Phenotypes of Recurrent Wheezing in Preschool Children: Identification by Latent Class Analysis and Utility in Prediction of Future Exacerbation

Publication date: Available online 26 September 2018

Source: The Journal of Allergy and Clinical Immunology: In Practice

Author(s): Anne M. Fitzpatrick, Leonard B. Bacharier, Theresa W. Guilbert, Daniel J. Jackson, Stanley J. Szefler, Avraham Beigelman, Michael D. Cabana, Ronina Covar, Fernando Holguin, Robert F. Lemanske, Fernando D. Martinez, Wayne Morgan, Wanda Phipatanakul, Jacqueline A. Pongracic, Robert S. Zeiger, David T. Mauger, NIH/NHLBI AsthmaNet

Abstract

Background

Recurrent preschool wheezing is a heterogeneous disorder with significant morbidity, yet little is known about phenotypic determinants and their impact on clinical outcomes.

Objective

Latent class analysis (LCA) was used to identify latent classes of recurrent preschool wheeze and their association with future exacerbations and inhaled corticosteroid (ICS) treatment response.

Methods

Data from five clinical trials of 1,708 children age 12-71 months with recurrent wheezing were merged. LCA was performed on 10 demographic, exposure and sensitization variables to determine the optimal number of latent classes. The primary outcome was the annualized rate of wheezing exacerbations requiring systemic corticosteroids during the study intervention period; the secondary outcome was the time to first exacerbation. Exploratory analyses examined the effect of daily ICS treatment on exacerbation outcomes.

Results

Four latent classes of recurrent wheezing were identified; these were not distinguished by current symptoms or historical exacerbations but differed with regard to allergen sensitization and/or exposures. Annualized exacerbation rates (mean ± SEM/year) were 0.65 ± 0.06 for class 1 ("minimal sensitization"), 0.93 ± 0.10 for class 2 ("sensitization with indoor pet exposure"), 0.60 ± 0.07 for class 3 ("sensitization with tobacco smoke exposure"), and 0.81 ± 0.10 for class 4 ("multiple sensitization and eczema") (p < 0.001). In a research setting of high adherence, daily ICS treatment improved exacerbation rates in classes 2 and 4 but not the other groups.

Conclusion

Sensitization and exposure assessments are useful in the prediction of future exacerbation and may identify children most likely to respond favorably to daily ICS treatment.