Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Nov 4;4(1):100366.
doi: 10.1016/j.jacig.2024.100366. eCollection 2025 Feb.

Subtype prevalence and treatment implication in adolescents and adults with mild-to-moderate asthma: Systematic review and meta-analysis

Chamard Wongsa  1 , Pakpoom Wongyikul  2   3 , Piyaporn Chokevittaya  1 , Anapat Nititammaluk  1 , Kay Khine Soe  4 , Phichayut Phinyo  2   3   5 , Jonathan A Bernstein  6 , Torpong Thongngarm  1
Affiliations

Subtype prevalence and treatment implication in adolescents and adults with mild-to-moderate asthma: Systematic review and meta-analysis

Chamard Wongsa et al. J Allergy Clin Immunol Glob. .

Abstract

Background: Inhaled corticosteroid (ICS)-containing regimens are the mainstay for treating asthma despite usually being ineffective in noneosinophilic asthma (NEA). Data on the prevalence of NEA versus eosinophilic asthma (EA) in mild-to-moderate asthma are limited.

Objective: We performed a systematic review of the prevalence of mild-to-moderate asthma in adolescents and adults using sputum inflammatory cell analysis and their responses to ICS.

Methods: We searched electronic databases (PubMed, Scopus, EMBASE, Cochrane) for studies in adolescents and adults with mild-to-moderate asthma. The primary outcome was the prevalence of asthma subtypes based on sputum inflammatory cell analysis, categorized into EA and NEA. The secondary outcome involved comparing asthma outcomes between different subtypes after ICS therapy. Certainty of evidence was reported for each pooled analysis.

Results: Eighteen studies involving 3,533 adolescents and adults with mild-to-moderate asthma were reviewed. The pooled prevalence (95% confidence interval) of NEA was estimated at 40.39% (27.54, 53.93) in patients with ICS naive with very low certainty of evidence. On reevaluating sputum cytology, the disease of approximately 20% to 30% of patients initially diagnosed as NEA transitioned to the EA subtype. EA patients showed significant improvements in asthma symptoms after ICS therapy: forced expiratory volume in 1 second (standardized mean difference, 0.79; 95% confidence interval, 0.30, 1.27), and airway hyperresponsiveness (standardized mean difference, 1.34; 95% confidence interval, 0.29, 2.40). NEA patients exhibited limited response.

Conclusion: A high proportion of adolescents and adults with mild-to-moderate asthma were identified with NEA subtype disease, which exhibited a poor response to ICS. A thorough diagnostic evaluation before initiating treatment should be integrated into clinical practice.Registered in PROSPERO (CRD42023484334).

Keywords: Asthma; corticosteroid; efficacy; eosinophilic; glucocorticoid; meta-analysis; noneosinophilic; prevalence; subtypes; systematic review.

PubMed Disclaimer

Conflict of interest statement

Disclosure of potential conflict of interest: C. Wongsa has received honoraria for scientific lectures from A. Menarini, Astra-Zeneca, GSK, Novartis, Sanofi, Takeda, and Abbott; and research support from Abbott and Sanofi. J. A. Bernstein has received funding from Novartis, Genentech, Amgen, Sanofi Regeneron, GSK, and Astra Zeneca. T. Thongngarm has received honoraria for scientific lectures from A. Menarini, Astra-Zeneca, GSK, 10.13039/100004336Novartis, P&G, 10.13039/100004339Sanofi, Takeda, and Viatris; has received research support from Abbott, Sanofi, and Viatris; and has served on the advisory board for Sanofi and Viatris. The rest of the authors declare that they have no relevant conflicts of interest. Declaration of generative AI– and AI-assisted technologies: The graphical abstract was created by Canva Pro/Chamard Wongsa. After the creation process, the authors carefully reviewed and edited all content, and they take full responsibility for the accuracy and integrity of this publication.

Figures

None
Graphical abstract
Fig 1
Fig 1
PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) flow diagram of included and excluded studies.
Fig 2
Fig 2
Risk of bias assessment of included studies. Green indicates low risk of bias of each domain; red, high risk.
Fig 3
Fig 3
Forest plots showing pooled noneosinophilic subtype prevalence of adolescents and adults with mild-to-moderate asthma who were (A) ICS naive and who were (B) ICS naive with ICS withdrawal.
Fig 4
Fig 4
Forest plot showing pooled SMD of mean changes from baseline in FEV1 after treatment with ICS compared between EA and NEA.
Fig 5
Fig 5
Forest plot showing pooled SMD of mean changes from baseline in provocative concentration causing 20% decrease in FEV1 (PC20) after ICS treatment compared between EA and NEA.
See this image and copyright information in PMC

References

    1. Global Initiative for Asthma (GINA) Global strategy for asthma management and prevention, 2024 update. https://ginasthma.org/archived-reports/ Available at:
    1. de Farias C.F., Amorim M.M., Dracoulakis M., Caetano L.B., Santoro I.L., Fernandes A.L. Nasal lavage, blood or sputum: which is best for phenotyping asthma? Respirology. 2017;22:671–677. - PubMed
    1. Carr T.F., Zeki A.A., Kraft M. Eosinophilic and noneosinophilic asthma. Am J Respir Crit Care Med. 2018;197:22–37. - PMC - PubMed
    1. Schleich F.N., Manise M., Sele J., Henket M., Seidel L., Louis R. Distribution of sputum cellular phenotype in a large asthma cohort: predicting factors for eosinophilic vs neutrophilic inflammation. BMC Pulm Med. 2013;13:11. - PMC - PubMed
    1. Shi B., Li W., Hao Y., Dong H., Cao W., Guo J., et al. Characteristics of inflammatory phenotypes among patients with asthma: relationships of blood count parameters with sputum cellular phenotypes. Allergy Asthma Clin Immunol. 2021;17:47. - PMC - PubMed

LinkOut - more resources