Aspergillus-Specific IgE
Aspergillus-specific IgE detects IgE antibodies against Aspergillus species, especially A. fumigatus. It is the key test for evaluating allergic bronchopulmonary aspergillosis (ABPA) — a hypersensitivity reaction to Aspergillus colonizing the airways — and for confirming Aspergillus allergy in asthmatic or cystic fibrosis patients. Aspergillus-specific IgE, along with Aspergillus precipitins (IgG), total IgE, eosinophil count, and chest imaging, makes up the ABPA diagnostic panel.
Reference Ranges
Male
0 – 0.35
kU/L
Female
0 – 0.35
kU/L
Child
0 – 0.35
kU/L
Reference ranges may vary by laboratory. Always compare with the range printed on your lab report.
What Low Levels Mean
A negative Aspergillus-specific IgE effectively rules out ABPA. In a patient with asthma and unexplained bronchiectasis or eosinophilia, a negative result shifts workup to other causes: eosinophilic granulomatosis with polyangiitis, parasitic infection, non-tuberculous mycobacteria, or non-allergic asthma.
What High Levels Mean
Positive Aspergillus-specific IgE confirms sensitization. In an asthmatic with central bronchiectasis and very high total IgE, it is a key criterion for ABPA. In cystic fibrosis, positive Aspergillus IgE is common and interpreted alongside lung function, total IgE, and imaging. In severe asthma, sensitization to multiple fungi (including Aspergillus) defines the SAFS phenotype (severe asthma with fungal sensitization) and may guide antifungal therapy.
Frequently Asked Questions
What is ABPA and who gets it?
Allergic bronchopulmonary aspergillosis — a hypersensitivity response to Aspergillus colonizing the airways. Mostly affects patients with poorly controlled asthma or cystic fibrosis. In India, ABPA is increasingly recognized, especially in monsoon-prone regions. Typical features: brittle asthma, high total IgE (>1000 IU/mL), positive Aspergillus-specific IgE, positive Aspergillus precipitins, eosinophilia, and central bronchiectasis on CT.
How is ABPA treated?
Oral corticosteroids (prednisolone) are first-line for acute ABPA flares and effectively suppress the inflammation. Long-term management may include itraconazole or voriconazole as steroid-sparing antifungal therapy. Monitoring total IgE levels tracks disease activity — persistent decline after treatment indicates response, a rebound suggests relapse.
Can Aspergillus cause invasive infection too?
Yes — but it is a different disease. Invasive aspergillosis affects severely immunocompromised patients (stem cell transplant, solid organ transplant, prolonged neutropenia, advanced HIV, high-dose steroid use). It causes pneumonia, sinusitis, and disseminated disease. It is not an allergic reaction and is not diagnosed by IgE — it is diagnosed by imaging, galactomannan antigen, PCR, and culture.
This information is for educational purposes only and should not replace professional medical advice. Always consult your doctor for interpretation of your test results.
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