Grapevine pollen allergy J30.- H10.1 K52.1 L50.0

Identified and accepted allergens of Ambrosia artemisiifolia (Short ragweed):

• Amb a 1 pectate lyase (major allergen; is considered a marker specific to ragweed. Cross-reactivity with species v 6; >60% of patients with Amb a 1 sensitization reacts positively to species v 6)
• Amb a 3 Plastocyanins
• Amb a 4 Defensin-like protein (69% sequence identity with species v 1; primary sensitization rather unusual)
• Amb a 6 Non-specific lipid transfer protein type 1
• Amb a 7 Plastocyanin
• Amb a 8 Profilin
• Amb a 9 Polcalcin
• Amb a 10 Polcalcin-like protein (4 EF hands)
• Amb a 11 Cysteine protease

The described cross-reactions are a good explanation for the frequent coincidence of mugwort and pigeonweed allergies. Furthermore, there are cross allergies between herbal pollen and food. Example: Ragweed melon-banana syndrome.

Ragweed species are among the most important allergy triggers worldwide. In the USA, about 10% of the population is sensitized to pollen of various ragweed species.

The plant can cause severe type I allergies in humans through pollen allergens (see pollen below), but also through skin contact with the inflorescence. Ragweed (Ambrosia artemisiifolia, ragweed) is increasingly spreading in Europe. Ambrosia pollen is known for its high allergenic potential; there is cross-reactivity to mugwort pollen. Ragweed-sensitized patients often show polyvalent sensitization to seasonal aeroallergens.

In a larger unselected group with allergic rhinoconjunctivitis of a Munich working group, ragweed sensitization was present in 28.3%. > 50% of patients sensitized to ragweed were also sensitized to mugwort pollen. In about 25% of the ragweed sensitized patients a clinically relevant allergy could be detected.

Main allergen is Amb a1; cross-reactivities exist within the asteracea family (e.g. with false ragweed, chamomile or mugwort). Cross-reactivities to melon and banana are also known ( ragweed-banana-melon syndrome).

1. Bacsi A et al (2006) Subpollen particles of allergic proteins and oxidases. J Allergy Clin Immunol 118: 844-850
2. Frank U et al (2014) Mugwort ambrosia (Ambrosia artemisiifolia): How does ragweed pollen react to different air pollution? A systems biology approach. Allergo J 23: 233
3. McIntyre MS et al (2011) Ambrosia sensitisation in Bavaria: Results of a three-year study on clinical relevance. Abstract CD 46th DDG-Conference FV02/06
4. Wobser J et al (2015) What is the clinical relevance of a sensitization to ragweed pollen proven in the skin prick test? JDDG 13 (Suppl 1) 71-72