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

Abstract

expiratory flow at 25% to 75% of pulmonary volume as well as higher biomarker elevations in both nasal messenger RNA of CXCL-10 and protein expression of CXCL8, CXCL10, CCL-2, and CCL-4 when compared with virusnegative asymptomatic conditions. Mild virus-positive colds (symptoms scores 1-4) and asymptomatic infections showed normal airway function by spirometry and fewer biomarker elevations. Viral-negative coldlike illnesses had increased nitric oxide with otherwise normal spirometry.CONCLUSIONS: Urban children with asthma have reduced forced expiratory flow at 25% to 75% of pulmonary volume and higher elevations of nasal biomarkers during highsymptom respiratory infections compared with low-symptom infections or symptomatic virus-negative illnesses.REVIEWER COMMENTS: Researchers in this study prospectively evaluate the effect of viral infections on respiratory symptoms and lung function in urban children with asthma. High-symptom colds were associated with decreases in small airway function compared with lower-symptom illnesses. Interestingly, the nasal biomarkers elevated during symptomatic viral infections were related to neutrophil recruitment and not eosinophil or allergic response. Also, many upper respiratory tract illnesses in the study were virus negative, suggesting other triggers for symptoms.