Allergy and intolerance
IgE antilichamen els
Antibodies against alder pollen; shows whether the immune system is sensitive to alder tree pollen, not whether it bothers you.
Everything about this testWhat it measures
The alder is a tree that often grows along water and on wet ground. It flowers early in the year, usually from January to March, and then releases a lot of pollen. Alder pollen is very similar to that of birch and hazel, so people who are sensitive to birch often also have antibodies against alder. This test measures the amount of IgE antibodies against alder pollen in the blood, in kU/l.
- Sensitization to alder pollen: the body has made IgE antibodies against alder pollen
- Support in working out hay fever that starts early in the year, together with the history of the symptoms
High
A value above the cut-off means that you have IgE antibodies against alder pollen: sensitization. That is not the same as an allergy. In people with symptoms such as sneezing, a blocked or runny nose, itchy or watery eyes or shortness of breath early in the year, often as early as January or February, a positive result fits hay fever from tree pollen. Because alder pollen is very similar to birch pollen, the result for birch is often positive as well; symptoms that continue into May then fit birch better. 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: in which months and where the symptoms occur, and whether there are symptoms in the mouth after eating fruit or nuts. With a positive result and matching symptoms, advice follows to reduce contact with pollen, such as keeping windows closed on dry, sunny days, and if needed medication for the nose and eyes. With a lot of symptoms despite medication, an allergist or ENT specialist can discuss immunotherapy, where the result for single allergens helps determine which pollen it targets.
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
Hay fever is common and often starts at a young age. According to the Longfonds (Dutch lung foundation), trees such as hazel, alder and birch cause symptoms from January to May; alder and hazel flower first. Sensitization is more common than the allergy itself.
Who is this useful for
Useful with symptoms of the nose, eyes or airways that come back every year early in the year, from January to March, especially outdoors on dry, mild days. Because alder, hazel and birch cross-react strongly, the result says the most together with the test for birch pollen and the history of the months in which you have symptoms. 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 hooikoorts
- Longfonds: Hooikoorts
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