D2.389 - A Dynamic Interaction Between the Immune System, the Exposome, and Climate Change: The Shifting Sensitization Profile to Respiratory Allergens Across Life

The sensitization profile to respiratory allergens evolves throughout life, reflecting both physiological remodeling of the immune system and the impact of the exposome — the cumulative influence of environmental and lifestyle factors. 

Objective: To investigate age-related changes in sensitization profiles among children, adolescents, and adults in the context of immune mechanisms interacting with the exposome, including the effects of climate change. 

Methods: Sensitization profiles of 424 patients with respiratory allergies from the International Allergy Center in Tashkent with written informed consent were analyzed using the Alex2 multiplex test (MADx, Austria). Data analysis considered the external exposome, behavioral, and social factors across age cohorts: children (29%), adolescents (30%), and adults (41%). A specially designed patient questionnaire and data from the Hydrometeorological Agency under the Ministry of Ecology, Environmental Protection, and Climate Change were used. The data were compared with ERA5, the fifth generation ECMWF global climate atmospheric reanalysis covering the time range from 1979 to 2021 with a spatial resolution of 30 km. 

In children with respiratory allergies in Tashkent, the dominant allergenic molecules were Alternaria alternata (Alt a 1, 51%) and cat allergen (Fel d 1, 42%). Adolescents showed increasing polysensitization, including pollen allergens of grasses (Phl p 1/Phl p 5), conifers (Cup a 1), and plane tree (Pla a 1), while maintaining high sensitization rates to Alt a 1 and Fel d 1 (48% each). Among adults, 73% were polysensitized, with 50% of them showing true sensitization to 3 allergenic sources in variations. The dominant allergens in adults were Phl p 1/Phl p 5 (54%), Fel d 1 (46%), Cup a 1 (36%), and Art v 1 (37%). IgE to Alt a 1 was only in 14,5% of adult patients. The increased exposure to Alternaria due to climate change was associated with accelerated mold growth, spore production, and dissemination. This is particularly driven by changes in the regime and intensity of precipitation and dust storms, peaking in 2021. Over the past decade, the urban “heat island” effect in Tashkent has further promoted higher mold spore levels. 

The age-dependent sensitization profile to respiratory allergens dynamically reflects the interaction between the immune system and the exposome. Climate change directly influences the prevalence and exposure to mold allergens such as Alternaria alternata, explaining higher sensitization rates in children and adolescents compared to adults. Integrating molecular allergology with the planetary health framework offers new horizons for managing allergic diseases amidst global environmental changes.