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Allergic Bronchopulmonary Aspergillosis

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Allergic Bronchopulmonary Aspergillosis, ABPA

  • Epidemiology
  1. Worldwide Prevalence: 4 Million
  • Pathophysiology
  1. Immunologic disorder caused by Hypersensitivity to Aspergillus fumigatus
    1. Aspergillus fumigatus colonization of airways and mucus resulting in Asthma and Bronchiectasis
    2. A. fumigatus germinate into hyphae, resulting in T Cell response
    3. A. fumigatus is most common, but A. niger, A. flavus and A. clavatus may also cause ABPA
  2. Bronchial Asthma
    1. Due to IgE mediated Hypersensitivity
  3. Bronchiectasis
    1. Due to immune complex deposition in proximal airways
  • Risk Factors
  1. Cystic Fibrosis
  2. Asthma
  3. Immunocompromised State
  4. Genetic predisposition (esp. HLA-DR2 or HLA-DR5)
  • Symptoms
  1. General
    1. Anorexia
    2. Fatigue
    3. Generalized myalgias
    4. Low grade fever
    5. Weight loss
  2. Respiratory
    1. Wheezing (related to Asthma)
    2. Productive Cough
      1. Brown mucus plugs
      2. Blood-tinged Sputum
    3. Dyspnea
    4. Pleuritic Chest Pain
  • Signs
  1. Wheezing
  2. Rhonchi
  3. Rales (Bronchiectasis, esp. Cystic Fibrosis)
  • Labs
  1. Peripheral Eosinophilia
  2. Serum precipitans to a. fumigatus
    1. Serum Aspergillus >27 mg/L
  3. Serum IgE increased
    1. Total Serum IgE typically >1000 ng/ml
  4. Aspergillus skin test
    1. Immediate wheal and flare reaction to a. fumigatus
  • Imaging
  1. Chest XRay
    1. Recurrent and fleeting Pulmonary Infiltrates and Bronchiectasis primarily in the upper lobes
  2. High Resolution CT Chest
    1. Preferred to assist in diagnosis, exclude other causes, identify Bronchiectasis distribution
  • Diagnosis
  1. Multiple diagnostic protocols based on clinical presentation, lab and imaging
    1. Bronchial Asthma
    2. Central Bronchiectasis
    3. Fleeting Pulmonary Infiltrates
  2. ISHAM Criteria
    1. Bronchial Asthma or Cystic Fibrosis AND
    2. Type 1 Aspergillus skin test reaction or elevated serum IgE to A. fumigatus AND
    3. Two of three minor criteria positive
      1. Serum IgG or IgM Antibody to A. fumigatus
      2. Imaging opacities consistent with ABPA
      3. Total serum Eosinophils >500 IU/ml if steroid naive (otherwise >1000 IU/ml)
  • Management
  1. Early diagnosis and management offers best prognosis (before Bronchiectasis develops)
  2. Long-term use of Systemic Corticosteroids
    1. Starting at 0.5 to 1 mg/kg for first 2 weeks
    2. Slow taper over 3-5 months
  3. Oral Antifungals
    1. Itraconazole 200 mg twice daily for 16 weeks
      1. Often continued at 200 mg daily or every other day while Corticosteroid dependent
    2. Other Antifungals
      1. Voriconazole
      2. Posaconazole
  4. Other medications to consider
    1. Omalizumab (esp. in Asthma)
  • Compolications
  1. Severe, refractory Asthma
  2. Invasive Aspergillosis or chronic pulmonary Aspergillosis
  3. Pulmonary Fibrosis
  4. Emphysema
  5. Recurrent lung infection
  • References