Allergy and intolerance
IgE antilichamen Aspergillus fumigatus
Antibodies against the mold Aspergillus fumigatus; shows whether the immune system is sensitive to it, not whether it bothers you.
Everything about this testWhat it measures
Aspergillus fumigatus is a mold that is common in compost, rotting plant material, hay and potting soil, and indoors in damp places. Everyone regularly breathes in spores; in most people this causes no symptoms. This test measures the amount of IgE antibodies against Aspergillus fumigatus in the blood, in kU/l. The body only makes these antibodies after it has previously been in contact with the allergen; this is called sensitization. The test says nothing about an infection with Aspergillus; other tests exist for that.
- Sensitization to the mold Aspergillus fumigatus: the body has made IgE antibodies against it
- Support in working out a suspected mold allergy, together with the history of the symptoms, especially with asthma or with symptoms when working with compost, hay or potting soil
High
A value above the cut-off means that you have IgE antibodies against Aspergillus fumigatus: sensitization. That is not the same as an allergy. In people with nose or eye symptoms, coughing or shortness of breath when working with compost, hay or potting soil, or in a home with damp and mold patches, a positive result can fit an allergy to this mold. If you have asthma that is poorly controlled, a positive result can be a reason for referral to a lung specialist, who looks further into whether the mold plays a role. In people without such symptoms, a positive result only means that the antibodies are there; no treatment follows.
Low
A value below the cut-off means that no IgE antibodies against this allergen were found. An IgE-mediated allergy to this allergen is then much less likely, although it is not completely ruled out. Symptoms can also come from another allergen that was not tested, or have a non-allergic cause.
If your result is abnormal
The GP mainly looks at the history: when and where the symptoms occur, and whether there is asthma. With a positive result and matching symptoms, the advice is mainly about limiting contact with molds, for example by tackling damp and mold patches at home, ventilating well and avoiding dust when working with compost or potting soil. With poorly controlled asthma, especially with sensitization to Aspergillus fumigatus, referral to a lung specialist may follow.
Reliability
A positive IgE result shows sensitization, not allergy: it only says that there are antibodies, not that you get symptoms from them. The Dutch medical specialists' guideline (FMS) on upper airway allergy says this literally and recommends choosing a test for single allergens based on the history of the symptoms; for food allergy, the FMS guideline on food challenge testing calls the history of the symptoms the cornerstone of diagnosis and a food challenge in hospital the gold standard. The result therefore only means something if it fits when, where and after contact with what you get symptoms. A positive result without symptoms is not treated.
Limitations
- Sensitization without symptoms is common; the result can only be interpreted together with the history of the symptoms.
- Related allergens can recognize each other's antibodies (cross-reaction), for example pollen and nuts or fruit; a positive result then does not mean that this particular allergen causes the symptoms.
- The test measures all proteins from the allergen source together; testing for individual proteins (components) can say more in case of doubt.
- Laboratories use different measurement methods and cut-off values; results from different labs cannot be compared one to one.
How common is this
Molds are, alongside pollen, house dust mite and pets, a known cause of allergic nasal symptoms. Mold allergy is less common than allergy to pollen or house dust mite. Sensitization is more common than the allergy itself.
Who is this useful for
Useful with nose or eye symptoms, coughing or shortness of breath that fit molds: when working with compost, hay or potting soil, or in a home with damp and mold patches. Also with asthma that is poorly controlled, as an addition to the assessment by the GP or lung specialist. In people without such symptoms, the test adds nothing: sensitization without symptoms is not a disease and is not treated.
Sources
- NVKC, allesovertesten.nl: Allergie (RAST)
- FMS Richtlijnendatabase: Allergie van de bovenste luchtwegen, module Aanvullende diagnostiek
- FMS Richtlijnendatabase: Voedselprovocatie, module Plaatsbepaling diagnostiek voedselallergie
- Thuisarts.nl: Ik heb allergie
- Thuisarts.nl: Ik heb lange tijd of vaak neusklachten door een allergie
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results