Allergy and intolerance
IgE antilichamen roggepollen
Antibodies against pollen from rye, a cereal; shows whether the immune system is sensitive to this pollen, not whether it bothers you.
Everything about this testWhat it measures
Rye (Secale cereale) is a cereal grown as a crop. It is a grass species, and its pollen is very similar to that of wild grasses. This test measures the amount of IgE antibodies against rye pollen in the blood, in kU/l; it concerns pollen in the air, not rye flour or rye bread. IgE is the type of antibody that, in an allergic reaction, triggers mast cells to release histamine; the body only makes these antibodies after it has previously been in contact with the allergen, and this is called sensitization.
- Sensitization to rye pollen: the body has made IgE antibodies against rye pollen
- Support in working out suspected hay fever from grass or cereal pollen, together with the history of the symptoms
High
A value above the cut-off means that you have IgE antibodies against rye pollen: sensitization. That is not the same as an allergy. Because rye pollen is very similar to grass pollen, a positive result in people with symptoms during the grass season usually fits hay fever from grass pollen in general, and rarely rye alone. People who live or work near rye fields may have more symptoms when it flowers. A positive result says nothing about an allergy to food containing rye; that is a different allergy.
Low
A value below the cut-off means that no IgE antibodies against rye pollen were found. Hay fever from rye pollen is then unlikely; for grass pollen in general, the result for timothy grass says more. Symptoms in another season more likely fit something else: tree pollen mainly causes symptoms in spring, pollen from weeds such as mugwort in late summer, and house dust mite, animals or mold can cause symptoms all year round.
If your result is abnormal
The GP mainly looks at the history: in which months and where the symptoms occur. 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; the result therefore only means something if it fits when and where you have symptoms. Rye pollen cross-reacts strongly with grass pollen; a positive result for rye usually adds little in someone who is also positive for timothy grass. 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.
- Rye pollen cross-reacts strongly with grass pollen; the test does not show whether the symptoms come from rye or from other grasses.
- The test concerns pollen in the air and says nothing about an allergy to rye flour or products containing rye.
- 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), the grass pollen period from May to August is the period with the most symptoms for many people; rye, as a grass species, flowers in the same part of the year. Sensitization is more common than the allergy itself.
Who is this useful for
Useful as an addition with symptoms of the nose, eyes or airways that come back every year in late spring and summer, for example if you live or work near cereal fields. For grass pollen in general, timothy grass says more. In people without such symptoms, the test adds nothing: sensitization without symptoms is not a disease and is not treated.
Downsides and risks
- A positive result can wrongly give the impression that you should avoid rye or rye bread; the test concerns pollen, not food.
- A normal result does not rule out hay fever from other grasses.
Sources
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