Mild to Moderate Asthma in Children Is Heterogeneous With Difficult to Predict Outcomes

In children with mild to moderate asthma, when a latent class analysis (LCA) was performed, results showed that compared with adults, the phenotypic characterization of pediatric patients with asthma remains limited, resulting in difficulty predicting which children are at highest risk for poor outcomes. Findings from the analysis were published in The Journal of Allergy and Clinical Immunology: In Practice.

Investigators sought to identify latent classes of asthma in a large population of treatment-adherent children with mild to moderate asthma who were enrolled in clinical trials. They also aimed to establish whether latent class assignment is predictive of exacerbation rates and future lung function abnormalities in this population. LCA was performed on 8 National Heart, Lung, and Blood Institute phase 3 clinical trials, which totaled 2593 children between aged 5 and 18 years. In the study population, 19 variables were included that encompassed demographics, medical history, lung function, symptoms, allergic sensitization, and type 2 inflammatory markers.

Overall, a total of 5 latent classes were identified, with varying demographic characteristics, sensitization, lung function, asthma control, and type 2 inflammatory markers. The classes were labeled as follows:

• Class 1: Multiple sensitization with partially reversible airflow limitation
• Class 2: Multiple sensitization with reversible airflow limitation
• Class 3: Lesser sensitization with reversible airflow limitation
• Class 4: Multiple sensitization with normal lung function
• Class 5: Lesser sensitization with normal lung function

Class 1 included 244 children, class 2 was the largest class with 926 children, class 3 included 315 children, class 4 included 718 children, and class 5 included 390 children. Days to end of follow-up were 316±95 for all participants. Exacerbations occurred by the end of follow-up in 41.3% of children (class 1, 52.5%; class 2, 41.6%; class 3, 36.8%; class 4, 43.0%; and class 5, 34.1%; P <.001).

Compared with the other classes, latent class 1 had more cumulative exacerbations and a significantly higher annualized exacerbation rate (class 1, 1.30±0.12; class 2, 0.90±0.05; class 3, 0.87±0.08; class 4, 0.87±0.05; and class 5; 0.71±0.07; P <.001).

The investigators concluded that allergic sensitization and lung function may be particularly useful parameters for the identification of children with asthma who are at greatest risk for future disease exacerbations. Children with multiple sensitization appear to be a particularly vulnerable group who may warrant more aggressive therapy.

Additional research is merited, in order to establish whether latent classes are related to meaningful phenotypes for the personalized treatment of patients with asthma.

Reference

Fitzpatrick AM, Bacharier LB, Jackson DJ, et al. Heterogeneity of mild-to-moderate persistent asthma in children: confirmation by latent class analysis and association with one-year outcomes [published online March 7, 2020]. J Allergy Clin Immunol Pract. doi:10.1016/j.jaip.2020.02.032