Allergic inflammation ups the risk of thunderstorm asthma: Study
Australia: People with allergic inflammation are at a higher risk for developing thunderstorm asthma (TA), concludes a recent study in The Journal of Allergy and Clinical Immunology.
According to the study, in individuals with seasonal allergic rhinitis (SAR), clinical tests can identify the risk of a history of TA and thereby inform patient-specific treatment recommendations.
"Thunderstorm asthma" is said to be triggered by the combination of humidity, wind, and lighting, which ruptures grass pollen and mold spores and breaks them into aerosolized particles. Such particles could lead to asthma symptoms and exacerbations. Following a thunderstorm in 2016 in Melbourne, Australia, 3400 excess asthma emergency department visits and 10 asthma fatalities were recorded. SAR is present in the vast majority of people who develop thunderstorm asthma, but there is not much evidence regarding risk factors for TA among the SAR population.
Against the above background, Jo A. Douglass, Department of Medicine, The University of Melbourne, Parkville, Australia, and colleagues aimed to identify risk factors for a history of TA and hospital presentation in a cohort of individuals with SAR in a multicenter study.
The study recruited adults from Melbourne, Australia, with a past diagnosis of TA and/or self-reported SAR. To identify risk factors for a history of TA in individuals with SAR, the researchers measured spirometry results, clinical information, ryegrass pollen–specific (RGP-sp) IgE concentration, white blood cell count, and fractional exhaled nitric oxide.
Based on the study, the researchers reported the following findings:
· From a total of 228 individuals with SAR, 35% reported SAR only (the I-SAR group), 37% reported TA symptoms but had not attended hospital for treatment (the O-TA group), and 28% had presented to the hospital for TA (the H-TA group).
· All patients in the H-TA group reported a previous asthma diagnosis.
· Logistic regression analysis of factors associated with O-TA and H-TA indicated that a lower FEV1 value and an Asthma Control Questionnaire score higher than 1.5 were associated with H-TA.
· Higher blood RGP-sp IgE concentration, eosinophil counts, and fractional exhaled nitric oxide levels were significantly associated with both O-TA and H-TA.
· Receiver operating curve analysis showed an RGP-sp IgE concentration higher than 10.1 kU/L and a prebronchodilator FEV1 value of 90% or lower to be biomarkers of increased H-TA risk.
To conclude, clinical tests can identify the risk of a history of TA in individuals with SAR and thereby inform patient-specific treatment recommendations.
Reference:
Douglass JA, Lodge C, Chan S, Doherty A, Tan JA, Jin C, Stewart A, Southcott AM, Gillman A, Lee J, Csutoros D, Hannan L, Ruane L, Barnes S, Irving L, Harun NS, Lachapelle P, Spriggs K, Sutherland M, See K, McDonald CF, Conron M, Radhakrishna N, Worsnop C, Johnston FH, Davies JM, Bryant V, Iles L, Ranson D, Spanos P, Vicendese D, Lowe A, Newbigin EJ, Bardin P, Dharmage S. Thunderstorm asthma in seasonal allergic rhinitis: The TAISAR study. J Allergy Clin Immunol. 2022 May;149(5):1607-1616. doi: 10.1016/j.jaci.2021.10.028. Epub 2021 Nov 11. PMID: 34774618.
