Relevance of Major Allergens in Weed Pollen Allergy

Weed pollen allergy is an important and in prevalence increasing cause of pollinosis in Europe and across the world. In this study we focus on the value of common diagnostic tools for detection of a sensitization to mugwort and English plantain, especially with regard to the clinical relevance of the sensitization.

Eighty weed pollen sensitized patients (41 to mugwort and 39 to English plantain) were assessed retrospectively regarding their clinical anamnesis, in-vivo tests (skin prick test [SPT] and allergen specific provocation) and in-vitro tests (immunoglobulin E [IgE] reactivity to purified natural allergen extract and specific allergen components in serum).

85% of mugwort and 83% of English plantain sensitizations could be diagnosed by SPT alone. Distinction between allergic and non-allergic patients could be made with clinical challenges solely. IgE serology revealed IgE antibodies against the native pollen extracts for mugwort in 98% and for English plantain in 90% of patients. Detection of major allergens nArt v 1, nArt v 3 and Pla l 1 did not add accuracy to the diagnosis. A vast majority of the weed pollen allergic patients was sensitized to >1 allergen. Minor allergens were found to be of less importance.

The exact diagnosis of weed pollen allergy can be challenging due to confounding components in anamnesis and diagnostic tests. IgE-serology does not delineate allergic from sensitized patients. Component resolved diagnostics (CRD) can confirm, but not replace, extract based diagnostic methods, such as SPT, provocation tests or serology to native extracts. Hence, these are the gold standard diagnostic tools in weed pollen allergy up to now.