PULMONARY CROHNS DISEAS
– Recognized before, after or conmarch_03ly with the onset of bowel disease.
– Most commonly seen after onset of GI symptoms.
– Course and severity of pulmonary disease not necessarily related to activity of intestinal disease.
Types
of involvement:
–
Acute
alveolitis
–
Chronic
bronchitis
–
Bronchiectasis
–
Brochiolitis
obliterans with organizing pneumonia
–
Obstructive
disease
–
Bronchial
hyperresponsiveness
–
Interstitial
pneumonitis/ fibrosis
–
Granulomatous
lung disease
–
Inflammatory
tracheal stenosis
–
Lung
infiltrates with peripheral eosinophilia
–
Pulmonary
vasculitis
Typical
acute presentation and findings:
–
Cough
and breathlessness
–
Obstructive
lung disease of variable severity
–
Sometimes
restrictive pattern
–
Slight
or inconsistent response bronchodilators
–
CXR
often normal
–
Decreased
DLco
–
Increased
FRC and RV
–
Increased
bronchial reactivity
–
Alveolar
lymphocytosis
DLco
is typically reduced in acute presentation:
–
Reduction greater with exacerbation than in remission 1-3
–
Related to disease activity 1, 3
–
Not related to disease activity 4
–
Not related to disease severity 2
–
Not related to disease severity or activity 5-7
FRC
and not DLco affected in acute presentation:
–
FRC elevated and associated with disease activity 5
–
FRC elevated and associated with disease severity 8
Differential
diagnosis
The main differential diagnosis is extrapulmonary, intestinal involvement
of sarcoid
–
Non-caseating
epitheloid granulomas
–
Tendency
to fibrosis
–
Erythema
nodosum, arthritis, uveitis
–
Biopsy
to diagnose
–
Serum
ACE may be used to monitor but not good for diagnosis
–
Kveim
test is no longer in practice
–
Families
exist in which sarcoid and crohns disease conditions coexist. This plus
the similarities of the two conditions suggest the possibility of a
similar genetic predisposition
Outcome
–
Steroid
responsive
–
Pattern
and site of involvement usually remain same over time
–
Change
in degree of activity over time
–
Note
that colonic and bronchial epithelium are both derived from the primitive
gut
–
Respiratory
manifestations may develop if GI symptoms controlled or post coloproctectomy
–
Coloproctectomy
does not improve respiratory symptoms
Latent
Pulmonary changes that are seen in crohns disease
–
Alveolar
lymphocytosis
–
Activation
alveolar macrophages (superoxide generation)
–
Low
T1/2 DTPA clearance lungs
–
Increased
pulmonary vascular permeability
–
Abnormal
PFTs
WHAT IS THE CLINICAL SIGNIFICANCE OF THESE FINDINGS?
NEXT PAGE