Common Ragweed Allergy Under Global Change Linking Invasion-Driven Aeroallergen Exposure with Molecular Sensitization and Allergic Airway Disease.

The case of common ragweed (Ambrosia artemisiifolia) stands as a prime example of an invasive plant that links global change, biological invasion, aeroallergen exposure, and allergic airway disease. However, evidence remains fragmented across invasion biology, aerobiology, molecular allergology, and respiratory medicine. By separating plant occurrence, pollen abundance, molecular allergen dose, sensitisation, and airway disease, this review develops an integrated invasion-exposure-disease logic for interpreting ragweed-related health risk. We examine how climate change, land-use disturbance, repeated introductions, rapid adaptation, and air pollution influence plant distribution, flowering phenology, pollen production, airborne allergen load, and respiratory outcomes. Attention is given to Amb a 1 as the principal marker of genuine ragweed sensitisation, cross-reactivity with Artemisia and other weed pollens, allergen-bearing respirable particles, and the diagnostic limitations of extract-based immunoglobulin E (IgE) testing. The literature indicates that ragweed sensitisation follows a pronounced hotspot-gradient pattern in Europe, whereas patterns in other invaded regions remain more heterogeneous and incompletely characterised. Clinically relevant exposure depends not only on pollen concentration but also on airborne allergen load, pollen allergen potency, atmospheric transport, respirable particle fractions, meteorological conditions, and pollution. Ragweed-related airway disease is mediated by IgE-dependent type 2 immunity and amplified by epithelial danger signals, oxidative stress, protease activity, and innate immune pathways. Based on current evidence, we propose that an integrated surveillance framework linking plant distribution, pollen and airborne-allergen exposure, molecular sensitisation, symptoms, lung function, and asthma outcomes could strengthen risk forecasting, source attribution, prevention, and invasion control of the common ragweed.