Giant Ragweed
Summary
Giant ragweed (Ambrosia trifida) is an herbaceous annual weed, native to North America and introduced to many countries in Europe and Asia. It is associated with allergic rhinitis, conjunctivitis and asthma as well as contact dermatitis. Giant ragweed shows high levels of cross-reactivity with other ragweeds (Ambrosia species) and mugwort (Artemisia species).
Epidemiology
Worldwide distribution
Ragweed pollen is an important allergen source: Ambrosia species (of which short ragweed, giant ragweed and western ragweed are the most widespread) are major elicitors of pollen allergy in North America. In a study of 50 Chinese patients (aged 8–54 years) with weed pollen-induced allergic rhinitis, 34 % had specific IgE to giant ragweed allergen, Amb t
Risk factors
Climate change modelling suggests there will be an impact on the giant ragweed distribution area, although whether this will potentially increase or decrease depends on the climate scenario.
Route Of Exposure
Main
The main route of exposure is inhalation.
Clinical Relevance
Giant ragweed pollen causes seasonal allergic rhinitis, asthma and conjunctivitis in sensitized patients as well as contact dermatitis.
Asthma
Giant ragweed pollen can rupture osmotically in the atmosphere, producing sub-pollen particles that penetrate deeper into the respiratory tract than intact pollen grains, potentially triggering severe asthma
Prevention And Therapy
Allergen immunotherapy
Allergenic cross-reactivity exists between Amb a (short or common ragweed), Amb p (western ragweed) and Amb t (giant ragweed), and given the effective Amb b inhibition of Amb p and Amb t suggests that an Amb a-based, single-species allergen immunotherapy may be successful in patients allergic to diverse ragweed pollens, although species-specific immunotherapy may be required given the allergen diversity
Cross-Reactivity
The presence of homologous allergens leads to extensive IgE cross-reactivity between the pollen extracts Amb t from giant ragweed, Amb p from western ragweed (A. psilostachya) and Amb a from short or common ragweed (A. artemisiifolia)
A high degree of IgE cross-reactivity is seen among different species of ragweed (Ambrosia spp) and mugwort (Artemisia) and to other allergenic plants of the Asteraceae family.
References
- CABI. Ambrosia trifida (giant ragweed) Wallingford, UK2021 [cited 2021 14.12.21]. Available from: https://www.cabi.org/isc/datasheet/4693.
- Han D, Lai X, Gjesing B, Zhong N, Zhang L, Spangfort MD. The specific IgE reactivity pattern of weed pollen-induced allergic rhinitis patients. Acta Otolaryngol. 2011;131(5):533-8.
- LOINC. Giant Ragweed triggered histamine release [Units/volume] in Blood 2021 [cited 2021 14.12.21]. Available from: https://loinc.org/7649-7/.
- Matricardi PM, Kleine-Tebbe J, Hoffmann HJ, Valenta R, Hilger C, Hofmaier S, et al. EAACI Molecular Allergology User's Guide. Pediatr Allergy Immunol. 2016;27 Suppl 23:1-250.
- Rasmussen K, Thyrring J, Muscarella R, Borchsenius F. Climate-change-induced range shifts of three allergenic ragweeds (Ambrosia L.) in Europe and their potential impact on human health. PeerJ. 2017;5:e3104.
- Gadermaier G, Dedic A, Obermeyer G, Frank S, Himly M, Ferreira F. Biology of weed pollen allergens. Current Allergy and Asthma Reports. 2004;4(5):391-400.
- Christensen LH, Ipsen H, Nolte H, Maloney J, Nelson HS, Weber R, et al. Short ragweeds is highly cross-reactive with other ragweeds. Ann Allergy Asthma Immunol. 2015;115(6):490-5.e1.
- Würtzen PA, Hoof I, Christensen LH, Váczy Z, Henmar H, Salamanca G, et al. Diverse and highly cross-reactive T-cell responses in ragweed allergic patients independent of geographical region. Allergy. 2020;75(1):137-47.
- Barton JS, Schomacker R. Comparative protein profiles of the Ambrosia plants. Biochim Biophys Acta Proteins Proteom. 2017;1865(6):633-9.