoker’s alveolitissmoker’s alveolitis ).).
Micro-nodules may beMicro-nodules may be
present ( = respiratorypresent ( = respiratory
bronchiolitis).bronchiolitis).

Pulmonary Langerhan’sPulmonary Langerhan’s
Cell HistiocytosisCell Histiocytosis

The isolated pulmonaryThe isolated pulmonary
form in adults occursform in adults occurs
almost exclusively inalmost exclusively in
cigarette smokers. Adultcigarette smokers. Adult
PLCH represents aPLCH represents a
polyclonal, reactivepolyclonal, reactive
disorder triggered bydisorder triggered by
cigarette smoking.cigarette smoking.

Most patients are young adults (30-Most patients are young adults (30-
40y).40y).
Sex distribution is equal.Sex distribution is equal.
Ninety or more are current orNinety or more are current or
previous cigarette smokers.previous cigarette smokers.
The bronchiolar distribution ofThe bronchiolar distribution of
pathological lesions is consistentpathological lesions is consistent
with the possibility that an inhaledwith the possibility that an inhaled
antigen is involved in theantigen is involved in the
pathogenesis of this disorder.pathogenesis of this disorder.

Physical examinationPhysical examination
frequently normal.frequently normal.
Cystic bone lesionsCystic bone lesions
in 10% (skull, ribs,in 10% (skull, ribs,
pelvis).pelvis).
Diabetes insipidus inDiabetes insipidus in
10%.10%.

PFT show bothPFT show both
obstructive and restrictiveobstructive and restrictive
changes (effects fromchanges (effects from
cigarette smoking may becigarette smoking may be
superimposed andsuperimposed and
difficult to distinguishdifficult to distinguish
from effects of PLCHfrom effects of PLCH
itself).itself).

Typical finding on CXRTypical finding on CXR
include nodular orinclude nodular or
most prominent in themost prominent in the
middle and upper lungmiddle and upper lung
zones, usually sparing ofzones, usually sparing of
the costo-phrenic anglesthe costo-phrenic angles
Lung volumes appearLung volumes appear
normal or increased.normal or increased.

HRCT show thin-HRCT show thin-
walled cysts, noduleswalled cysts, nodules
(with or without(with or without
cavitation) or acavitation) or a
combination of nodulescombination of nodules
and cysts.and cysts.

PrognosisPrognosis

IPFIPF
Response toResponse to
steroids is poor.steroids is poor.
Prognosis is poorPrognosis is poor
with no possibility ofwith no possibility of
complete recovery.complete recovery.

DIPDIP
Most patients remainMost patients remain
stable or improve withstable or improve with
corticosteroid therapycorticosteroid therapy
and complete recoveryand complete recovery
is possible.is possible.

R-BILDR-BILD
Good prognosis,Good prognosis,
particularly with smokingparticularly with smoking
cessation.cessation.
Good response toGood response to
corticosteroid therapy andcorticosteroid therapy and
complete recovery iscomplete recovery is
possiblepossible..

PLCHPLCH
Smoking cessation maySmoking cessation may
prevent progression of theprevent progression of the
disease.disease.
Response to steroids isResponse to steroids is
fair.fair.
Complete recovery isComplete recovery is
possible.possible.
Prognosis is good.Prognosis is good.

ConclusionConclusion

• Smoking history is important inSmoking history is important in
ILD.ILD.
• Quitting smoking is importantQuitting smoking is important
in ILD.in ILD.
• ILD may accompany COPD.ILD may accompany COPD.
• HRCT may be of help inHRCT may be of help in
patients with COPD notpatients with COPD not
responding to usual broncho-responding to usual broncho-
dilator therapy. They may needdilator therapy. They may need
to add corticosteroids to theirto add corticosteroids to their
regimens.regimens.

• This may explain why soThis may explain why so
many patients with COPDmany patients with COPD
need corticosteroids inneed corticosteroids in
their treatment protocol.their treatment protocol.
• The incidence ofThe incidence of
smoking in the smokingsmoking in the smoking
related ILD reaches 90%,related ILD reaches 90%,
the same incidence as forthe same incidence as for
COPD.COPD.

THANK YOUTHANK YOU

Smoking Related Interstitial Lung Diseases

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