Comorbidities associated with severe asthma

How Does Mild Asthma Differ Phenotypically from Difficult-to-Treat Asthma?

Background

Despite most of the asthma population having mild disease, the mild asthma phenotype is poorly understood. Here, we aim to address this gap in knowledge by extensively characterising the mild asthma phenotype and comparing this with difficult-to-treat asthma.

Methods

We assessed two real-world adult cohorts from the South of England using an identical methodology: the Wessex AsThma CoHort of difficult asthma (WATCH) (n=498) and a mild asthma cohort from the comparator arm of the Epigenetics Of Severe Asthma (EOSA) study (n=67). Data acquisition included detailed clinical, health and disease-related questionnaires, anthropometry, allergy and lung function testing, plus biological samples (blood and sputum) in a subset.

Results

Mild asthma is predominantly early-onset and is associated with type-2 (T2) inflammation (atopy, raised fractional exhaled nitric oxide (FeNO), blood/sputum eosinophilia) plus preserved lung function. A high prevalence of comorbidities and multimorbidity was observed in mild asthma, particularly depression (58.2%) and anxiety (56.7%). In comparison to difficult asthma, mild disease showed similar female predominance (>60%), T2-high inflammation and atopy prevalence, but lower peripheral blood/airway neutrophil counts and preserved lung function. Mild asthma was also associated with a greater prevalence of current smokers (20.9%). A multi-component T2-high inflammatory measure was comparable between the cohorts; T2-high status 88.1% in mild asthma and 93.5% in difficult asthma.

Conclusion

Phenotypic characterisation of mild asthma identified early-onset disease with high prevalence of current smokers, T2-high inflammation and significant multimorbidity burden. Early comprehensive assessment of mild asthma patients could help prevent potential later progression to more complex severe disease.

Toward a better understanding of severe asthma phenotypes in Latin America: results from the PREPARE study

OBJECTIVE

Data on severe asthma phenotypes in Latin America are lacking. The PREPARE study describes the prevalence of certain determinants of severe asthma among patients in 5 Latin American countries with blood eosinophil counts (BEC) ≥300 cells/mm³ and serum immunoglobulin E (IgE) concentrations >100 IU/mL.

METHODS

In this cross-sectional study, information on demographics, disease characteristics, and asthma treatments were extracted from the existing medical records of patients aged ≥12 years attending centers specialized in severe asthma management. Medical record data were transcribed onto electronic case report forms. Blood eosinophil counts and IgE concentrations were assayed from specimens obtained at study visit. Data were analyzed with descriptive statistics.

RESULTS

Data from 461 patients with severe asthma (mean age, 50.5 years) were analyzed. Most patients were female (73%), had a body mass index of ≥25 kg/m² (77%), and received full healthcare reimbursement (63%). In the previous 12 months, 52% of patients experienced ≥1 severe exacerbation and 44% received oral corticosteroid burst therapy. Blood eosinophil counts ≥300 cells/mm³ and ≥150 cells/mm³ were reported in 44% and 76% of patients, respectively. In 58% of patients, serum IgE concentrations exceeded 100 IU/mL. Uncontrolled asthma was documented in 50% (n = 230) of patients.

CONCLUSIONS

The PREPARE study provides useful insights about the prevalence of eosinophilic and atopic phenotypes in patients with severe asthma in Latin America, thereby paving the way for a more personalized approach to managing severe asthma. Notwithstanding the treatment at specialized medical centers, disease burden remained high in this study population.