Creating A Risk Assessment Tool for Thunderstorm Asthma: the CARISTA Study

Overview

Thunderstorm asthma is a recurring public health emergency in South-Eastern Australia which occurs in springtime. The major identified risk factors for thunderstorm asthma is hay fever and allergy to ryegrass pollen. The goal of the CARISTA study is to identify the risk of springtime allergic and thunderstorm asthma in allergic adults living in South-Eastern Australia. To do this the investigators will recruit 530 people who have hay fever and test them for allergy to ryegrass pollen and undertake simple lung function testing. The investigators will ask study participants to complete a customised symptom tracker over the springtime pollen season for 2 consecutive years. The outcome the investigators are looking for is an asthma exacerbation or worsening asthma symptoms. This study will enable the investigators to identify indicators (biomarkers) of severe and moderate asthma exacerbations in order to identify those at risk of thunderstorm and seasonal asthma so protective treatments and strategies can be advised.

Thunderstorm asthma is a recurring public health emergency in South-Eastern Australia with increasing risks due to climate change. Yet thunderstorm asthma is only the "tip of the iceberg" of documented seasonal surges in emergency asthma presentations due to ryegrass pollen allergy - an escalating challenge to healthcare provision in South-Eastern Australia. The CARISTA (Creating A Risk assessment biomarker tool to prevent Seasonal allergic and Thunderstorm Asthma) study aims to address these profound health impacts. The CARISTA study will recruit adults at high risk of seasonal allergic asthma and thunderstorm asthma who will be monitored using a customised secure data platform for asthma and allergic rhinitis symptoms over two consecutive spring seasons (2025/2026/2027). Participants with self-reported or diagnosed seasonal allergic rhinitis and/or seasonal allergic asthma will be recruited before springtime and their baseline allergic rhinitis and/or asthma symptoms, respiratory function and blood biomarkers (allergy or sensitisation to ryegrass pollen, levels of inflammatory cells \[eosinophils\]) will be measured. The key symptoms of interest are moderate or severe asthma exacerbations which are defined as an increase in asthma symptoms requiring intervention with an emergency medical visit, use of oral corticosteroid therapy or of regular preventive asthma therapy. These asthma exacerbations will be used to establish a biomarker-based estimate of risk for seasonal allergic asthma exacerbations to inform preventive clinical practice. The key biomarker will be the threshold of serum specific IgE (sp-IgE) to ryegrass pollen and its allergen sub-components, but other biomarkers such as lung function, eosinophil levels, and allergen component sensitisation will be simultaneously assessed. This study brings together a team of world-leading multidisciplinary and cross-sectoral clinicians and researchers in Respiratory Medicine, Allergy, Primary Health Care, Epidemiology, Public Health, Statistical modelling and Botany from multiple health and academic institutions. Overall, CARISTA will test a new approach to predict risk for seasonal allergic asthma to identify treatable traits for preventing seasonal allergic asthma exacerbations to reduce the recurrent annual health threat of seasonal and thunderstorm asthma, address community and health care provider concerns and uncertainty regarding preventive treatment and management.