Patients with asthma have high rates of type 2 inflammatory disease, study finds.
A new study of nearly a quarter-million patients with asthma found a high percentage have at least one co-existing type 2 (cT2) inflammatory disease, and patients with a higher inflammatory disease burden are more likely to experience asthma exacerbations.
Writing in the Journal of Asthma and Allergy, corresponding author David Price, MD, of the University of Aberdeen in Scotland, and colleagues explained that while asthma is a heterogeneous disease, most patients with asthma have type 2 asthma, which is characterized by type 2 inflammation driven by cytokines like interleukins 4 and 5.
“Asthma is increasingly considered to be part of a multimorbidity syndrome, and a large proportion of asthma patients report symptoms of cT2 inflammatory diseases, such as eczema/atopic dermatitis, chronic rhinosinusitis with nasal polyposis, eosinophilic esophagitis, allergic rhinitis, or food allergies,” Price and colleagues wrote.
Reports have been published highlighted the prevalence of cT2 inflammatory diseases among patients with asthma, but such reports have been based on patient self-reports, rather than medical service encounters and diagnoses, the authors said.
In the new report, the investigators used real-world data to calculate rates of cT2s and the impact of those co-morbidities on patients with asthma. They used an original data set of medical records from 4.5 million patients of 650 primary care practices in the United Kingdom between 2010 and 2017. Patients were included if they had at least 1 diagnosis code for asthma and at least 2 asthma-related prescriptions in the year before the index date. Patients were assigned a cT2 burden score (ranging from 0-9) depending on the total number of co-existing conditions with which they had been diagnosed.
After exclusions for factors such as chronic lower respiratory diseases, including chronic obstructive pulmonary disorder (COPD), the investigators were left with a total 245,893 patients with asthma. The mean (SD) age of the group was 44.8 years (22.1), and 43.8% were male.
The authors found that 55% of patients with Global Initiative for Asthma (GINA) step 1 asthma (the least severe) had a medical diagnosis for at least 1 other type 2 inflammatory disease. Among patients with GINA step 5 asthma (the highest step on the scale), 60% had at least 1 other type 2 inflammatory disease diagnosis.
Moreover, the investigators found that the higher the cT2 burden score, the more likely a patient was to experience asthma exacerbations, and the less likely the patient was to achieve asthma control.
Price and colleagues said they believe theirs to be the first study to show how multiple cT2s—beyond allergic rhinitis—can impact asthma control. They said their findings align with earlier research suggesting that patients with cT2s are more likely to experience exacerbations.
They concluded that their findings ought to prompt physicians to reconsider the risk profile of patients with asthma and other inflammatory diseases.
“Given that the presence of cT2 complicates the management of asthma and is associated with higher risk of exacerbations and lower asthma control, clinicians may consider the assessment of type 2 comorbidity burden in their evaluation of patients with moderate-to-severe asthma,” they wrote.
Price D, Menzies-Gow A, Bachert C, et al. Association between a type 2 inflammatory disease burden score and outcomes among patients with asthma. J Asthma Allergy. Published online September 29, 2021. doi:10.2147/JAA.S321212