Bronchiolitis obliterans: Why did we miss this earlier?

Report
Bronchiolitis obliterans:
A new disease?
Robert Gie, Pierre Goussard, Sharon Kling
Department Paediatrics and Child Health
Faculty of Health Sciences
Stellenbosch University
• 9 Month old girl referred pneumonia not
responding to treatment
• Normal antenatal and neonatal history
• No previous lower respiratory infections or
wheezing episodes
• Child needed intubation and ventilation
• Bilateral hyperinflation with wheezing
• Crepitations bilaterally
Course
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Ventilated for 17 days
• Adenovirus cultured from tracheal aspirate
• All other cultures was negative
• HIV negative
Follow - up
• Repeated episodes of lower respiratory
tract infections with wheezing
• No response on inhalation steroids
• Chronic hyperinflation
• Harrison sulci
• Persistent crepitations bilaterally
Bronchioloitis obliterans
• Associated with airway epithelial injury:
– Developed countries with transplant programs
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Allograft recipients
Collagen vascular disorders
Toxic fume inhalation
Chronic hypersensitivity pneumonitis
Drugs (penicilalamine, cocaine)
Steven Johnson syndrome
– Post infectious BO
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Adenovirus
Influenza virus
Respiratory syncitial virus
Mycoplasma pneumoniae
Post infectious Bronchiolitis
obliterans
• Commonest cause world wide
• World wide distribution unusual:
– Southern Hemisphere
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New Zealand
Argentina
Chile
Australia
South Africa
– Genetic predisposition
Clinical picture
Pathogenesis
• Other studies demonstrated increased
serum concentrations of interlukin-6 (IL6), IL-8, and tumor necrosis factor-alpha
(TNF-a), as well as decreased numbers of
T-lymphocytes, natural killer (NK), CD4þ
T, and B1 B-cells in children severely
affected by adenoviral pneumonia.
Diagnosis
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Clinical clues
Chest radiography
Radio-isotope studies
Chest computer tomography
Lung function tests
Lung biopsy
Swyer James /Macleod Syndrome
Lung perfusion scans. Lung perfusion scan of a 1.5-year-old boy 5
months after initial episode of AVB shows segmental
defects in the right upper lobe, middle lobe, and left lower lobe.
Lung biopsy
• Non-homogenous distribution of disease
• Sampling error
• Not the gold standard
Criteria for suspecting Bronchiolitis
Obliterans
1. Absence of respiratory illness during the
perinatal period and up to the onset of viral
illness
2. Severe Bronchiolitis in a previously healthy
infant requiring hospital admission, needing
additional oxygen and demonstrating low
oxygen saturation levels for more than a month
3. Following the acute phase of the ilness,
persistence for more than 3 months of
respiratory distress, signs of bronchial
obstruction and airtrapping , with arterial
oxygen saturations < 95%
Clinical criteria:
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Chronic persistent cough
Co-existent chronic pansinusitis
Course crackles
Bilateral small nodular disease on CXR/CT
FEV1/FVC < 70%
Cold agglutinins > 1:64
Treatment of Bronchiolitis
obliterans
• Fixed airway obstruction and poor response to
long-term steroid treatment.
• Supplemental oxygen to keep hemoglobin
saturation at or above 94%.
• Nutrition status.
• Chest physiotherapy: bronchiectasis.
• Exacerbations, usually due to viral infections,
demand a more aggressive approach with
liberal use of antibiotics, oral steroids and
bronchodilators.
• As an alternative to continuous oral steroids
required in patients with severe PBO, pulse
therapy with methylprednisolone (30
mg/kg/day) for three days monthly, has been
proposed.
Prognosis
• The overall prognosis for patients with PBO is
good.
• Some children, especially those who present
initially with respiratory failure, may develop
severe obstruction,hyperinflation and CO2
retention and may progress to cor pulmonale
With growth of the lungs, peripheral airway
conductance increases.
Clinical improvement observed in patients
with postinfectious BO may be due to
normal lung growth and not regression of
the pathology in the small airways.
Unanswered questions:
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Which children are predisposed to developing BO?
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Can BO be prevented during adenovirus pneumonia?
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What are the surrogate markers of disease progression?
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What are the exact criteria for making the diagnosis?
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What is the best treatment of BO?
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Should long-term immune modulation be used?
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What are the factors that determine prognosis?
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Should re-ventilation be considered?
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Why are we not reporting from SA?
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Does HIV infection influence BO?

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