Severe or life‐threatening asthma exacerbation: patient heterogeneity identified by cluster analysis

Abstract

SummaryBackground Severe or life-threatening asthma exacerbation is one of the worst outcomes of asthma because of the risk of death. To date, few studies have explored the potential heterogeneity of this condition.Objectives To examine the clinical characteristics and heterogeneity of patients with severe or life-threatening asthma exacerbation.Methods This was a multicentre, prospective study of patients with severe or life-threatening asthma exacerbation and pulse oxygen saturation < 90% who were admitted to 17 institutions across Japan. Cluster analysis was performed using variables from patient-and physicianorientated structured questionnaires.Results Analysis of data from 175 patients with severe or life-threatening asthma exacerbation revealed five distinct clusters. Cluster 1 (n = 27) was younger-onset asthma with severe symptoms at baseline, including limitation of activities, a higher frequency of treatment with oral corticosteroids and short-acting beta-agonists, and a higher frequency of asthma hospitalizations in the past year. Cluster 2 (n = 35) was predominantly composed of elderly females, with the highest frequency of comorbid, chronic hyperplastic rhinosinusitis/nasal polyposis, and a long disease duration. Cluster 3 (n = 40) was allergic asthma without inhaled corticosteroid use at baseline. Patients in this cluster had a higher frequency of atopy, including allergic rhinitis and furred pet hypersensitivity, and a better prognosis during hospitalization compared with the other clusters. Cluster 4 (n = 34) was characterized by elderly males with concomitant chronic obstructive pulmonary disease (COPD). Although cluster 5 (n = 39) had very mild symptoms at baseline according to the patient questionnaires, 41% had previously been hospitalized for asthma. Conclusions & Clinical RelevanceThis study demonstrated that significant heterogeneity exists among patients with severe or life-threatening asthma exacerbation. Differences were observed in the severity of asthma symptoms and use of inhaled corticosteroids at baseline, and the presence of comorbid COPD. These findings may contribute to a deeper understanding and better management of this patient population.

Developments in the field of allergy in 2016 through the eyes of Clinical and Experimental Allergy

“…Cluster analyses are being brought to bear on more complex clinical issues. In this paper, Seikiya et al confirm previous observations that severe asthma exacerbations arise in clusters with underlying severity, in those with multiple comorbidities especially among women, those not using ICS and interestingly among symptomatically mild patients who had had a previous hospital admission for asthma, one of the strongest predictors of severe exacerbations …”

“…In this paper, Seikiya et al confirm previous observations that severe asthma exacerbations arise in clusters with underlying severity, in those with multiple comorbidities especially among women, those not using ICS and interestingly among symptomatically mild patients who had had a previous hospital admission for asthma, one of the strongest predictors of severe exacerbations. 109 In a longitudinal study of severe poorly controlled asthma, Walsh et al 110 showed that sputum eosinophilia (but not sputum neutrophilia) is a strong predictor of asthma exacerbations. This supports the clinical experience with these severe allergic patients.…”

Changes in the prevalence of asthma and respiratory symptoms in western Sweden between 2008 and 2016

“…Asthma creates a large burden on society including high societal costs . It can reduce quality of life of patients, increase the rate of morbidity and co‐morbidity, and can be life‐threatening . Worldwide about 250 000 deaths are attributed to asthma annually .…”

Asthma and the Risk of Rheumatoid Arthritis: An Insight into the Heterogeneity and Phenotypes of Asthma

“…While there is important progress in characterizing patients with asthma in relation to endotypes and genotypes revealing potential pathways overlapping with ARC46, there is still a long way to go in this research area as none of the previous cluster analyses or phenotypic characterization studies included ARC as a phenotype of asthma138139140141142143144145146147148149150151152153154. We believe that studying the mechanistic pathways underlying the association between asthma and the risk of RA or other ARC may advance our understanding of the nature of asthma and ARC, and it will ultimately benefit scientists and clinicians in understanding the nature of chronic proinflammatory diseases by providing insight into the diseases.…”