Discussion
Diagnosis With Brief Discussion
- Diagnosis
- ABPA (Allergic BronchoPulmonary Aspergillosis)
- Radiologic Findings
- Chest radiograph shows multifocal, large areas of consolidation in the right perihilar region and both lower lung zones.
CT scans with lung window setting show multifocal areas of consolidation with bronchiectatic changes of the proximal airways.
CT scan with mediastinal window shows mucoid plugging within the ectatic bronchi (fluid bronchogram).
Laboratory Findings
Eosinophilia (+): 40% (3200)
IgE: 4454
ELISA for parasite (sparganosis, cysticercosis, PW, CS: all negative)
Skin test: Aspergillus niger (+)
Aspergillus Ab (+)
Bronchiectasis (+)
Asthma (+)
Serum titer for Aspergillus fumigatus (+): 1:2
Bronchoscopic Findings
Edematous, hyperemic bronchial mucosa with thick, whitish secretion
Washing Cytology:
Numerous eosinophils and Charcot-Leyden crystal with necrotic background
- Brief Review
- Major Criteria for ABPA:
1. Asthma
2. Blood eosinophilia
3. Immediate skin reactivity to Aspergillus antigen
4. Precipitin antibodies to Aspergillus antigen
5. Raised serum Ig E
6. History of radiographic pulmonary opacities
7. Central bronchiectasis
Minor Criteria for ABPA
1. A. fumigatus in sputum
2. History of expectorating brown plugs
3. Late skin reactivity to Aspergillus antigen
ABPA is a hypersensitivity reaction to Aspergillus species, commonly found fungi in soil. It occurs almost exclusively in patients with asthma or cystic fibrosis. The disease is the result of immunologic response to the endoluminal growth of species.
The diagnosis of ABPA is based on clinical, laboratory, and radiologic criteria. Primary criteria include asthma, radiologic evidence of pulmonary infiltration, positive skin test to A. fumigatus, eosinophilia, precipitating Ab to A. fumigatus, elevated IgE, elevated A. fumigatus-specific IgE and IgG, and central bronchiectasis. A diagnosis of ABPA is nearly certain when six of these eight criteria are fulfilled. But, many of these findings are nonspecific. Only central bronchiectasis is nearly pathognomomic and essential to diagnosis to most cases. The symptoms include cough, hemoptysis, fever, pleuritic pain, wheezing, and dyspnea.
In patients with ABPA, bronchiectasis is a sequel to mucoid impaction of central airway. Aspergillus proliferates in proximal bronchi, acting as an Ag stimulus for production of IgE and IgG Ab. Then the inflammatory reaction results in mucosal irritation, and eventually, damage to bronchial wall. Pathologically, central bronchi are distended with thick mucus, admixed with cellular debris and eosinophils. The bronchial wall shows inflammatory cell infiltrate without evidence of fungal invasion.
The characteristic radiologic findings are result of dilated bronchi with or without mucoid impaction and air-fluid levels; homogeneous, finger-like densities in a precise bronchial distribution, usually involves upper lobes and segmental or subsegmental bronchi. These opacities are described variably, such as "gloved-finger", "inverted Y or V", or "cluster of grapes" appearance. The CT often shows varicose or cystic mucoid impaction within the bronchi. ABPA, a hypersensitivity reaction in which organisms remain within airway lumen, should be differentiated from invasive aspergillosis, defined as angioinvasive and airway-invasive in immunocompromised patients.
- References
- Naidich DP, Webb RW, Muller NL, Krinsky GA, Zerhouni EA, Siegelman SS. Computed tomography and magnetic resonance of the thorax. 3rd ed. Philadelphia-New York: Lippincott-Raven, 1999:63-71
Fraser RG, Pare JAP, Pare PD, Fraser RS, Genereux GP. Infectious disease of the lungs. In: Fraser RG, ed. Diagnosis of Disease of the chest. 3rd ed. Philadelphia, Pa: Saunders, 1989; 996-1007
Neeld DA, Goodman LR, Gurney JW, Greenberger PA, Fink JN. Computerized tomography in the evaluation of allergic bronchopulmonary aspergillosis. Am Rev Respir Dis 1990; 142:1200-1205
- Keywords
- Airway, Lung, Eosinophilic lung disease, Fungal infection,