Understanding Your Medical Test: What It Is, How It Works, and How to Prepare

Published: August 9, 2026Updated: August 16, 2026

This test measures whether your white blood cells release leukotrienes when exposed to Aspergillus fumigatus, a type of fungus, to help diagnose allergic conditions.

Quick summary

{"The test checks if your immune system reacts to Aspergillus fumigatus fungus","It measures leukotrienes released by white blood cells after exposure to the fungus","A positive result may indicate an allergic response or sensitivity","The test requires a blood sample","Results help doctors diagnose fungal allergies or related conditions"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC: 48241-4
Short code: A fumgtus LR-mCnc
Synonyms: A fumgtus LR-mCnc
Category: chemistry
Sample: serum
Container: Red-top tube (SST)
Units: N/A
Fasting: false
Population: adult
Sex: all
Age range: 18–65 years
Specimen volume: 5 mL
Stability: Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 4–24 hours
Order: routine

The Aspergillus fumigatus leukotriene release test is a laboratory test that measures the amount of leukotrienes released by your white blood cells (leukocytes) when they are exposed to Aspergillus fumigatus, a common mold/fungus found in the environment. Leukotrienes are chemicals produced by immune cells during allergic reactions and inflammatory responses.

How is this test performed, and what can I expect during the procedure?

A blood sample is taken from your vein. In the laboratory, your white blood cells are separated and exposed to extracts of Aspergillus fumigatus. If your immune system is sensitized to this fungus, your leukocytes will release leukotrienes in response. The amount of leukotrienes released is then measured.

Do I need to prepare for this test, and are there any steps I should take beforehand?

No special preparation is typically required. However, you should inform your doctor about any medications you are taking, as certain drugs (especially corticosteroids or antihistamines) may affect test results. It is best to have this test done before taking any new allergy medications if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

This test is primarily used to diagnose allergic bronchopulmonary aspergillosis (ABPA), a condition where the immune system overreacts to Aspergillus fungus in the lungs, causing breathing problems and lung damage. It may also be used to detect other fungal allergies, assess hypersensitivity in patients with asthma or cystic fibrosis, and differentiate between allergic and non-allergic respiratory conditions. Elevated leukotriene release suggests an IgE-mediated immune response to Aspergillus fumigatus.

Results are interpreted along with other clinical findings, including symptoms, chest X-rays, and other allergy tests. A positive result indicates sensitization to Aspergillus fumigatus, which may require treatment with antifungal medications and corticosteroids.

Frequently asked questions

What does a positive result mean?

A positive result indicates that your white blood cells release leukotrienes when exposed to Aspergillus fumigatus, suggesting you have an allergic sensitivity or reaction to this fungus. This may be associated with conditions like allergic bronchopulmonary aspergillosis (ABPA) or other fungal allergies.

What does a negative result mean?

A negative result suggests that your immune system does not react to Aspergillus fumigatus. However, a negative result does not completely rule out fungal allergy, as other testing methods may be needed for complete evaluation.

Is this test painful?

The test involves a simple blood draw, which may cause brief discomfort or a minor bruise at the needle site. Most people tolerate it well with minimal side effects.

How long does it take to get results?

Results typically take a few days to a week, as the test requires specialized laboratory processing to measure leukotriene release from white blood cells.

Who should have this test?

This test is usually ordered for patients with respiratory symptoms suggestive of fungal allergy, such as asthma or cystic fibrosis patients with worsening symptoms, individuals with suspected allergic bronchopulmonary aspergillosis, or those with unexplained lung infiltrates.

Sources

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy