Relationship between past airway pathology and current lung function in preschool wheezers

Abstract

The functional outcome in preschool severe wheezers with eosinophilic airway inflammation and increased reticular basement membrane (RBM) thickness is unknown. We investigated the relationship between airway pathology at age 2 yrs and lung function at age 4-6 yrs in previous severe wheezers.Severe wheezers previously investigated by endobronchial biopsy and healthy children aged 4-6 yrs were recruited. Lung clearance index (LCI), conducting zone ventilation inhomogeneity (Scond), acinar ventilation inhomogeneity by multiple-breath washout, plethysmographic-specific airway resistance and exhaled nitric oxide fraction (FeNO) were measured. Lung function was compared between wheezers and healthy controls, and in wheezers correlated with past RBM thickness and mucosal eosinophilia (EG2+ cells).72 healthy controls and 28 previous severe wheezers were tested. Wheezers had significantly higher median LCI (6.8 versus 6.6; p50.001) and Scond (0.046 versus 0.016; p,0.0005) than healthy controls. Past RBM thickness (r50.474, p50.047) and EG2+ cells (r50.552, p50.041) showed significant correlations with current FeNO, but no correlations were seen between past RBM thickness and current lung function.RBM thickness and EG2+ cells at age 2 yrs show a significant positive association with FeNO at age 5 yrs. Although lung function was abnormal at age 5 yrs in severe wheezers, this did not correlate with past RBM thickness.

Abnormal Small Airways Function in Children With Mild Asthma

“…Most pediatric studies were done in patients with moderate to severe asthma or with frequent wheeze. [14][15][16][17]19,36,37 Similar to the present data, these studies showed that measures of regional ventilation heterogeneity (ie, conductive ventilation heterogeneity, acinar ventilation heterogeneity) discriminated between patients with asthma and control subjects better than measures of global ventilation heterogeneity either not or weakly correlated to acinar and global ventilation heterogeneity. Interestingly, SDTG was associated the strongest with FEF 25%-75% , a mea sure of more peripheral obstruction than FEV 1 .…”

Predicting who will have asthma at school age among preschool children

“…Children with MTW had a thicker reticular basement membrane and more mucosal eosinophilic inflammation than children with EW. 17 These findings are in concordance with a report showing that children with respiratory symptoms apart from colds had more eosinophils and a thicker basement membrane in their bronchial biopsy specimens than healthy control subjects. 18 Overall, there is a small number of studies reporting on MTW and EW, providing conflicting results as to whether MTW and EW differ in clinical features at preschool age.…”

Classification and pharmacological treatment of preschool wheezing: changes since 2008

“…Despite significant differences in clinical presentation, lung function and genetics between children with EVW and MTW phenotypes, there is a large overlap between the groups [16][17][18][19]. While some children retain a consistent pattern of EVW or MTW over longer periods, symptom patterns change over time in many [15].…”